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symmetries and their associated selection rules are extremely useful in all fields of science. in particular, for system that include electromagnetic ( em ) fields interacting with matter, it has been shown that both of symmetries of matter and em field ' s time - dependent polarization play a crucial role in determining the properties of linear and nonlinear responses. the relationship between the system ' s symmetry and the properties of its excitations facilitate precise control over light emission and enable ultrafast symmetry - breaking spectroscopy of variety of properties. here. we formulate the first general theory that describes the macroscopic dynamical symmetries ( including quasicrystal - like symmetries ) of an em vector field, revealing many new symmetries and selection rules in light - matter interactions. we demonstrate an example of multi - scale selection rules experimentally in the framework of high harmonic generation ( hhg ). this work waves the way for novel spectroscopic techniques in multi - scale system as well as for imprinting complex structures in euv - x - ray beams, attosecond pulses, or the interacting medium itself.
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arxiv:2109.01941
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we develop a mathematical model for intraday dispatch of co - located wind - battery energy assets. focusing on the primary objective of firming grid - side actual production vis - a - vis the preset day - ahead hourly generation targets, we conduct a comprehensive study of the resulting stochastic control problem across different firming formulations and wind generation dynamics. among others, we provide a closed - form solution in the special case of a quadratic objective and linear dynamics, as well as design a novel adaptation of a gaussian process - based regression monte carlo algorithm for our setting. extensions studied include an asymmetric loss function for peak shaving, capturing the cost of battery cycling, and the role of battery duration. in the applied portion of our work, we calibrate our model to a collection of 140 + wind - battery assets in texas, benchmarking the economic benefits of firming based on outputs of a realistic unit commitment and economic dispatch solver.
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arxiv:2503.12305
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this work reports the procedure for modeling piezoelectric acoustic resonators and filters at millimeter wave ( mmwave ). different from conventional methods for lower frequency piezoelectric devices, we include both acoustic and electromagnetic ( em ) effects, e. g., self - inductance, in both the circuit - level fitting and finite element analysis, toward higher accuracy at higher frequencies. to validate the method, thin - film lithium niobate ( linbo3 ) first - order antisymmetric ( a1 ) mode devices are used as the testbed, achieving great agreement for both the standalone resonators and a fifth - order ladder filter. upon further development, the reported acoustic and em co - modeling could guide the future design of compact piezoelectric devices at mmwave and beyond.
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arxiv:2405.19591
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audio - driven one - shot talking face generation methods are usually trained on video resources of various persons. however, their created videos often suffer unnatural mouth shapes and asynchronous lips because those methods struggle to learn a consistent speech style from different speakers. we observe that it would be much easier to learn a consistent speech style from a specific speaker, which leads to authentic mouth movements. hence, we propose a novel one - shot talking face generation framework by exploring consistent correlations between audio and visual motions from a specific speaker and then transferring audio - driven motion fields to a reference image. specifically, we develop an audio - visual correlation transformer ( avct ) that aims to infer talking motions represented by keypoint based dense motion fields from an input audio. in particular, considering audio may come from different identities in deployment, we incorporate phonemes to represent audio signals. in this manner, our avct can inherently generalize to audio spoken by other identities. moreover, as face keypoints are used to represent speakers, avct is agnostic against appearances of the training speaker, and thus allows us to manipulate face images of different identities readily. considering different face shapes lead to different motions, a motion field transfer module is exploited to reduce the audio - driven dense motion field gap between the training identity and the one - shot reference. once we obtained the dense motion field of the reference image, we employ an image renderer to generate its talking face videos from an audio clip. thanks to our learned consistent speaking style, our method generates authentic mouth shapes and vivid movements. extensive experiments demonstrate that our synthesized videos outperform the state - of - the - art in terms of visual quality and lip - sync.
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arxiv:2112.02749
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this paper presents an efficient algorithm of high - resolution microwave imaging based on the concept of generalized reflectivity. the contribution made in this paper is two - fold. we introduce the concept of non - parametric generalized reflectivity ( gr, for short ) as a function of operational frequencies and view angles, etc. the gr extends the conventional born - based imaging model, i. e., single - scattering model, into that accounting for more realistic interaction between the electromagnetic wavefield and imaged scene. afterwards, the gr - based microwave imaging is formulated in the convex of sparsity - regularized optimization. typically, the sparsity - regularized optimization requires the implementation of iterative strategy, which is computationally expensive, especially for large - scale problems. to break this bottleneck, we convert the imaging problem into the problem of physics - driven image processing by introducing a dual transformation. moreover, this image processing is performed over overlapping patches, which can be efficiently solved in the parallel or distributed manner. in this way, the proposed high - resolution imaging methodology could be applicable to large - scale microwave imaging problems. selected simulation results are provided to demonstrate the state - of - art performance of proposed methodology.
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arxiv:1611.03341
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) : 514 – 538. doi : 10. 2307 / 1994188. jstor 1994188. soare, robert i. ( 1996 ). " computability and recursion ". bulletin of symbolic logic. 2 ( 3 ) : 284 – 321. citeseerx 10. 1. 1. 35. 5803. doi : 10. 2307 / 420992. jstor 420992. s2cid 5894394. solovay, robert m. ( 1976 ). " provability interpretations of modal logic ". israel journal of mathematics. 25 ( 3 – 4 ) : 287 – 304. doi : 10. 1007 / bf02757006. s2cid 121226261. woodin, w. hugh ( 2001 ). " the continuum hypothesis, part i " ( pdf ). notices of the american mathematical society. 48 ( 6 ). = = = classical papers, texts, and collections = = = banach, stefan ; tarski, alfred ( 1924 ). " sur la decomposition des ensembles de points en parties respectivement congruentes " ( pdf ). fundamenta mathematicae ( in french ). 6 : 244 – 277. doi : 10. 4064 / fm - 6 - 1 - 244 - 277. bochenski, jozef maria, ed. ( 1959 ). a precis of mathematical logic. synthese library, vol. 1. translated by otto bird. dordrecht : springer. doi : 10. 1007 / 978 - 94 - 017 - 0592 - 9. isbn 9789048183296. { { cite book } } : isbn / date incompatibility ( help ) burali - forti, cesare ( 1897 ). a question on transfinite numbers. reprinted in van heijenoort 1976, pp. 104 – 111 cantor, georg ( 1874 ). " ueber eine eigenschaft des inbegriffes aller reellen algebraischen zahlen " ( pdf ). journal fur die reine und angewandte mathematik. 1874 ( 77 ) : 258 – 262. doi : 10. 1515 / crll. 1874. 77. 258. s2cid 199545885. carroll, lewis ( 1896 ). symbolic logic. kessinger legacy reprints. isbn 9781163444955. { { cite book }
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https://en.wikipedia.org/wiki/Mathematical_logic
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we derive formulae for the soft limit of tree - level gluon and graviton correlators in anti - de sitter space, which arise from feynman diagrams encoding the weinberg soft theorems in flat space. other types of diagrams can also contribute to the soft limit at leading order in the soft momentum, but have a different pole structure. we derive these results at four points using explicit formulae recently obtained from the cosmological bootstrap and double copy, and extend them to any multiplicity using bootstrap techniques in mellin - momentum space.
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arxiv:2407.16052
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we give counterexamples to the kawamata - viehweg vanishing theorem on ruled surfaces in positive characteristic, and prove that if there is a counterexample to the kawamata - viehweg vanishing theorem on a geometrically ruled surface f : x - - > c, then either c is a tango curve or all of sections of f are ample.
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arxiv:math/0702554
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[ abridged ] aims : the monos project is collecting information and studying o - type spectroscopic binaries with delta > - 20 deg. in this 2nd paper, we tackle the study of the 35 single - line spectroscopic binary ( sb1 ) systems identified in the previous paper of the series ( arxiv : 1904. 11385 ) by analyzing our data and reviewing the literature orbits of such systems. methods : we have measured the radial velocities for the ~ 700 spectra in our database using two different methods : gaussian fitting for several diagnostic lines per object and cross - correlation using synthetic spectra. we also explored the tess database and analyzed the light curves for 31 of the systems. results : we have confirmed 21 sb1 systems, discarded the binary nature of 6 stars ( 9 sge, hd 192 281, hde 229 232 ab, 68 cyg, hd 108 and \ alpha cam ), and left 6 stars as inconclusive due to lack of data. the remaining two stars are 15 mon aa which has been classified as sb2, and cyg ob2 - 22 c, for which we find evidence that it is most likely a triple system where the o star is orbiting an eclipsing sb1. we have also recalculated 20 new orbital solutions, including the first spectroscopic orbital solution for v747 cep. for cyg ob2 - 22 c we have obtained new ephemerides but no new orbit.
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arxiv:2106.08865
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with the rapid growth of large online social networks, the ability to analyze large - scale social structure and behavior has become critically important, and this has led to the development of several scalable graph processing systems. in reality, however, social interaction takes place not only between pairs of individuals as in the graph model, but rather in the context of multi - user groups. research has shown that such group dynamics can be better modeled through a more general hypergraph model, resulting in the need to build scalable hypergraph processing systems. in this paper, we present mesh, a flexible distributed framework for scalable hypergraph processing. mesh provides an easy - to - use and expressive application programming interface that naturally extends the think like a vertex model common to many popular graph processing systems. our framework provides a flexible implementation based on an underlying graph processing system, and enables different design choices for the key implementation issues of partitioning a hypergraph representation. we implement mesh on top of the popular graphx graph processing framework in apache spark. using a variety of real datasets and experiments conducted on a local 8 - node cluster as well as a 65 - node amazon aws testbed, we demonstrate that mesh provides flexibility based on data and application characteristics, as well as scalability with cluster size. we further show that it is competitive in performance to hyperx, another hypergraph processing system based on spark, while providing a much simpler implementation ( requiring about 5x fewer lines of code ), thus showing that simplicity and flexibility need not come at the cost of performance.
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arxiv:1904.00549
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we calculated the electroweak contributions to the hadronic production of a squark in association with a gluino within the minimal supersymmetric standard model ( mssm ). presented are complete next - to - leading order electroweak ( nlo ew ) corrections at o ( alpha _ s ^ 2 alpha ), which include real photon and real quark radiation processes. also considered are photon induced tree level o ( alpha _ s alpha ) contributions.
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arxiv:0810.1044
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in this paper, we consider the online proximal mirror descent for solving the time - varying composite optimization problems. for various applications, the algorithm naturally involves the errors in the gradient and proximal operator. we obtain sharp estimates on the dynamic regret of the algorithm when the regular part of the cost is convex and smooth. if the bregman distance is given by the euclidean distance, our result also improves the previous work in two ways : ( i ) we establish a sharper regret bound compared to the previous work in the sense that our estimate does not involve $ o ( t ) $ term appearing in that work. ( ii ) we also obtain the result when the domain is the whole space $ \ mathbb { r } ^ n $, whereas the previous work was obtained only for bounded domains. we also provide numerical tests for problems involving the errors in the gradient and proximal operator.
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arxiv:2304.04710
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the purpose of this paper is threefold. first the natural extension of riesz potentials to the context of quasi metric measure spaces for the class of upper doubling measures are studied on lebesgue spaces, obtaining necessary and sufficient conditions on a upper doubling measure. second, we exhibit a geometric property of the measure of the ball which permit prove the boundedness in a unified way, both in of the doubling as non doubling situation. third, we show that the result can be applied to a type riesz potential operator defined over a space formed by two components which are not of necessarily equal dimensions.
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arxiv:1309.3755
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macroscopic fluctuation theory has shown that a wide class of non - equilibrium stochastic dynamical systems obey a large deviation principle, but except for a few one - dimensional examples these large deviation principles are in general not known in closed form. we consider the problem of constructing successive approximations to an ( unknown ) large deviation functional and show that the non - equilibrium probability distribution the takes a gibbs - boltzmann form with a set of auxiliary ( non - physical ) energy functions. the expectation values of these auxiliary energy functions and their conjugate quantities satisfy a closed system of equations which can imply a considerable reduction of dimensionality of the dynamics. we show that the accuracy of the approximations can be tested self - consistently without solving the full non - equilibrium equations. we test the general procedure on the simple model problem of a relaxing 1d ising chain.
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arxiv:1401.4685
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we present hawki, for synthesizing aerial - view images from text and an exemplar image, without any additional multi - view or 3d information for finetuning or at inference. hawki uses techniques from classical computer vision and information theory. it seamlessly blends the visual features from the input image within a pretrained text - to - 2dimage stable diffusion model with a test - time optimization process for a careful bias - variance trade - off, which uses an inverse perspective mapping ( ipm ) homography transformation to provide subtle cues for aerialview synthesis. at inference, hawki employs a unique mutual information guidance formulation to steer the generated image towards faithfully replicating the semantic details of the input - image, while maintaining a realistic aerial perspective. mutual information guidance maximizes the semantic consistency between the generated image and the input image, without enforcing pixel - level correspondence between vastly different viewpoints. through extensive qualitative and quantitative comparisons against text + exemplar - image based methods and 3d / multi - view based novel - view synthesis methods on proposed synthetic and real datasets, we demonstrate that our method achieves a significantly better bias - variance trade - off towards generating high fidelity aerial - view images. code and data is available at https : / / github. com / divyakraman / hawki2024.
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arxiv:2311.15478
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we note that for each k \ in { 0, 1, 2,... } the following holds : ne has ( nonuniform ) acc ^ k circuits if and only if ne has p ^ { ne } - uniform acc ^ k circuits. and we mention how to get analogous results for other circuit and complexity classes.
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arxiv:1012.0556
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in this paper, we introduce the combinatorial multi - objective multi - armed bandit ( como - mab ) problem that captures the challenges of combinatorial and multi - objective online learning simultaneously. in this setting, the goal of the learner is to choose an action at each time, whose reward vector is a linear combination of the reward vectors of the arms in the action, to learn the set of super pareto optimal actions, which includes the pareto optimal actions and actions that become pareto optimal after adding an arbitrary small positive number to their expected reward vectors. we define the pareto regret performance metric and propose a fair learning algorithm whose pareto regret is $ o ( n l ^ 3 \ log t ) $, where $ t $ is the time horizon, $ n $ is the number of arms and $ l $ is the maximum number of arms in an action. we show that como - mab has a wide range of applications, including recommending bundles of items to users and network routing, and focus on a resource - allocation application for multi - user communication in the presence of multidimensional performance metrics, where we show that our algorithm outperforms existing mab algorithms.
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arxiv:1803.04039
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we improve the previous study of the klein - gordon equation in a non - commutative space - time as applied to the hydrogen atom to extract the energy levels, by considering the second - order corrections in the non - commutativity parameter. phenomenologically we show that non - commutativity is the source of lamb shift corrections.
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arxiv:1101.0355
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the operation of large arrays of silicon photomultipliers ( sipm ) in tanks of noble liquids requires low noise, low power front - end amplifiers, able to operate reliably in the cryogenic environment. a suitable amplifier needs to be paired with a proper sipm ganging scheme, meaning the series / parallel combination of sipms at its input. this paper presents a simple model to estimate the ganging scheme that gives the best signal to noise ratio once the basic electrical characteristics of the sipm and amplifier are known. to prove the validity of the model, we used an amplifier based on discrete components, which achieves a white voltage noise in the 0. 25 - 0. 37 nv / $ \ surd $ hz range at liquid nitrogen temperature, while drawing 2 - 5 mw of power. combined with the optimal ganging scheme obtained with the model, the amplifier demonstrated excellent single photon sensitivity up to 96 6x6 mm $ ^ 2 $ sipms ( total area 34. 6 cm $ ^ 2 $, s / n $ \ simeq $ 8 - 11 ). the measured results are in a good match with calculated values, predicting the possibility to achieve a clear separation of photoelectron peaks also with larger areas.
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arxiv:2310.04098
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this paper presents an approach for semantic place categorization using data obtained from rgb cameras. previous studies on visual place recognition and classification have shown that, by considering features derived from pre - trained convolutional neural networks ( cnns ) in combination with part - based classification models, high recognition accuracy can be achieved, even in presence of occlusions and severe viewpoint changes. inspired by these works, we propose to exploit local deep representations, representing images as set of regions applying a na \ " { i } ve bayes nearest neighbor ( nbnn ) model for image classification. as opposed to previous methods where cnns are merely used as feature extractors, our approach seamlessly integrates the nbnn model into a fully - convolutional neural network. experimental results show that the proposed algorithm outperforms previous methods based on pre - trained cnn models and that, when employed in challenging robot place recognition tasks, it is robust to occlusions, environmental and sensor changes.
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arxiv:1702.07898
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a confirmation of the long - standing muon $ g $ - 2 discrepancy requires both experimental and theoretical progress. on the theory side, the hadronic corrections are under close scrutiny, as they induce the leading uncertainty of the standard model prediction. recently, the muone experiment has been proposed at cern to provide a new determination of the leading hadronic contribution to the muon $ g $ - 2 via the measurement of the differential cross section of muon - electron scattering. the precision expected at this experiment raises the question whether possible new - physics ( np ) could affect its measurements. we address this issue studying possible np signals in muon - electron collisions due to heavy or light mediators, depending on whether their mass is higher or lower than $ { \ cal o } ( 1 { \ rm gev } ) $. we analyze the former in a model - independent way via an effective field theory approach, whereas for the latter we focus on scenarios with light scalar and vector bosons. using existing experimental bounds, we show that possible np effects in muon - electron collisions are expected to lie below muone ' s sensitivity. this result confirms and reinforces the physics case of the muone proposal.
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arxiv:2002.05418
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we introduce the notion of intrinsic subspaces of linear and affine pair geometries, which generalizes the one of projective subspaces of projective spaces. we prove that, when the affine pair geometry is the projective geometry of a lie algebra introduced in [ bertram - neeb, j. alg. 277 ], such intrinsic subspaces correspond to inner ideals in the associated jordan pair, and we investigate the case of intrinsic subspaces defined by the peirce - decomposition which is related to 5 - gradings of the projective lie algebra. these examples, as well as the examples of general and lagrangian flag geometries, lead to the conjecture that geometries of intrinsic subspaces tend to be themselves linear pair geometries.
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arxiv:math/0606448
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in this paper, we present a very important primitive called information checking protocol ( icp ) which plays an important role in constructing statistical verifiable secret sharing ( vss ) and weak secret sharing ( wss ) protocols. informally, icp is a tool for authenticating messages in the presence of computationally unbounded corrupted parties. here we extend the basic bare - bone definition of icp, introduced by rabin et al. and then present an icp that attains the best communication complexity and round complexity among all the existing icps in the literature. we also show that our icp satisfies several interesting properties such as linearity property which is an important requirement in many applications of icp. though not presented in this paper, we can design communication and round efficient statistical ( i. e involves negligible error probability in computation ) vss and multiparty computation ( mpc ) protocol using our new icp.
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arxiv:1004.3504
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we discuss a general five - dimensional completely anisotropic holographic model with three different spatial scale factors, characterized by a van der waals - like phase transition between small and large black holes. a peculiar feature of the model is the relation between anisotropy of the background and anisotropy of the colliding heavy ions geometry. we calculate the holographic entanglement entropy ( hee ) of the slab - shaped region, the orientation of which relatively to the beams line and the impact parameter is characterized by the euler angles. we study the dependences of the hee and its density on the thermodynamic ( temperature, chemical potential ) and geometric ( parameters of anisotropy, thickness, and orientation of entangled regions ) parameters. as a particular case the model with two equal transversal scaling factors is considered. this model is supported by the dilaton and two maxwell fields. in this case we discuss the hee and its density in detail : interesting features of this model are jumps of the entanglement entropy and its density near the line of the small / large black hole phase transition. these jumps depend on the anisotropy parameter, chemical potential, and orientation. we also discuss different definitions and behavior of c - functions in this model. the c - function calculated in the einstein frame decreases while increasing $ \ ell $ for all $ \ ell $ in the isotropic case ( in regions of $ ( \ mu, t ) $ - plane far away from the line of the phase transition ). we find the non - monotonicity of the c - functions for several anisotropic configurations, which however does not contradict with any of the existing c - theorems since they all base on lorentz invariance.
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arxiv:2003.05847
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we investigate the suppression of the visibility of aharonov - bohm oscillations in a two - electron mach - zehnder interferometer that leaves the single - electron current unchanged. in the case when the sources emit either spin - polarized or entangled electrons, partial distinguishability of electrons ( coming from two different sources ) suppresses the visibility. two - particle entanglement may produce behavior similar to " dephasing " of two - particle interferometry.
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arxiv:cond-mat/0703186
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we performed all - atom molecular dynamics simulations for bulk cyclohexane and analysed the short - and medium - range structures in supercooled and glassy states by using the voronoi tessellation technique. from the analyses of both the potential energy of the system and the radial distribution function of molecules, cyclohexane was found to be vitrified as the temperature decreased. furthermore, the icosahedral - like structures are dominant at all temperatures and grow in a supercooled liquid, whereas the face - centred cubic structures do not grow when the temperature decreases. it was also ascertained that the icosahedral - like structure is more dominant than the full - icosahedral one. the network of the distorted icosahedron spreads throughout the system at low temperatures. our simulation demonstrates the stability of the icosahedral structure even in a non - spherical molecule such as cyclohexane.
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arxiv:2001.04726
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anomaly detection is a fundamental problem in data mining field with many real - world applications. a vast majority of existing anomaly detection methods predominately focused on data collected from a single source. in real - world applications, instances often have multiple types of features, such as images ( id photos, finger prints ) and texts ( bank transaction histories, user online social media posts ), resulting in the so - called multi - modal data. in this paper, we focus on identifying anomalies whose patterns are disparate across different modalities, i. e., cross - modal anomalies. some of the data instances within a multi - modal context are often not anomalous when they are viewed separately in each individual modality, but contains inconsistent patterns when multiple sources are jointly considered. the existence of multi - modal data in many real - world scenarios brings both opportunities and challenges to the canonical task of anomaly detection. on the one hand, in multi - modal data, information of different modalities may complement each other in improving the detection performance. on the other hand, complicated distributions across different modalities call for a principled framework to characterize their inherent and complex correlations, which is often difficult to capture with conventional linear models. to this end, we propose a novel deep structured anomaly detection framework to identify the cross - modal anomalies embedded in the data. experiments on real - world datasets demonstrate the effectiveness of the proposed framework comparing with the state - of - the - art.
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arxiv:1908.03848
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given access to the vertex set $ v $ of a connected graph $ g = ( v, e ) $ and an oracle that given two vertices $ u, v \ in v $, returns the shortest path distance between $ u $ and $ v $, how many queries are needed to reconstruct $ e $? firstly, we show that randomised algorithms need to use at least $ \ frac1 { 200 } \ delta n \ log _ \ delta n $ queries in expectation in order to reconstruct $ n $ - vertex trees of maximum degree $ \ delta $. the best previous lower bound ( for graphs of bounded maximum degree ) was an information - theoretic lower bound of $ \ omega ( n \ log n / \ log \ log n ) $. our randomised lower bound is also the first to break through the information - theoretic barrier for related query models including distance queries for phylogenetic trees, membership queries for learning partitions and path queries in directed trees. secondly, we provide a simple deterministic algorithm to reconstruct trees using $ \ delta n \ log _ \ delta n + ( \ delta + 2 ) n $ distance queries. this proves that our lower bound is optimal up to a multiplicative constant. we extend our algorithm to reconstruct graphs without induced cycles of length at least $ k $ using $ o _ { \ delta, k } ( n \ log n ) $ queries. our lower bound is therefore tight for a wide range of tree - like graphs, such as chordal graphs, permutation graphs and at - free graphs. the previously best randomised algorithm for chordal graphs used $ o _ { \ delta } ( n \ log ^ 2 n ) $ queries in expectation, so we improve by a $ ( \ log n ) $ - factor for this graph class.
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arxiv:2306.05979
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the space mission microscope dedicated to the test of the equivalence principle ( ep ) operated from april 25, 2016 until the deactivation of the satellite on october 16, 2018. in this analysis we compare the free - fall accelerations ( $ a _ { \ rm a } $ and $ a _ { \ rm b } $ ) of two test masses in terms of the e \ " otv \ " os parameter $ \ eta ( { \ rm { a, b } } ) = 2 \ frac { a _ { \ rm a } - a _ { \ rm b } } { a _ { \ rm a } + a _ { \ rm b } } $. no ep violation has been detected for two test masses, made from platinum and titanium alloys, in a sequence of 19 segments lasting from 13 to 198 hours down to the limit of the statistical error which is smaller than $ 10 ^ { - 14 } $ for $ \ eta ( { \ rm { ti, pt } } ) $. accumulating data from all segments leads to $ \ eta ( { \ rm { ti, pt } } ) = [ - 1. 5 \ pm { } 2. 3 { \ rm ( stat ) } \ pm { } 1. 5 { \ rm ( syst ) } ] \ times { } 10 ^ { - 15 } $ showing no ep violation at the level of $ 2. 7 \ times { } 10 ^ { - 15 } $ if we combine stochastic and systematic errors quadratically. this represents an improvement of almost two orders of magnitude with respect to the previous best such test performed by the e \ " ot - wash group. the reliability of this limit has been verified by comparing the free falls of two test masses of the same composition ( platinum ) leading to a null e \ " otv \ " os parameter with a statistical uncertainty of $ 1. 1 \ times { } 10 ^ { - 15 } $.
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arxiv:2209.15488
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we present a time - dependent formulation of coupled cluster theory. this theory allows for direct computation of the free energy of quantum systems at finite temperature by imaginary time integration and is closely related to the thermal cluster cumulant theory of mukherjee and co - workers. our derivation highlights the connection to perturbation theory and zero - temperature coupled cluster theory. we show explicitly how the finite - temperature coupled cluster singles and doubles amplitude equations can be derived in analogy with the zero - temperature theory and how response properties can be efficiently computed using a variational lagrangian. we discuss the implementation for realistic systems and showcase the potential utility of the method with calculations of the exchange correlation energy of the uniform electron gas at warm dense matter conditions.
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arxiv:1807.09961
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the information bottleneck principle is an elegant and useful approach to representation learning. in this paper, we investigate the problem of representation learning in the context of reinforcement learning using the information bottleneck framework, aiming at improving the sample efficiency of the learning algorithms. % by accelerating the process of discarding irrelevant information when the % input states are extremely high - dimensional. we analytically derive the optimal conditional distribution of the representation, and provide a variational lower bound. then, we maximize this lower bound with the stein variational ( sv ) gradient method. we incorporate this framework in the advantageous actor critic algorithm ( a2c ) and the proximal policy optimization algorithm ( ppo ). our experimental results show that our framework can improve the sample efficiency of vanilla a2c and ppo significantly. finally, we study the information bottleneck ( ib ) perspective in deep rl with the algorithm called mutual information neural estimation ( mine ). we experimentally verify that the information extraction - compression process also exists in deep rl and our framework is capable of accelerating this process. we also analyze the relationship between mine and our method, through this relationship, we theoretically derive an algorithm to optimize our ib framework without constructing the lower bound.
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arxiv:1911.05695
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the electronic, laser - induced fluorescence spectrum of the $ b ^ 2 \ sigma ^ + \ leftarrow x ^ 2 \ sigma ^ + $ transition in $ ^ { 28 } $ si $ ^ { 16 } $ o $ ^ + $ and $ ^ { 29 } $ si $ ^ { 16 } $ o $ ^ + $ has been recorded in a cryogenic buffer gas cell at $ \ approx $ 100 k. molecular constants are extracted for both $ ^ { 28 } $ si $ ^ { 16 } $ o $ ^ + $ and $ ^ { 29 } $ si $ ^ { 16 } $ o $ ^ + $, including the fermi contact hyperfine constant for both the $ b $ and $ x $ states of $ ^ { 29 } $ si $ ^ { 16 } $ o $ ^ + $, and used in a discussion of the suitability of sio $ ^ + $ in future quantum information experiments.
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arxiv:2111.03832
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hexagonal boron nitride ( hbn ) has emerged as a promising ultrathin host of single photon emitters ( spes ) with favorable quantum properties at room temperature, making it a highly desirable element for integrated quantum photonic networks. one major challenge of using these spes in such applications is their low quantum efficiency. recent studies have reported an improvement in quantum efficiency by up to two orders of magnitude when integrating an ensemble of emitters such as boron vacancy defects in multilayered hbn flakes embedded within metallic nanocavities. however, these experiments have not been extended to spes and are mainly focused on multiphoton effects. here, we study the quantum single photon properties of hybrid nanophotonic structures composed of spes created in ultrathin hbn flakes coupled with plasmonic silver nanocubes. we demonstrate > 200 % plasmonic enhancement of the spe properties, manifested by a strong increase in the spe fluorescence. such enhancement is explained by rigorous numerical simulations where the hbn flake is in direct contact with the ag nanocubes that cause the plasmonic effects. the presented strong and fast single photon emission obtained at room - temperature with a compact hybrid nanophotonic platform can be very useful to various emerging applications in quantum optical communications and computing.
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arxiv:2304.00314
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we show and give the linear differential operators $ { \ cal l } ^ { scal } _ q $ of order q = n ^ 2 / 4 + n + 7 / 8 + ( - 1 ) ^ n / 8, for the integrals $ i _ n ( r ) $ which appear in the two - point correlation scaling function of ising model $ f _ { \ pm } ( r ) = \ lim _ { scaling } { \ cal m } _ { \ pm } ^ { - 2 } < \ sigma _ { 0, 0 } \, \ sigma _ { m, n } > = \ sum _ { n } i _ { n } ( r ) $. the integrals $ i _ { n } ( r ) $ are given in expansion around r = 0 in the basis of the formal solutions of $ \, { \ cal l } ^ { scal } _ q $ with transcendental combination coefficients. we find that the expression $ r ^ { 1 / 4 } \, \ exp ( r ^ 2 / 8 ) $ is a solution of the painlev \ ' e vi equation in the scaling limit. combinations of the ( analytic at $ r = 0 $ ) solutions of $ { \ cal l } ^ { scal } _ q $ sum to $ \ exp ( r ^ 2 / 8 ) $. we show that the expression $ r ^ { 1 / 4 } \ exp ( r ^ 2 / 8 ) $ is the scaling limit of the correlation function $ c ( n, n ) $ and $ c ( n, n + 1 ) $. the differential galois groups of the factors occurring in the operators $ { \ cal l } ^ { scal } _ q $ are given.
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arxiv:1410.6927
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near - lossless image compression - decompression scheme is proposed in this paper using zipper transformation ( zt ) and inverse zipper transformation ( izt ). the proposed zt exploits the conjugate symmetry property of discrete fourier transformation ( dft ). the proposed transformation is implemented using two different configurations : the interlacing and concatenating zt. in order to quantify the efficacy of the proposed transformation, we benchmark with discrete cosine transformation ( dct ) and fast walsh hadamard transformation ( fwht ) in terms of lossless compression capability and computational cost. numerical simulations show that zt - based compression algorithm is near - lossless, compresses better, and offers faster implementation than both dct and fwht. also, interlacing and concatenating zt are shown to yield similar results in most of the test cases considered.
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arxiv:1710.02907
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a dual - regge model with a nonlinear proton regge trajectory in the missing mass channel, describing the experimental data on low - mass single diffraction dissociation, is constructed. predictions for the lhc energies are given.
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arxiv:1011.0664
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we construct a purely frame - like parent action that allows to dualise, at the off - shell level, an arbitrary mixed - symmetry bosonic massless fields in minkowski background of dimensions d. starting from any massless mixed - symmetry gauge field in the standard skvortsov frame - like formulation and following an off - shell dualisation procedure, we obtain dual theories which are on - shell related by so ( d - 2 ) hodge duality. the hodge dualisation can be done on any column of the young diagram characterizing the generalised spin of the original frame - like field. dualisation with respect to the first column of the young diagram leads to a standard frame - like action for the dual field. any other dualisation results in an action which cannot be described by the standard frame - like formalism, as the on - shell field is not so ( d - 2 ) traceless. instead, the latter field is given by the product of an irreducible traceless tensor and a certain number of so ( d - 2 ) - invariant metrics, and the corresponding dual frame - like action is new. such actions require supplementary fields, which naturally arise along the lines of the approach that we propose.
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arxiv:1206.2052
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since their discovery, submillimetre - selected galaxies ( smgs ) have revolutionized the field of galaxy formation and evolution. from the hundreds of square degrees mapped at submillimetre wavelengths, only a handful of sources have been confirmed to lie at z > 5 and only two at z > 6. all of these smgs are rare examples of extreme starburst galaxies with star formation rates ( sfrs ) of > 1000 m _ sun / yr and therefore are not representative of the general population of dusty star - forming galaxies. consequently, our understanding of the nature of these sources, at the earliest epochs, is still incomplete. here we report the spectroscopic identification of a gravitationally amplified ( mu = 9. 3 + / - 1. 0 ) dusty star - forming galaxy at z = 6. 027. after correcting for gravitational lensing, we derive an intrinsic less - extreme sfr of 380 + / - 50 m _ sun / yr for this source and find that its gas and dust properties are similar to those measured for local ultra luminous infrared galaxies ( ulirgs ), extending the local trends to a poorly explored territory in the early universe. the star - formation efficiency of this galaxy is similar to those measured in its local analogues, despite a ~ 12 gyr difference in cosmic time.
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arxiv:1707.09022
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we give an interpretation of holography in the form of the ads / cft correspondence in terms of homotopy algebras. a field theory such as a bulk gravity theory can be viewed as a homotopy lie or $ l _ { \ infty } $ algebra. we extend this dictionary to theories defined on manifolds with a boundary, including the conformal boundary of ads, taking into account the cyclic structure needed to define an action with the correct boundary terms. projecting fields to their boundary values then defines a homotopy retract, which in turn implies that the cyclic $ l _ { \ infty } $ algebra of the bulk theory is equivalent, up to homotopy, to a cyclic $ l _ { \ infty } $ algebra on the boundary. the resulting action is the ` on - shell action ' conventionally computed via witten diagrams that, according to ads / cft, yields the generating functional for the correlation functions of the dual cft. these results are established with the help of new techniques regarding the homotopy transfer of cyclic $ l _ { \ infty } $ algebras.
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arxiv:2307.08094
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perception - related errors comprise most diagnostic mistakes in radiology. to mitigate this problem, radiologists employ personalized and high - dimensional visual search strategies, otherwise known as search patterns. qualitative descriptions of these search patterns, which involve the physician verbalizing or annotating the order he / she analyzes the image, can be unreliable due to discrepancies in what is reported versus the actual visual patterns. this discrepancy can interfere with quality improvement interventions and negatively impact patient care. this study presents a novel discretized feature encoding based on spatiotemporal binning of fixation data for efficient geometric alignment and temporal ordering of eye movement when reading chest x - rays. the encoded features of the eye - fixation data are employed by machine learning classifiers to discriminate between faculty and trainee radiologists. we include a clinical trial case study utilizing the area under the curve ( auc ), accuracy, f1, sensitivity, and specificity metrics for class separability to evaluate the discriminability between the two subjects in regard to their level of experience. we then compare the classification performance to state - of - the - art methodologies. a repeatability experiment using a separate dataset, experimental protocol, and eye tracker was also performed using eight subjects to evaluate the robustness of the proposed approach. the numerical results from both experiments demonstrate that classifiers employing the proposed feature encoding methods outperform the current state - of - the - art in differentiating between radiologists in terms of experience level. this signifies the potential impact of the proposed method for identifying radiologists ' level of expertise and those who would benefit from additional training.
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arxiv:2308.02748
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we consider an extension of the standard model with three right - handed ( rh ) neutrinos and a dirac pair of extra sterile neutrinos, odd under a discrete $ z _ 2 $ symmetry, in order to have left - right symmetry in the neutrino content and obtain tiny neutrino masses from the latter ones only. our working hypothesis is that the heavy rh neutrinos do not influence phenomenology at low energies. we use the usual high - scale seesaw to suppress all of the mass terms involving rh neutrinos and a low - scale minimal variant of the linear seesaw led by the dirac mass of the extra sterile neutrinos to provide the small mass of active neutrinos. one of the active neutrinos is massless, which fixes the mass of the other two on the basis of a soft breaking of the $ z _ 2 $ symmetry. the mixing between the extra neutrinos makes for a particle that effectively behaves like a dirac sterile neutrino with mass around the gev level.
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arxiv:2107.14726
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we adopted an approach based on an lstm neural network to monitor and detect faults in industrial multivariate time series data. to validate the approach we created a modelica model of part of a real gasoil plant. by introducing hacks into the logic of the modelica model, we were able to generate both the roots and causes of fault behavior in the plant. having a self - consistent data set with labeled faults, we used an lstm architecture with a forecasting error threshold to obtain precision and recall quality metrics. the dependency of the quality metric on the threshold level is considered. an appropriate mechanism such as " one handle " was introduced for filtering faults that are outside of the plant operator field of interest.
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arxiv:1612.06676
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development and interaction of starting vortices initiated by dielectric barrier discharge ( dbd ) plasma actuators in quiescent air are illustrated in the attached fluid dynamics videos. these include a series of smoke flow visualisations, showing the starting vortices moving parallel or normal to the wall at several different actuator configurations.
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arxiv:0909.4941
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the neoclassical causal version for newton ' s acausal gravitational theory explains exactly the anomalous speed - changes observed for six earth flybys and an anomalous lunar orbital speed - change ( arxiv : 1105. 3857v10 ). this article estimates the effects of the neoclassical causal theory on the orbital motions of two objects revolving around the sun, mercury and halley ' s comet. the change in the period for mercury is predicted to be about + 1. 86 ms per year, and the predicted change in the angle for perihelion is - 0. 032 arc seconds per century, for which the magnitude is negligible compared with the relativistic advance of + 43 arc seconds per century. the period for halley ' s comet, 75. 3 years, is predicted to decrease by about 10 minutes. therefore, the neoclassical causal theory does not conflict with general relativity theory, and it is not the cause for a delay of one or two weeks in the return time of halley ' s comet.
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arxiv:1201.0965
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to understand cosmic mass assembly in the universe at early epochs, we primarily rely on measurements of stellar mass and star formation rate of distant galaxies. in this paper, we present stellar masses and star formation rates of six high - redshift ( $ 2. 8 \ leq z \ leq 5. 7 $ ) dusty, star - forming galaxies ( dsfgs ) that are strongly gravitationally lensed by foreground galaxies. these sources were first discovered by the south pole telescope ( spt ) at millimeter wavelengths and all have spectroscopic redshifts and robust lens models derived from alma observations. we have conducted follow - up observations, obtaining multi - wavelength imaging data, using { \ it hst }, { \ it spitzer }, { \ it herschel } and the atacama pathfinder experiment ( apex ). we use the high - resolution { \ it hst } / wfc3 images to disentangle the background source from the foreground lens in { \ it spitzer } / irac data. the detections and upper limits provide important constraints on the spectral energy distributions ( seds ) for these dsfgs, yielding stellar masses, ir luminosities, and star formation rates ( sfrs ). the sed fits of six spt sources show that the intrinsic stellar masses span a range more than one order of magnitude with a median value $ \ sim $ 5 $ \ times 10 ^ { 10 } m _ { \ sun } $. the intrinsic ir luminosities range from 4 $ \ times 10 ^ { 12 } l _ { \ sun } $ to 4 $ \ times 10 ^ { 13 } l _ { \ sun } $. they all have prodigious intrinsic star formation rates of 510 to 4800 $ m _ { \ sun } { \ rm yr } ^ { - 1 } $. compared to the star - forming main sequence ( ms ), these six dsfgs have specific sfrs that all lie above the ms, including two galaxies that are a factor of 10 higher than the ms. our results suggest that we are witnessing the ongoing strong starburst events which may be driven by major mergers.
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arxiv:1509.02835
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in a 1986 paper, smyth proposed a conjecture about which integer - linear relations were possible among galois - conjugate algebraic numbers. we prove this conjecture. the main tools ( as smyth already anticipated ) are combinatorial rather than number - theoretic in nature. for instance, the question can be reinterpreted as a question about the possible eigenvalues of a specified linear combination of permutation matrices. what ' s more, we reinterpret smyth ' s conjecture as a local - to - global principle for a " non - deterministic system of equations " where variables are interpreted as compactly supported k - valued random variables ( for k a local or global field ) rather than as elements of k.
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arxiv:2503.15833
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central regions of the early - type disk galaxies ngc 524 and ngc 6340 have been investigated with the multi - pupil field spectrograph at the 6m telescope of the special astrophysical observatory of the russian academy of sciences. i confirm the existence of chemically distinct stellar nuclei in these galaxies which have been claimed earlier. the metallicity differences which are found between the nuclei and the bulges, 0. 5 - 1. 0 kpc from the centers, reach 0. 5 - 0. 6 dex. both nuclei are magnesium overabundant, but the bulges have different magnesium - to - iron ratios : it is solar in ngc 6340 and the same as the nuclear one in ngc 524. the kinematical and morphological analyses reveal the existence of inclined central disks in these galaxies. in ngc 524 the central disk consists of stars, dust, and ionized gas ; its extension may be as large as up to r = 3 kpc, and it is inclined by more than 20 deg to the global galactic plane. in ngc 6340 only a gaseous polar disk with the radius less than 500 pc is detected.
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arxiv:astro-ph/0007051
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we derive an action describing edge dynamics on interfaces for gauge theories ( maxwell and yang - mills ) using the path integral. the canonical structure of the edge theory is deduced and the thermal partition function calculated. we test the edge action in several applications. for maxwell in rindler space, we recover earlier results, now embedded in a dynamical canonical framework. a second application is 2d yang - mills theory where the boundary action becomes just the particle - on - a - group action. correlators of boundary - anchored wilson lines in 2d yang - mills are matched with, and identified as correlators of bilocal operators in the particle - on - a - group edge model.
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arxiv:1804.07585
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in this talk, i will explain how to reduce the spectral index to be n _ s = 0. 96 for supernatural inflation. i will also show the constraint to the reheating temperature from big bang nucleosynthesis of both thermal and non - thermal gravitino production.
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arxiv:1012.2647
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we present the gpu calculation with the common unified device architecture ( cuda ) for the wolff single - cluster algorithm of the ising model. proposing an algorithm for a quasi - block synchronization, we realize the wolff single - cluster monte carlo simulation with cuda. we perform parallel computations for the newly added spins in the growing cluster. as a result, the gpu calculation speed for the two - dimensional ising model at the critical temperature with the linear size l = 4096 is 5. 60 times as fast as the calculation speed on a current cpu core. for the three - dimensional ising model with the linear size l = 256, the gpu calculation speed is 7. 90 times as fast as the cpu calculation speed. the idea of quasi - block synchronization can be used not only in the cluster algorithm but also in many fields where the synchronization of all threads is required.
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arxiv:1110.0899
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lens models appropriate for representing cusped galaxies and clusters are developed. the analogue of the odd number theorem for cusped density distributions is given. density cusps are classified into strong, isothermal or weak, according to their lensing properties. strong cusps cause multiple imaging for any source position, whereas isothermal and weak cusps give rise to only one image for distant sources. isothermal cusps always possess a pseudo - caustic. when the source crosses the pseudo - caustic, the number of images changes by unity. two families of cusped galaxy and cluster models are examined in detail. the double power - law family has an inner cusp, followed by a transition region and an outer envelope. one member of this family - - the isothermal double power - law model - - possesses an exceedingly scarce property, namely, the lens equation is exactly solvable for any source position. this means that the magnifications, the time delay and the lensing cross - sections are all readily available. the model has a three dimensional density that is cusped like $ r ^ { - 2 } $ at small radii and falls off like $ r ^ { - 4 } $ asymptotically. thus, it provides a very useful representation of the lensing properties of a galaxy or cluster of finite total mass with a flat rotation curve. the second set of models studied is the single power - law family. these are single density cusps of infinite extent. the properties of the critical curves and caustics and the behaviour of the lenses in the presence of external shear are all discussed in some detail.
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arxiv:astro-ph/9712087
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cooperatively avoiding collision is a critical functionality for robots navigating in dense human crowds, failure of which could lead to either overaggressive or overcautious behavior. a necessary condition for cooperative collision avoidance is to couple the prediction of the agents ' trajectories with the planning of the robot ' s trajectory. however, it is unclear that trajectory based cooperative collision avoidance captures the correct agent attributes. in this work we migrate from trajectory based coupling to a formalism that couples agent preference distributions. in particular, we show that preference distributions ( probability density functions representing agents ' intentions ) can capture higher order statistics of agent behaviors, such as willingness to cooperate. thus, coupling in distribution space exploits more information about inter - agent cooperation than coupling in trajectory space. we thus introduce a general objective for coupled prediction and planning in distribution space, and propose an iterative best response optimization method based on variational analysis with guaranteed sufficient decrease. based on this analysis, we develop a sampling - based motion planning framework called distnav that runs in real time on a laptop cpu. we evaluate our approach on challenging scenarios from both real world datasets and simulation environments, and benchmark against a wide variety of model based and machine learning based approaches. the safety and efficiency statistics of our approach outperform all other models. finally, we find that distnav is competitive with human safety and efficiency performance.
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arxiv:2106.13667
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a critical barrier to learning an accurate decision rule for outlier detection is the scarcity of outlier data. as such, practitioners often turn to the use of similar but imperfect outlier data from which they might transfer information to the target outlier detection task. despite the recent empirical success of transfer learning approaches in outlier detection, a fundamental understanding of when and how knowledge can be transferred from a source to a target outlier detection task remains elusive. in this work, we adopt the traditional framework of neyman - pearson classification - - which formalizes supervised outlier detection - - with the added assumption that one has access to some related but imperfect outlier data. our main results are as follows : we first determine the information - theoretic limits of the problem under a measure of discrepancy that extends some existing notions from traditional balanced classification ; interestingly, unlike in balanced classification, seemingly very dissimilar sources can provide much information about a target, thus resulting in fast transfer. we then show that, in principle, these information - theoretic limits are achievable by adaptive procedures, i. e., procedures with no a priori information on the discrepancy between source and target outlier distributions.
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arxiv:2310.04686
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in this paper we study perturbed ornstein - uhlenbeck operators \ begin { align * } [ \ mathcal { l } _ { \ infty } v ] ( x ) = a \ triangle v ( x ) + \ langle sx, \ nabla v ( x ) \ rangle - b v ( x ), \, x \ in \ mathbb { r } ^ d, \, d \ geqslant 2, \ end { align * } for simultaneously diagonalizable matrices $ a, b \ in \ mathbb { c } ^ { n, n } $. the unbounded drift term is defined by a skew - symmetric matrix $ s \ in \ mathbb { r } ^ { d, d } $. differential operators of this form appear when investigating rotating waves in time - dependent reaction diffusion systems. we prove under certain conditions that the maximal domain $ \ mathcal { d } ( a _ p ) $ of the generator $ a _ p $ belonging to the ornstein - uhlenbeck semigroup coincides with the domain of $ \ mathcal { l } _ { \ infty } $ in $ l ^ p ( \ mathbb { r } ^ d, \ mathbb { c } ^ n ) $ given by \ begin { align * } \ mathcal { d } ^ p _ { \ mathrm { loc } } ( \ mathcal { l } _ 0 ) = \ left \ { v \ in w ^ { 2, p } _ { \ mathrm { loc } } \ cap l ^ p \ mid a \ triangle v + \ langle s \ cdot, \ nabla v \ rangle \ in l ^ p \ right \ }, \, 1 < p < \ infty. \ end { align * } one key assumption is a new $ l ^ p $ - antieigenvalue condition \ begin { align * } \ mu _ 1 ( a ) > \ frac { | p - 2 | } { p }, \, 1 < p < \ infty, \, \ mu _ 1 ( a ) \ text { first antieigenvalue of $ a $. } \ end { align * } the proof utilizes the following ingredients. first we show the closedness of $ \ mathcal { l } _ { \ infty } $ in $ l ^ p $ and derive $ l ^ p $ - resolve
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arxiv:1510.00827
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many non - locally compact second countable groups admit a comeagre conjugacy class. for example, this is the case for the automorphism group of the rational order and the automorphism group of the random graph [ truss ]. a. kechris and c. rosendal ask if a non - trivial locally compact second countable group can admit a comeagre conjugacy class. we answer the question in the negative via an analysis of locally compact second countable groups with topological conditions on a conjugacy class.
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arxiv:1310.1561
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in this paper we generalize the notion of discriminant for symmetric matrices and some results about it to the case of symmetric spaces.
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arxiv:2107.08081
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recent observations suggest that abundance pattern differences exist between low metallicity stars in the milky way stellar halo and those in the dwarf satellite galaxies. this paper takes a first look at what role the early environment for pre - galactic star formation might have played in shaping these stellar populations. in particular, we consider whether differences in cross - pollution between the progenitors of the stellar halo and the satellites could help to explain the differences in abundance patterns. using an n - body simulation, we find that the progenitor halos of the main halo are primarily clustered together at z = 10 while the progenitors of the satellite galaxies remain on the outskirts of this cluster. next, analytically modeled supernova - driven winds show that main halo progenitors cross - pollute each other more effectively while satellite galaxy progenitors remain more isolated. thus, inhomogeneous cross - pollution as a result of different high - z spatial locations of each system ' s progenitors can help to explain observed differences in abundance patterns today. conversely, these differences are a signature of the inhomogeneity of metal enrichment at early times.
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arxiv:1306.5239
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in this paper we develop the theory of quantum reverse hypercontractivity inequalities and show how they can be derived from log - sobolev inequalities. next we prove a generalization of the stroock - varopoulos inequality in the non - commutative setting which allows us to derive quantum hypercontractivity and reverse hypercontractivity inequalities solely from $ 2 $ - log - sobolev and $ 1 $ - log - sobolev inequalities respectively. we then prove some tensorization - type results providing us with tools to prove hypercontractivity and reverse hypercontractivity not only for certain quantum superoperators but also for their tensor powers. finally as an application of these results, we generalize a recent technique for proving strong converse bounds in information theory via reverse hypercontractivity inequalities to the quantum setting. we prove strong converse bounds for the problems of quantum hypothesis testing and classical - quantum channel coding based on the quantum reverse hypercontractivity inequalities that we derive.
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arxiv:1804.10100
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we propose a method to design a decentralized energy market which guarantees individual rationality ( ir ) in expectation, in the presence of system - level grid constraints. we formulate the market as a welfare maximization problem subject to ir constraints, and we make use of lagrangian duality to model the problem as a n - person non - cooperative game with a unique generalized nash equilibrium ( gne ). we provide a distributed algorithm which converges to the gne. the convergence and properties of the algorithm are investigated by means of numerical simulations.
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arxiv:1806.01072
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we consider the straggler problem in decentralized learning over a logical ring while preserving user data privacy. especially, we extend the recently proposed framework of differential privacy ( dp ) amplification by decentralization by cyffers and bellet to include overall training latency - - comprising both computation and communication latency. analytical results on both the convergence speed and the dp level are derived for both a skipping scheme ( which ignores the stragglers after a timeout ) and a baseline scheme that waits for each node to finish before the training continues. a trade - off between overall training latency, accuracy, and privacy, parameterized by the timeout of the skipping scheme, is identified and empirically validated for logistic regression on a real - world dataset and for image classification using the mnist and cifar - 10 datasets.
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arxiv:2212.03080
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engineering methods are centered around traditional notions of decomposition and recomposition that rely on partitioning the inputs and outputs of components to allow for component - level properties to hold after their composition. in artificial intelligence ( ai ), however, systems are often expected to influence their environments, and, by way of their environments, to influence themselves. thus, it is unclear if an ai system ' s inputs will be independent of its outputs, and, therefore, if ai systems can be treated as traditional components. this paper posits that engineering general intelligence requires new general systems precepts, termed the core and periphery, and explores their theoretical uses. the new precepts are elaborated using abstract systems theory and the law of requisite variety. by using the presented material, engineers can better understand the general character of regulating the outcomes of ai to achieve stakeholder needs and how the general systems nature of embodiment challenges traditional engineering practice.
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arxiv:2208.02837
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these proceedings summarize the lhcb measurements of charm - and beauty - hadron production in ppb collisions. the studies are made down to very low - \ pt of the observed heavy - flavor hadrons using fully reconstructed decays. nuclear matter effects are quantified via nuclear modification factors and forward - backward production ratios. a strong suppression is observed at positive rapidity ( proton beam direction ), while a modest or no suppression is seen for the backward rapidity ( lead beam direction ). the nuclear parton distributions of the lead nucleus is constrained down to bjorken - $ x \ sim10 ^ { - 5 } $, assuming it is the only nuclear effect for open heavy - flavor production. these data provide important inputs to understand the quark - gluon plasma formed in heavy - nucleus collisions.
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arxiv:1902.03788
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the coherent reaction, $ \ gamma d \ rightarrow \ pi ^ 0 \ eta d $ was studied with the bgood experiment at elsa from threshold to a centre - of - mass energy of 3200 \, mev. a full kinematic reconstruction was made, with final state deuterons identified in the forward spectrometer and $ \ pi ^ 0 $ and $ \ eta $ decays in the central bgo rugby ball. the strength of the differential cross section exceeds what can be described by models of coherent photoproduction at forward angles by orders of magnitude. the distribution of the differential cross section has an excellent agreement with a model including quasi - free $ \ delta \ pi $ photoproduction, pion re - scattering and $ n ( 1535 ) $ formation and subsequent nucleon coalescence to the deuteron. this also gives a reasonable description of the two - body invariant mass distributions and naturally explains the similar magnitudes of this channel and $ \ pi ^ 0 \ pi ^ 0 d $ coherent photoproduction.
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arxiv:2405.09392
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we report an extremely tight, linear relation between $ { \ rm h \ alpha } $ and [ o iii ] line fluxes in logarithm, discovered using a large sample of low and mid - resolution spectra ( totaling 563 ) obtained by the james webb space telescope ( jwst ) nirspec instrument in three widely separated extragalactic fields. while a certain correlation between $ { \ rm h \ alpha } $ and [ o iii ] is expected for star forming galaxies, such a log - linear and tight ( dispersion of $ \ sim $ 0. 1 dex ) and trend is hard to explain because dust reddening would skew any intrinsic relation between the two. furthermore, another surprising finding emerges from investigating the dust reddening properties of these galaxies. we find that the classic method of using the balmer decrements under the standard case b assumption does not work : a high fraction ( $ \ sim $ 40 \ % ) of our objects have $ { \ rm h \ alpha } $ / $ { \ rm h \ beta } $ line ratios even smaller than the canonical case b ratio of 2. 86. such a high fraction of non - case b balmer decrements is also present in other jwst and ground - based spectroscopic studies, but the universal applicability of the case b assumption was not questioned until recently. the mysterious $ { \ rm h \ alpha } $ - - [ o iii ] correlation and the high fraction of non - case b balmer decrements, which may or may not be related, should be further investigated to put our spectral analysis onto a more solid footing.
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arxiv:2503.21896
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within the quantum field theory context the idea of a " cosmological constant " ( cc ) evolving with time looks quite natural as it just reflects the change of the vacuum energy with the typical energy of the universe. in the particular frame of ref. [ 30 ], a " running cc " at low energies may arise from generic quantum effects near the planck scale, m _ p, provided there is a smooth decoupling of all massive particles below m _ p. in this work we further develop the cosmological consequences of a " running cc " by addressing the accelerated evolution of the universe within that model. the rate of change of the cc stays slow, without fine - tuning, and is comparable to h ^ 2 m _ p ^ 2. it can be described by a single parameter, \ nu, that can be determined from already planned experiments using sne ia at high z. the range of allowed values for \ nu follow mainly from nucleosynthesis restrictions. present samples of sne ia can not yet distinguish between a " constant " cc or a " running " one. the numerical simulations presented in this work show that snap can probe the predicted variation of the cc either ruling out this idea or confirming the evolution hereafter expected.
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arxiv:hep-ph/0311171
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we provide analytical $ o ( \ alpha _ s ) $ results for the three polarized decay structure functions $ h _ { + + }, \, h _ { 00 } $ and $ h _ { - - } $ that describe the decay of a polarized $ w $ boson into massive quark - - antiquark pairs. as an application we consider the decay $ t \ to b + w ^ + $ involving the helicity fractions $ \ rho _ { mm } $ of the $ w ^ + $ boson followed by the polarized decay $ \ hbox { $ w ^ + ( \ uparrow ) $ } \ to q _ 1 \ bar { q } _ 2 $ described by the polarized decay structure functions $ h _ { mm } $. we thereby determine the $ o ( \ alpha _ s ) $ polar angle decay distribution of the cascade decay process $ t \ to b + w ^ + ( \ to q _ 1 \ bar { q } _ 2 ) $. as a second example we analyze quark mass and off - shell effects in the cascade decays $ h \ to w ^ { - } + w ^ { \ ast + } ( \ to q _ 1 \ bar { q } _ 2 ) $ and $ h \ to z + z ^ { \ ast } ( \ to q \ bar { q } ) $. for the decays $ h \ to w ^ { - } + w ^ { \ ast + } ( \ to c \ bar b ) $ and $ h \ to z + z ^ { \ ast } ( \ to b \ bar { b } ) $ we find substantial deviations from the mass - zero approximation in particular in the vicinity of the threshold region.
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arxiv:1301.0881
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the notion of hopf center and hopf cocenter of a hopf algebra is investigated by the extension theory of hopf algebras. we prove that each of them yields an exact sequence of hopf algebras. moreover the exact sequences are shown to satisfy the faithful ( co ) flatness condition. hopf center and cocenter are computed for $ \ mathsf { u } _ q ( \ mathfrak { g } ) $ and the hopf algebra $ \ textrm { pol } ( \ mathbb { g } _ q ) $, where $ \ mathbb { g } _ q $ is the drinfeld - jimbo quantization of a compact semisimple simply connected lie group $ \ mathbb { g } $ and $ \ mathfrak { g } $ is a simple complex lie algebra.
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arxiv:1512.03749
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this paper presents the use of panoramic 3d estimation in lighting simulation. conventional lighting simulation necessitates detailed modeling as input, resulting in significant labor effort and time cost. the 3d layout estimation method directly takes a single panorama as input and generates a lighting simulation model with room geometry and window aperture. we evaluate the simulation results by comparing the luminance errors between on - site high dynamic range ( hdr ) photographs, 3d estimation model, and detailed model in panoramic representation and fisheye perspective. given the selected scene, the results demonstrate the estimated room layout is reliable for lighting simulation.
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arxiv:2403.14836
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we throw a brief glance at galois ' life, on the occasion of his 200th anniversary ( written in german ).
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arxiv:1110.5412
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fizeau experiment, inspiring einstein ' s special theory of relativity, reveals a small dragging effect of light inside a moving medium. dispersion can enhance such light drag according to lorentz ' s predication. here we experimentally demonstrate slow and fast light enhanced light drag in a moving optical microcavity through stimulated brillouin scattering induced transparency and absorption. the strong dispersion provides an enhancement factor up to ~ 10 ^ 4, greatly reducing the system size down to the micrometer range. these results may offer a unique platform for a compact, integrated solution to motion sensing and ultrafast signal processing applications.
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arxiv:1905.07736
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we consider the $ k $ - clustering problem with $ \ ell _ p $ - norm cost, which includes $ k $ - median, $ k $ - means and $ k $ - center, under an individual notion of fairness proposed by jung et al. [ 2020 ] : given a set of points $ p $ of size $ n $, a set of $ k $ centers induces a fair clustering if every point in $ p $ has a center among its $ n / k $ closest neighbors. mahabadi and vakilian [ 2020 ] presented a $ ( p ^ { o ( p ) }, 7 ) $ - bicriteria approximation for fair clustering with $ \ ell _ p $ - norm cost : every point finds a center within distance at most $ 7 $ times its distance to its $ ( n / k ) $ - th closest neighbor and the $ \ ell _ p $ - norm cost of the solution is at most $ p ^ { o ( p ) } $ times the cost of an optimal fair solution. in this work, for any $ \ varepsilon > 0 $, we present an improved $ ( 16 ^ p + \ varepsilon, 3 ) $ - bicriteria for this problem. moreover, for $ p = 1 $ ( $ k $ - median ) and $ p = \ infty $ ( $ k $ - center ), we present improved cost - approximation factors $ 7. 081 + \ varepsilon $ and $ 3 + \ varepsilon $ respectively. to achieve our guarantees, we extend the framework of [ charikar et al., 2002, swamy, 2016 ] and devise a $ 16 ^ p $ - approximation algorithm for the facility location with $ \ ell _ p $ - norm cost under matroid constraint which might be of an independent interest. besides, our approach suggests a reduction from our individually fair clustering to a clustering with a group fairness requirement proposed by kleindessner et al. [ 2019 ], which is essentially the median matroid problem [ krishnaswamy et al., 2011 ].
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arxiv:2106.14043
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to a closed connected oriented surface $ s $ of genus $ g $ and a nonempty finite subset $ p $ of $ s $ is associated a simplicial complex ( the arc complex ) that plays a basic r \ ^ ole in understanding the mapping class group of the pair $ ( s, p ) $. it is known that this arc complex contains in a natural way the product of the teichm \ " uller space of $ ( s, p ) $ with an open simplex. in this paper we give an interpretation for the whole arc complex and prove that it is a quotient of a deligne - - mumford extension of this teichm \ " uller space and a closed simplex. we also describe a modification of the arc complex in the spirit of deligne - - mumford.
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arxiv:alg-geom/9412002
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of the many families of cryptographic schemes proposed to be post - quantum, a relatively unexplored set of examples comes from group - based cryptography. one of the more central schemes from this area is the so - called semidirect product key exchange ( sdpke ), a generalisation of diffie - hellman key exchange that is plausibly post - quantum. in this report we survey the state of the literature relating to sdpke, providing a high - level discussion of security, as well as a comprehensive overview of the proposed platforms and the main cryptanalytic ideas relevant to each.
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arxiv:2202.05178
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we present observations of class b2108 + 213, the widest separation gravitational lens system discovered by the cosmic lens all - sky survey. radio imaging using the vla at 8. 46 ghz and merlin at 5 ghz shows two compact components separated by 4. 56 arcsec with a faint third component in between which we believe is emission from a lensing galaxy. 5 - ghz vlba observations reveal milliarcsecond - scale structure in the two lensed images that is consistent with gravitational lensing. optical emission from the two lensed images and two lensing galaxies within the einstein radius is detected in hubble space telescope imaging. furthermore, an optical gravitational arc, associated with the strongest lensed component, has been detected. surrounding the system are a number of faint galaxies which may help explain the wide image separation. a plausible mass distribution model for class b2108 + 213 is also presented.
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arxiv:astro-ph/0410554
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covid - 19 has devastated the entire global community. vaccines present an opportunity to mitigate the pandemic ; however, the effect of vaccination coupled with the behavioral response of the population is not well understood. we propose a model that incorporates two important dynamically varying population behaviors : level of caution and sense of safety. level of caution increases with the number of infectious cases, while an increasing sense of safety with increased vaccination lowers precautionary behaviors. to the best of our knowledge, this is the first model that can effectively reproduce the complete time history of covid - 19 infections for various regions of the united states and provides relatable measures of dynamic changes in the population behavior and disease transmission rates. we propose a parameter d _ i as a direct measure of a population ' s caution against an infectious disease, that can be obtained from the ongoing new infectious cases. the model provides a method for quantitative measure of critical infectious disease attributes for a population including highest disease transmission rate, effective disease transmission rate, and disease related precautionary behavior. we predict future covid - 19 pandemic trends in the united states accounting for vaccine rollout and behavioral response. although a high rate of vaccination is critical to quickly end the pandemic, we find that a return towards pre - pandemic social behavior due to increased sense of safety during vaccine deployment, can cause an alarming surge in infections. our results indicate that at the current rate of vaccination, the new infection cases for covid - 19 in the united states will approach zero by the end of august 2021. the model can be used for predicting future epidemic and pandemic dynamics before and during vaccination.
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arxiv:2103.00677
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( e. g. phytochemistry, phytogeography ). the study of fossil plants is called palaeobotany. other fields are denoted by adding or substituting the word botany ( e. g. systematic botany ). phytosociology is a subfield of plant ecology that classifies and studies communities of plants. the intersection of fields from the above pair of categories gives rise to fields such as bryogeography, the study of the distribution of mosses. different parts of plants also give rise to their own subfields, including xylology, carpology ( or fructology ), and palynology, these being the study of wood, fruit and pollen / spores respectively. botany also overlaps on the one hand with agriculture, horticulture and silviculture, and on the other hand with medicine and pharmacology, giving rise to fields such as agronomy, horticultural botany, phytopathology, and phytopharmacology. = = scope and importance = = the study of plants is vital because they underpin almost all animal life on earth by generating a large proportion of the oxygen and food that provide humans and other organisms with aerobic respiration with the chemical energy they need to exist. plants, algae and cyanobacteria are the major groups of organisms that carry out photosynthesis, a process that uses the energy of sunlight to convert water and carbon dioxide into sugars that can be used both as a source of chemical energy and of organic molecules that are used in the structural components of cells. as a by - product of photosynthesis, plants release oxygen into the atmosphere, a gas that is required by nearly all living things to carry out cellular respiration. in addition, they are influential in the global carbon and water cycles and plant roots bind and stabilise soils, preventing soil erosion. plants are crucial to the future of human society as they provide food, oxygen, biochemicals, and products for people, as well as creating and preserving soil. historically, all living things were classified as either animals or plants and botany covered the study of all organisms not considered animals. botanists examine both the internal functions and processes within plant organelles, cells, tissues, whole plants, plant populations and plant communities. at each of these levels, a botanist may be concerned with the classification ( taxonomy ), phylogeny and evolution, structure ( anatomy and morphology ), or function ( physiology ) of plant life.
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https://en.wikipedia.org/wiki/Botany
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a new monte carlo code for the simulation of the channeling of ultrarelativistic charged projectiles in single crystals is presented. a detailed description of the underlying physical model and the computation algorithm is given. first results obtained with the code for the channeling of 855 mev electrons in silicon crystal are presented. the dechanneling lengths for ( 100 ), ( 110 ) and ( 111 ) crystallographic planes are estimated. in order to verify the code, the dependence of the intensity of the channeling radiation on the crystal dimension along the beam direction is calculated. a good agreement of the obtained results with recent experimental data is observed.
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arxiv:1008.1707
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gravity is nearly a universal constant in the cusp of an nfw galaxy halo. inside this external field an isothermal gas sphere will collapse and trigger a starburst if above a critical central pressure. thus formed spheroidal stellar systems have sersic - profile and satisfy the faber - jackson relation. the process is consistent with observed starbursts. we also recover the m _ bh vs. velocity dispersion relation, if the gas collapse is regulated or resisted by the feedback from radiation from the central bh.
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arxiv:0709.4496
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we propose an experimentally accessible single - photon routing scheme using a $ \ bigtriangleup $ - type three - level atom embedded in quantum multi - channels composed of coupled - resonator waveguides. via the on - demand classical field applied to the atom, the router can extract a single photon from the incident channel, and then redirect it into another. the efficient functions of perfect reflection of single photon signal in the incident channel is rooted in the coherent resonance and the existence of photonic bound states.
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arxiv:1303.3687
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moments of the quark density, helicity, and transversity distributions are calculated in unquenched lattice qcd. calculations of proton matrix elements of operators corresponding to these moments through the operator product expansion have been performed on $ 16 ^ 3 \ times 32 $ lattices for wilson fermions at $ \ beta = 5. 6 $ using configurations from the sesam collaboration and at $ \ beta = 5. 5 $ using configurations from scri. one - loop perturbative renormalization corrections are included. at quark masses accessible in present calculations, there is no statistically significant difference between quenched and full qcd results, indicating that the contributions of quark - antiquark excitations from the dirac sea are small. close agreement between calculations with cooled configurations containing essentially only instantons and the full gluon configurations indicates that quark zero modes associated with instantons play a dominant role. naive linear extrapolation of the full qcd calculation to the physical pion mass yields results inconsistent with experiment. extrapolation to the chiral limit including the physics of the pion cloud can resolve this discrepancy and the requirements for a definitive chiral extrapolation are described.
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arxiv:hep-lat/0201021
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this paper is motivated by the automation of neuropsychological tests involving discourse analysis in the retellings of narratives by patients with potential cognitive impairment. in this scenario the task of sentence boundary detection in speech transcripts is important as discourse analysis involves the application of natural language processing tools, such as taggers and parsers, which depend on the sentence as a processing unit. our aim in this paper is to verify which embedding induction method works best for the sentence boundary detection task, specifically whether it be those which were proposed to capture semantic, syntactic or morphological similarities.
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arxiv:1708.04704
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overfitting describes a machine learning phenomenon where the model fits too closely to the training data, resulting in poor generalization. while this occurrence is thoroughly documented for many forms of supervised learning, it is not well examined in the context of unsupervised learning. in this work we examine the nature of overfitting in unsupervised contrastive learning. we show that overfitting can indeed occur and the mechanism behind overfitting.
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arxiv:2407.15863
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the worldline variational approach is extended beyond the quenched approximation, i. e. to include virtual pair production of heavy particles. this is achieved either by an expansion of the functional determinant to second order or by an hybrid ansatz for the quadratic trial action consisting of fields for the light particles and worldlines for the heavy ones as in the linear polaron model. numerical results and analytic approximations show a reduction of radiative effects with increasing number of flavors.
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arxiv:hep-ph/0601088
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although multivariate stochastic volatility models usually produce more accurate forecasts compared to the mgarch models, their estimation techniques such as bayesian mcmc typically suffer from the curse of dimensionality. we propose a fast and efficient estimation approach for msv based on a penalized ols framework. specifying the msv model as a multivariate state space model, we carry out a two - step penalized procedure. we provide the asymptotic properties of the two - step estimator and the oracle property of the first - step estimator when the number of parameters diverges. the performances of our method are illustrated through simulations and financial data.
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arxiv:2201.08584
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dislocation structures, chemical segregation, { \ gamma ^ { \ prime }, { \ gamma ^ { \ prime \ prime } }, { \ delta } precipitates and laves phase were quantified within the microstructures of inconel 718 ( in718 ) produced by laser powder bed fusion additive manufacturing ( am ) and subjected to standard, direct aging, and modified multi - step heat treatments. additionally, heat - treated samples still attached to the build plates vs. those removed were also documented for a standard heat treatment. the effects of the different resulting microstructures on room temperature strengths and elongations to failure is revealed. knowledge derived from these process structure property relationships was used to engineer a super solvus solution anneal at 1020 degc for 15 minutes, followed by aging at 720 degc for 24 hours heat treatment for am - in718 that eliminates laves and { \ delta } phases, preserves am specific dislocation cells that are shown to be stabilized by mc carbide particles, and precipitates dense { \ gamma ^ { \ prime } and { \ gamma ^ { \ prime \ prime } } nanoparticle populations. this ' optimized for am - in718 heat treatment ' results in superior properties relative to wrought / additively manufactured, then industry standard heat treated in718 : relative increases of 7 / 10 percent in yield strength, 2 / 7 percent in ultimate strength, and 23 / 57 percent in elongation to failure are realized, respectively, regardless of as - built vs. machined surface finishes.
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arxiv:1909.12290
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optimal power flow ( opf ) is a critical optimization problem that allocates power to the generators in order to satisfy the demand at a minimum cost. solving this problem exactly is computationally infeasible in the general case. in this work, we propose to leverage graph signal processing and machine learning. more specifically, we use a graph neural network to learn a nonlinear parametrization between the power demanded and the corresponding allocation. we learn the solution in an unsupervised manner, minimizing the cost directly. in order to take into account the electrical constraints of the grid, we propose a novel barrier method that is differentiable and works on initially infeasible points. we show through simulations that the use of gnns in this unsupervised learning context leads to solutions comparable to standard solvers while being computationally efficient and avoiding constraint violations most of the time.
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arxiv:2210.09277
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properties of octupole vibrations in rapidly rotating nuclei are discussed. microscopic rpa calculations based on the cranked shell model are performed to investigate the interplay between rotation and vibrations. the ability of this model to describe the properties of collective vibrations built on the ground bands in rare - earth and actinide nuclei is demonstrated at high angular momentum. the octupole vibrational states in even - even superdeformed hg nuclei are also predicted and compared with available experimental data. a new interpretation of the observed excited superdeformed bands invoking these octupole bands is proposed.
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arxiv:nucl-th/9509043
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a kochen - specker ( ks ) set is a specific set of projectors and measurement contexts that prove the bell - kochen - specker contextuality theorem. the simplest known ks sets in hilbert space dimensions $ d = 3, 4, 5, 6, 8 $ are reproduced, and several methods by which a new ks set can be constructed using one or more known ks sets in lower dimensions are reviewed and improved. these ks sets and improved methods enable the construction of explicitly critical new ks sets in all dimensions, where critical refers to the irreducibility of the set of contexts. the simplest known critical ks sets are derived in all even dimensions $ d \ geq10 $ with at most 9 contexts and 30 projectors, and in all odd dimensions $ d \ geq 7 $ with at most 13 contexts and 39 projectors. these results show that neither the number of contexts nor the number of projectors in a minimal ks set scales with dimension $ d $.
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arxiv:1702.05215
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hierarchical structures exhibit critical features across multiple scales. however, designing multiscale structures demands significant computational resources, and ensuring connectivity between microstructures remains a key challenge. to address these issues, \ textit { \ textbf { large - range, boundary - identical microstructure datasets } } are successfully constructed, where the microstructures share the same boundaries and exhibit a wide range of elastic moduli. this approach enables highly efficient multiscale topology optimization. central to our technique adopts a deep generative model, guided diffusion, to generate microstructures under the two conditions, including the specified boundary and homogenized elastic tensor. we generate the desired datasets using active learning approaches, where microstructures with diverse elastic moduli are iteratively added to the dataset, which is then retrained. % we achieve the desired datasets by active learning approaches which are alternately adding microstructures with diverse elastic modulus constructed by the deep generative model into the dataset and retraining the deep generative model. after that, sixteen boundary - identical microstructure datasets with wide ranges of elastic modulus % high property coverage are constructed. we demonstrate the effectiveness and practicability of the obtained datasets over various multiscale design examples. specifically, in the design of a mechanical cloak, we utilize macrostructures with $ 30 \ times 30 $ elements and microstructures filled with $ 256 \ times 256 $ elements. the entire reverse design process is completed within one minute, significantly enhancing the efficiency of the multiscale topology optimization.
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arxiv:2406.16066
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we study the dissipative quantum harmonic oscillator with general non - thermal preparations of the harmonic oscillator bath. the focus is on equilibration of the oscillator in the long - time limit and the additional requirements for thermalization. our study is based on the exact solution of the microscopic model obtained by means of operator equations of motion, which provides us with the time evolution of the central oscillator density matrix in terms of the propagating function. we find a hierarchy of conditions for thermalization, together with the relation of the asymptotic temperature to the energy distribution in the initial bath state. we discuss the presence and absence of equilibration for the example of an inhomogeneous chain of harmonic oscillators, and illustrate the general findings about thermalization for the non - thermal environment that results from a quench.
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arxiv:1205.2068
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in this work, the falcon code is adopted for illustrating the features of shear alfv \ ' en and continuous spectra in toroidal fusion plasmas. the falcon codes employs the local floquet analysis discussed in [ phys. of plasmas \ textbf { 26 } ( 8 ), 082502 ( 2019 ) ] for computing global structures of continuous spectra in general toroidal geometry. as particular applications, reference equilibria for the divertor tokamak test and asdex upgrade plasmas are considered. in particular, we illustrate the importance of mode polarization for recognizing the physical relevance of the various branches of the continuous spectra in the ideal mhd limit. we also analyze the effect of plasma compression and the validity of the slow sound approximation.
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arxiv:2004.13179
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achieving high - precision detection of time - dependent signals in noisy environment is a ubiquitous issue in physics and a critical task in metrology. lock - in amplifiers are detectors that can extract alternating signals with a known carrier frequency from an extremely noisy environment. here, we present a protocol for achieving an entanglement - enhanced lock - in amplifier via empoying many - body quantum interferometry and periodic multiple pulses. generally, quantum interferometry includes three stages : initialization, interrogation, and readout. the many - body quantum lock - in amplifier can be achieved via adding suitable periodic multiple - $ \ pi $ - pulse sequence during the interrogation. our analytical results show that, by selecting suitable input states and readout operations, the frequency and amplitude of an unknown alternating field can be simultaneously extracted via population measurements. in particular, if we input spin cat states and apply interaction - based readout operations, the measurement precisions for frequency and amplitude can both approach the heisenberg limit. moreover, our many - body quantum amplifier is robust against extreme stochastic noises. our study may point out a new direction for measuring time - dependent signals with many - body quantum systems, and provides a feasible way for achieving heisenberg - limited detection of alternating signals.
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arxiv:2010.06849
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igr j17591 - - 2342, a transient accretion - powered millisecond x - ray pulsar, was discovered during its 2018 outburst. here, we present a timing and spectral analysis of the source using { \ it astrosat } data of the same outburst. from the timing analysis, we obtain updated values of binary orbital parameters, which reveal an average pulsar spin frequency of 527. 4256984 ( 8 ) hz. the pulse profiles can be fit well with four harmonically related sinusoidal components with fractional amplitudes of fundamental and second, third, and fourth harmonics as $ \ sim13 $ \ %, $ \ sim $ 6 \ %, $ \ sim $ 0. 9 \ %, $ \ sim $ 0. 2 \ %, respectively. the energy - dependent study of pulse profiles in the range of $ 3 - 20 $ kev shows that the fractional amplitude of both the fundamental and first overtone is consistent with being constant across the considered energy band. besides, a decaying trend has been observed for both the fundamental and first overtone in the phase - delay versus energy relation resulting in soft x - ray ( 2. 8 - 3. 3 kev ) phase lags of $ \ sim $ 0. 05 and $ \ sim $ 0. 13 with respect to $ \ leq 15 $ kev photons, for the fundamental and first overtone, respectively. the combined spectra from the large area x - ray proportional counters and the soft x - ray telescope aboard { \ it astrosat } in the $ 1 - 18 $ kev range can be fit well with an absorbed model consisting of a comptonization, a blackbody and a gaussian emission line component yielding as best - fit parameters a blackbody seed photon temperature $ kt _ { \ rm bb } $ $ \ sim 0. 95 \ pm 0. 03 $ kev, and an electron temperature $ kt _ { \ rm e } $ $ \ sim 1. 54 \ pm0. 03 $ kev. the spectral aspects suggest the scattering of photons from the accretion disc or the neutron star ' s surface.
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arxiv:2412.11143
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for a oriented genus g surface with one boundary component, s, the torelli group is the group of orientation preserving homeomorphisms of s that induce the identity on homology. the magnus representation of the torelli group represents the action on f / f " where f = pi _ 1 ( s ) and f " is the second term of the derived series. we show that the kernel of the magnus representation, mag ( s ), is highly non - trivial and has a rich structure as a group. specifically, we define an infinite filtration of mag ( s ) by subgroups, called the higher order magnus subgroups, m _ k ( s ). we develop methods for generating nontrivial mapping classes in m _ k ( s ) for all k and g > 1. we show that for each k the quotient m _ k ( s ) / m _ { k + 1 } ( s ) contains a subgroup isomorphic to a lower central series quotient of free groups e ( g - 1 ) _ k / e ( g - 1 ) _ { k + 1 }. finally we show that for g > 2 the quotient m _ k ( s ) / m _ { k + 1 } ( s ) surjects onto an infinite rank torsion free abelian group. to do this, we define a johnson - type homomorphism on each higher order magnus subgroup quotient and show it has a highly non - trivial image.
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arxiv:1308.3686
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this paper presents a method for computing a finite - blocklength converse for the rate of fixed - length codes with feedback used on discrete memoryless channels ( dmcs ). the new converse is expressed in terms of a stochastic control problem whose solution can be efficiently computed using dynamic programming and fourier methods. for channels such as the binary symmetric channel ( bsc ) and binary erasure channel ( bec ), the accuracy of the proposed converse is similar to that of existing special - purpose converse bounds, but the new converse technique can be applied to arbitrary dmcs. we provide example applications of the new converse technique to the binary asymmetric channel ( bac ) and the quantized amplitude - constrained awgn channel.
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arxiv:2202.04267
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simulating from the multivariate truncated normal distribution ( mtn ) is required in various statistical applications yet remains challenging in high dimensions. currently available algorithms and their implementations often fail when the number of parameters exceeds a few hundred. to provide a general computational tool to efficiently sample from high - dimensional mtns, we introduce the hdtg package that implements two state - of - the - art simulation algorithms : harmonic hamiltonian monte carlo ( harmonic - hmc ) and zigzag hamiltonian monte carlo ( zigzag - hmc ). both algorithms exploit analytical solutions of the hamiltonian dynamics under a quadratic potential energy with hard boundary constraints, leading to rejection - free methods. we compare their efficiencies against another state - of - the - art algorithm for mtn simulation, the minimax tilting accept - reject sampler ( met ). the run - time of these three approaches heavily depends on the underlying multivariate normal correlation structure. zigzag - hmc and harmonic - hmc both achieve 100 effective samples within 3, 600 seconds across all tests with dimension ranging from 100 to 1, 600, while met has difficulty in several high - dimensional examples. we provide guidance on how to choose an appropriate method for a given situation and illustrate the usage of hdtg.
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arxiv:2210.01097
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for any link and for any modulus $ m $ we introduce an equivalence relation on the set of non - trivial m - colorings of the link ( an m - coloring has values in z / mz ). given a diagram of the link, the equivalence class of a non - trivial m - coloring is formed by each assignment of colors to the arcs of the diagram that is obtained from the former coloring by a permutation of the colors in the arcs which preserves the coloring condition at each crossing. this requirement implies topological invariance of the equivalence classes. we show that for a prime modulus the number of equivalence classes depends on the modulus and on the rank of the coloring matrix ( with respect to this modulus ).
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arxiv:1208.0993
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the hyphi collaboration at gsi argued recently for a ( lambda - n - n ) bound state from the observation of its two - body ( t + pi - ) weak - decay mode. we derive constraints from several hypernuclear systems, in particular from the a = 4 hypernuclei with full consideration of ( lambda n < - - > sigma n ) coupling, to rule out a bound ( lambda - n - n ).
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arxiv:1404.5855
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inertia - gravity waves ( igws ) play an essential role in the terrestrial atmospheric dynamics as they can lead to energy and momentum flux when propagating upwards. an open question is to which extent igws contribute to the total energy and to flattening of the energy spectrum observed at the mesoscale. in this work, we present an experimental investigation of the energy distribution between the large - scale balanced flow and the small - scale imbalanced flow. weakly nonlinear igws emitted from baroclinic jets are observed in the differentially heated rotating annulus experiment. similar to the atmospheric spectra, the experimental kinetic energy spectra reveal the typical subdivision into two distinct regimes with slopes $ k ^ { - 3 } $ for the large scales and $ k ^ { - 5 / 3 } $ for the small scales. by separating the spectra into the vortex and the wave component, it emerges that at the large - scale end of the mesoscale the gravity waves observed in the experiment cause a flattening of the spectra and provide most of the energy. at smaller scales, our data analysis suggests a transition towards a turbulent regime with a forward energy cascade up to where dissipation by diffusive processes occurs.
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arxiv:2004.04052
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deep inelastic scattering of leptons from hadrons at small values of the bjorken parameter $ x $ is studied from superstring theory. in particular, we focus on single - flavored scalar and vector mesons in the large $ n $ limit. this is studied in terms of different holographic dual models with flavor dp - branes in type iia and type iib superstring theories, in the strong coupling limit of the corresponding dual gauge theories. we derive the hadronic tensor and the structure functions for scalar and polarized vector mesons. in particular, for polarized vector mesons we obtain the eight structure functions at small values of the bjorken parameter. the main result is that we obtain new relations of the callan - gross type for several structure functions. these relations have similarities for all different dp - brane models that we consider. this would suggest their universal character, and therefore, it is possible that they hold for strongly coupled qcd in the large $ n $ limit.
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arxiv:1412.6509
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