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we systematically study raman spectroscopy of cleaved na $ _ x $ coo $ _ 2 $ single crystals with 0. 37 $ \ leq $ x $ \ leq $ 0. 80. the raman shift of a $ _ { 1g } $ mode is found to be linearly dependent on na content, while the raman shift of e $ _ { 1g } $ mode has an abnormal shift to high frequency around x = 0. 5. the abnormal shift is ascribed to the occurrence of na rearrangement in o1 structure. temperature dependent raman spectrum for x = 0. 56 sample shows that na rearrangement transition from o1 structure to h1 structure occurs around 240 k. electronic transport and susceptibility for the sample with $ x = 0. 56 $ show a response to the na rearrangement transition from o1 to h1 structure, and that different na ordering pattern causes distinct physical properties. these results give a direct evidence to proved na ordering effect on physical properties of co - o plane.
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arxiv:0809.0096
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in this paper we construct the fermi coordinates along any arbitrary line in simple analytical way without use the orthogonal frames and their parallel transport. in this manner we extend the eddington approach to the construction of the fermi metric in terms of the riemann tensor. in the second part of the present article we show how the proposed approach works practically by applying it for deriving the fermi coordinates for the static observer in the schwarzschild spacetime.
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arxiv:2007.07074
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in this paper, we study a family of rank two false theta series associated to the root lattice of type $ a _ 2 $. we show that these functions appear as fourier coefficients of a meromorphic jacobi form of negative definite matrix index. hypergeometric $ q $ - series identities are also obtained.
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arxiv:1902.10554
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while friction stems from the fundamental interactions between atoms at a contact interface, its best descriptions at the macroscopic scale remain phenomenological. the so called " rate - and - state " models, which specify the friction response in terms of the relative sliding velocity and the " age " of the contact interface, fail to uncover the nano - scale mechanisms governing the macro - scale response, while models of friction at the atomic scale often overlook how roughness can alter the friction behavior. here we bridge this gap between nano and macro descriptions of friction by correlating the physical origin of macroscopic friction to the existence, due to nanometric roughness, of contact junctions between adsorbed monolayers. their dynamics, as we show, emerges from molecular motion. through coupled experimental and atomic simulations, we highlight that transient friction overshoots its steady - state value after the system is allowed to rest, with the friction force decaying to a steady - state value over a distance of a few nanometers, much smaller than the junction size, even with a root - mean - square roughness of 0. 6 nm. we demonstrate how this transient decay is intrinsically related to the evolution of the number of cross - surface attractive physical links between adsorbed molecules on rough surfaces. we also show that roughness is a sufficient condition for the appearance of frictional aging. in systems that show structural aging, this paints contact junctions as a key component in the observation of the transient friction overshoot, and shows how infrajunction molecular motion can control the macroscopic response.
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arxiv:2111.13588
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we first identify ( up to linear isomorphism ) the lipschitz free spaces of quasiarcs. by decomposing quasiconformal trees into quasiarcs as done in an article of david, eriksson - bique, and vellis, we then identify the lipschitz free spaces of quasiconformal trees and prove that quasiconformal trees have lipschitz dimension 1. generalizing the aforementioned decomposition, we define a geometric tree - like decomposition of a metric space. our results pertaining to quasiconformal trees are in fact special cases of results about metric spaces admitting a geometric tree - like decomposition. furthermore, the methods employed in our study of lipschitz free spaces yield a decomposition of any ( weak ) quasiarc into rectifiable and purely unrectifiable subsets, which may be of independent interest.
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arxiv:2204.05464
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for a positive integer $ n $, let $ b _ { \ ell _ 1, \ dots, \ ell _ r } ( n ) $ denote the number of $ ( \ ell _ 1, \ ell _ 2, \ cdots, \ ell _ r ) $ - regular multipartitions of $ n $. if $ \ ell _ 1 = \ ell _ 2 = \ cdots = \ ell _ r = \ ell $, then we denote $ b _ { \ ell _ 1, \ dots, \ ell _ r } ( n ) $ as $ b _ \ ell ^ { ( r ) } ( n ) $. in this paper, we prove several infinite families of congruences satisfied by $ b _ \ ell ^ { ( r ) } ( n ) $ for different values of $ \ ell $ and $ r $.
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arxiv:2311.03248
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the maximization for the independence systems defined on graphs is a generalization of combinatorial optimization problems such as the maximum $ b $ - matching, the unweighted max - sat, the matchoid, and the maximum timed matching problems. in this paper, we consider the problem under the local oracle model to investigate the global approximability of the problem by using the local approximability. we first analyze two simple algorithms fixedorder and greedy for the maximization under the model, which shows that they have no constant approximation ratio. here algorithms fixedorder and greedy apply local oracles with fixed and greedy orders of vertices, respectively. we then propose two approximation algorithms for the $ k $ - degenerate graphs, whose approximation ratios are $ \ alpha + 2k - 2 $ and $ \ alpha k $, where $ \ alpha $ is the approximation ratio of local oracles. the second one can be generalized to the hypergraph setting. we also propose an $ ( \ alpha + k ) $ - approximation algorithm for bipartite graphs, in which the local independence systems in the one - side of vertices are $ k $ - systems with independence oracles.
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arxiv:2208.10003
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this work is motivated by the difficulty in assembling the galerkin matrix when solving partial differential equations ( pdes ) with isogeometric analysis ( iga ) using b - splines of moderate - to - high polynomial degree. to mitigate this problem, we propose a novel methodology named cossiga ( compressive isogeometric analysis ), which combines the iga principle with corsing, a recently introduced sparse recovery approach for pdes based on compressive sensing. cossiga assembles only a small portion of a suitable iga petrov - galerkin discretization and is effective whenever the pde solution is sufficiently sparse or compressible, i. e., when most of its coefficients are zero or negligible. the sparsity of the solution is promoted by employing a multilevel dictionary of b - splines as opposed to a basis. thanks to sparsity and the fact that only a fraction of the full discretization matrix is assembled, the proposed technique has the potential to lead to significant computational savings. we show the effectiveness of cossiga for the solution of the 2d and 3d poisson equation over nontrivial geometries by means of an extensive numerical investigation.
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arxiv:2003.06475
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one of the fundamental quests of ai is to produce agents that coordinate well with humans. this problem is challenging, especially in domains that lack high quality human behavioral data, because multi - agent reinforcement learning ( rl ) often converges to different equilibria from the ones that humans prefer. we propose a novel framework, instructrl, that enables humans to specify what kind of strategies they expect from their ai partners through natural language instructions. we use pretrained large language models to generate a prior policy conditioned on the human instruction and use the prior to regularize the rl objective. this leads to the rl agent converging to equilibria that are aligned with human preferences. we show that instructrl converges to human - like policies that satisfy the given instructions in a proof - of - concept environment as well as the challenging hanabi benchmark. finally, we show that knowing the language instruction significantly boosts human - ai coordination performance in human evaluations in hanabi.
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arxiv:2304.07297
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generating plausible and fluent sentence with desired properties has long been a challenge. most of the recent works use recurrent neural networks ( rnns ) and their variants to predict following words given previous sequence and target label. in this paper, we propose a novel framework to generate constrained sentences via gibbs sampling. the candidate sentences are revised and updated iteratively, with sampled new words replacing old ones. our experiments show the effectiveness of the proposed method to generate plausible and diverse sentences.
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arxiv:1802.08970
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we use coupled - cluster quantum chemical methods to calculate the energetics of molecular clusters cut out of periodic molecular hydrogen structures that model observed phases of solid hydrogen. the hydrogen structures are obtained from kohn - sham density functional theory ( dft ) calculations at pressures of 150, 250 and 350 gpa, which are within the pressure range in which phases ii, iii and iv are found to be stable. the calculated deviations in the dft energies from the coupled - cluster data are reported for different functionals, and optimized functionals are generated which provide reduced errors. we give recommendations for semi - local and hybrid density functionals that are expected to accurately describe hydrogen at high pressures.
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arxiv:1611.00371
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in this work we investigate the accuracy of standard and state - of - the - art language identification methods in identifying albanian in written text documents. a dataset consisting of news articles written in albanian has been constructed for this purpose. we noticed a considerable decrease of accuracy when using test documents that miss the albanian alphabet letters " \ " e " and " \ c { c } " and created a custom training corpus that solved this problem by achieving an accuracy of more than 99 %. based on our experiments, the most performing language identification methods for albanian use a na \ " ive bayes classifier and n - gram based classification features.
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arxiv:1901.04216
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we study standing - wave solutions of born - infeld electrodynamics, with nonzero electromagnetic field in a region between two parallel conducting plates. we consider the simplest case which occurs when the vector potential describing the electromagnetic field has only one nonzero component depending on time and on the coordinate perpendicular to the plates. the problem then reduces to solving the scalar born - infeld equation, a nonlinear partial differential equation in 1 + 1 dimensions. we apply two alternative methods to obtain standing - wave solutions to the born - infeld equation : an iterative method, and a ` ` minimal surface ' ' method. we also study standing wave solutions in a uniform constant magnetic field background.
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arxiv:2006.09053
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this paper investigates various methods of representing 3d rotations and their impact on the learning process of deep neural networks. we evaluated the performance of resnet18 networks for 3d rotation estimation using several rotation representations and loss functions on both synthetic and real data. the real datasets contained 3d scans of industrial bins, while the synthetic datasets included views of a simple asymmetric object rendered under different rotations. on synthetic data, we also assessed the effects of different rotation distributions within the training and test sets, as well as the impact of the object ' s texture. in line with previous research, we found that networks using the continuous 5d and 6d representations performed better than the discontinuous ones.
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arxiv:2410.10350
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in recent years, there has been a development in approaching rationality problems through the motivic methods ( cf. [ kontsevich - - tschinkel ' 19 ], [ nicaise - - shinder ' 19 ], [ nicaise - - ottem ' 21 ] ). this method requires the explicit construction of degeneration families of curves with favorable properties. while the specific construction is generally difficult, [ nicaise - - ottem ' 22 ] combines combinatorial methods to construct degeneration families of hypersurfaces in toric varieties and shows the non - stable rationality of a very general hypersurface in projective spaces. in this paper, we extend the result of [ nicaise - - ottem ' 22 ] not only for hypersurfaces in algebraic tori but also to those in sch \ " { o } n affine varieties. in application, we show the irrationality of certain hypersurfaces in the complex grassmannian variety gr ( 2, n ) using the motivic method, which coincides with the result obtained by the same author in the previous research.
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arxiv:2502.08153
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we present a galerkin - collocation domain decomposition algorithm applied to the evolution of cylindrical unpolarized gravitational waves. we show the effectiveness of the algorithm in reproducing initial data with high localized gradients and in providing highly accurate dynamics. we characterize the gravitational radiation with the standard newman - penrose weyl scalar $ \ psi _ 4 $. we generate wave templates for both polarization modes, $ \ times $ and $ + $, outgoing and ingoing, to show how they exchange energy nonlinearly. in particular, considering an initially ingoing $ \ times $ wave, we were able to trace a possible imprint of the gravitational analog of the faraday effect in the generated templates.
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arxiv:1802.00095
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the concept of a small, single - layer water cherenkov detector, with three photomultiplier tubes ( pmts ), placed at its bottom in a $ 120 ^ { \ circ } $ star configuration ( \ emph { mercedes } water cherenkov detector ) is presented. the pmts are placed near the lateral walls of the stations with an adjustable inclination and may be installed inside or outside the water volume. to illustrate the technical viability of this concept and obtain a first - order estimation of its cost, an engineering design was elaborated. the sensitivity of these stations to low energy extensive air shower ( eas ) electrons, photons and muons is discussed, both in compact and sparse array configurations. it is shown that the analysis of the intensity and time patterns of the pmt signals, using machine learning techniques, enables the tagging of muons, achieving an excellent gamma / hadron discrimination for tev showers. this concept minimises the station production and maintenance costs, allowing for a highly flexible and fast installation. mercedes water cherenkov detectors ( wcds ) are thus well - suited for use in high - altitude large gamma - ray observatories covering an extended energy range from the low energies, closing the gap between satellite and ground - based measurements, to very high energy regions, beyond the pev scale.
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arxiv:2203.08782
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following our previous investigation of the usa standard and poor index anti - bubble that started in august 2000, we analyze thirty eight world stock market indices and identify 21 anti - bubble. an ` ` anti - bubble ' ' is defined as a self - fulfilling decreasing price created by positive price - to - price feedbacks feeding overall pessimism and negative market sentiment further strengthened by inter - personal interactions. we mathematically characterize anti - bubbles by a power law decrease of the price ( or of the logarithm of the price ) as a function of time and by decelerating / expanding log - periodic oscillations. the majority of european and western stock market indices as well as other stock indices exhibit practically the same log - periodic power law anti - bubble structure as found for the usa s & p500 index. these anti - bubbles are found to start approximately at the same time, august 2000, in all these markets. this shows a remarkable degree of synchronization worldwide. the descent of the worldwide stock markets since 2000 is thus an international event, suggesting the strengthening of globalization.
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arxiv:cond-mat/0212010
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part i. some facts from p - adic analysis. part ii. tables of integrals.
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arxiv:math-ph/9911027
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it has been widely believed that, except in very extreme situations, the influence of gravity on quantum fields should amount to just small, sub - dominant contributions. this view seemed to be endorsed by the seminal results obtained over the last decades in the context of renormalization of quantum fields in curved spacetimes. here, however, we argue that this belief is false by showing that there exist well - behaved spacetime evolutions where the vacuum energy density of free quantum fields is forced, by the very same background spacetime, to become dominant over any classical energy - density component. this semiclassical gravity effect finds its roots in the infrared behavior of fields on curved spacetimes. by estimating the time scale for the vacuum energy density to become dominant, and therefore for backreaction on the background spacetime to become important, we argue that this vacuum dominance may bear unexpected astrophysical and cosmological implications.
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arxiv:1003.3421
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visual object tracking aims to estimate the location of an arbitrary target in a video sequence given its initial bounding box. by utilizing offline feature learning, the siamese paradigm has recently been the leading framework for high performance tracking. however, current existing siamese trackers either heavily rely on complicated anchor - based detection networks or lack the ability to resist to distractors. in this paper, we propose the siamese keypoint prediction network ( siamkpn ) to address these challenges. upon a siamese backbone for feature embedding, siamkpn benefits from a cascade heatmap strategy for coarse - to - fine prediction modeling. in particular, the strategy is implemented by sequentially shrinking the coverage of the label heatmap along the cascade to apply loose - to - strict intermediate supervisions. during inference, we find the predicted heatmaps of successive stages to be gradually concentrated to the target and reduced to the distractors. siamkpn performs well against state - of - the - art trackers for visual object tracking on four benchmark datasets including otb - 100, vot2018, lasot and got - 10k, while running at real - time speed.
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arxiv:2006.04078
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automotive mmwave radar has been widely used in the automotive industry due to its small size, low cost, and complementary advantages to optical sensors ( e. g., cameras, lidar, etc. ) in adverse weathers, e. g., fog, raining, and snowing. on the other side, its large wavelength also poses fundamental challenges to perceive the environment. recent advances have made breakthroughs on its inherent drawbacks, i. e., the multipath reflection and the sparsity of mmwave radar ' s point clouds. however, the frequency - modulated continuous wave modulation of radar signals makes it more sensitive to vehicles ' mobility than optical sensors. this work focuses on the problem of frequency shift, i. e., the doppler effect distorts the radar ranging measurements and its knock - on effect on metric localization. we propose a new radar - based metric localization framework, termed dc - loc, which can obtain more accurate location estimation by restoring the doppler distortion. specifically, we first design a new algorithm that explicitly compensates the doppler distortion of radar scans and then model the measurement uncertainty of the doppler - compensated point cloud to further optimize the metric localization. extensive experiments using the public nuscenes dataset and carla simulator demonstrate that our method outperforms the state - of - the - art approach by 25. 2 % and 5. 6 % improvements in terms of translation and rotation errors, respectively.
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arxiv:2112.14887
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spin - torque nano - oscillators can emulate neurons at the nanoscale. recent works show that the non - linearity of their oscillation amplitude can be leveraged to achieve waveform classification for an input signal encoded in the amplitude of the input voltage. here we show that the frequency and the phase of the oscillator can also be used to recognize waveforms. for this purpose, we phase - lock the oscillator to the input waveform, which carries information in its modulated frequency. in this way we considerably decrease amplitude, phase and frequency noise. we show that this method allows classifying sine and square waveforms with an accuracy above 99 % when decoding the output from the oscillator amplitude, phase or frequency. we find that recognition rates are directly related to the noise and non - linearity of each variable. these results prove that spin - torque nano - oscillators offer an interesting platform to implement different computing schemes leveraging their rich dynamical features.
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arxiv:1811.00309
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previous cross - lingual transfer methods are restricted to orthographic representation learning via textual scripts. this limitation hampers cross - lingual transfer and is biased towards languages sharing similar well - known scripts. to alleviate the gap between languages from different writing scripts, we propose phonexl, a framework incorporating phonemic transcriptions as an additional linguistic modality beyond the traditional orthographic transcriptions for cross - lingual transfer. particularly, we propose unsupervised alignment objectives to capture ( 1 ) local one - to - one alignment between the two different modalities, ( 2 ) alignment via multi - modality contexts to leverage information from additional modalities, and ( 3 ) alignment via multilingual contexts where additional bilingual dictionaries are incorporated. we also release the first phonemic - orthographic alignment dataset on two token - level tasks ( named entity recognition and part - of - speech tagging ) among the understudied but interconnected chinese - japanese - korean - vietnamese ( cjkv ) languages. our pilot study reveals phonemic transcription provides essential information beyond the orthography to enhance cross - lingual transfer and bridge the gap among cjkv languages, leading to consistent improvements on cross - lingual token - level tasks over orthographic - based multilingual plms.
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arxiv:2307.04361
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the interaction of a bulk electron with conducting surfaces is studied by means of bohm - pines transformation in the second quantization formalism. the effective interaction potentials are obtained for the case of one plane and two plane configurations in the form of electron - image electron scattering.
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arxiv:cond-mat/0205425
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evolution of genus density is calculated from gaussian initial conditions using zel ' dovich approximation. a new approach is introduced which formulates the desired quantity in a rotationally invariant manner. it is shown that normalized genus density does not depend on the initial spectral shape but is a function of the fluctuation amplitude only.
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arxiv:astro-ph/9610185
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the majority of stars are now thought to support exoplanets. many of those exoplanets discovered thus far are categorized as rocky objects with an atmosphere. most of these objects are however hot due to their short orbital period. models suggest that water is the dominant species in their atmospheres. the hot temperatures are expected to turn these atmospheres into a ( high pressure ) steam bath containing remains of melted rock. the spectroscopy of these hot rocky objects will be very different from that of cooler objects or hot gas giants. molecules suggested to be important for the spectroscopy of these objects are reviewed together with the current status of the corresponding spectroscopic data. perspectives of building a comprehensive database of linelist / cross sections applicable for atmospheric models of rocky super - earths as part of the exomol project are discussed. the quantum - mechanical approaches used in linelist productions and their challenges are summarized.
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arxiv:1705.07198
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recently, there has been a growing interest in integrated thz photonics for various applications in communications, spectroscopy and sensing. we present a new integrated photonic platform based on active and passive elements integrated in a double - metal, high confinement waveguide layout planarized with a low - loss polymer. an extended top metallization results in low waveguide losses and improved dispersion, thermal and rf properties, as it enables to decouple the design of thz and microwave cavities. free - running on - chip quantum cascade laser combs spanning 800 ghz, harmonic states over 1. 1 thz and rf - injected broadband incoherent states spanning over nearly 1. 6 thz are observed. with a strong external rf drive, actively mode - locked pulses as short as 4. 4 ps can be produced, as measured by swifts. we demonstrate as well passive waveguides with low insertion loss, enabling the tuning of the laser cavity boundary conditions and the co - integration of active and passive components on the same thz photonic chip.
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arxiv:2207.06737
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we study the phenomenon of spin - current rectification in a one - dimensional xxz spin chain in the presence of a thermal drive. in our model a pure spin current is generated by a temperature difference between two harmonic heat baths which in turn creates a spin voltage via the spin - seebeck effect. along with a local spin - current operator definition and the nonequilibrium modified redfield solution we study the spin - rectification ratio as a function of system size and external magnetic field. intriguing effects are observed at low temperatures such as oscillations with system size and high range of tunability with external magnetic field making magnetic insulators, which are well described by the xxz model, ideal candidates to build spin devices based on rectification.
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arxiv:1307.5622
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our study focuses on wikipedia talk pages, from a global perspective analyzing contributors ' behaviors in online interactions. using a corpus comprising all wikipedia talk pages in french, totaling more than 300, 000 discussion threads, we examine how discussions with more than two participants ( multiparty conversation ) unfold and we specifically investigate the role of a third participant ' s intervention when two wikipedians have already initiated an exchange. in this regard, we concentrate on the sequential structure of these interactions in terms of articulation among different participants and aim to specify this third message by exploring its lexical particularities, while also proposing an initial typology of the third participant ' s message role and how it aligns with preceding messages.
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arxiv:2406.19731
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the unlicensed spectrum is recently considered one of the defining solutions to meet the steadily growing traffic demand. this, in turn, has led to the enhancement for lte in release - 13 to enable licensed - assisted access ( laa ) operations. the design of the medium access control ( mac ) protocol for the laa system to harmonically coexist with the incumbent wlan system operating in an unlicensed band is critical and challenging. in this paper, we consider an integrated access and backhaul ( iab ) system coexisting with a wi - fi network operating at millimeter - wave ( mmwave ) unlicensed spectrum, for which a listen - before - talk - based ( lbt ) based medium access mechanism is carefully designed. additionally, we have considered an in - band system that supports both access and backhaul in a single node where the small - cell or the iab nodes compete with the wigig for medium access. we present comprehensive experimental results and give design insights based on the simulation results.
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arxiv:2104.09571
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we construct a lift of schur ' s q - functions to the peak algebra of the symmetric group, called the noncommutative schur q - functions, and extract from them a new natural basis with several nice properties such as the positive right - pieri rule, combinatorial expansion, etc. dually, we get a basis of the stembridge algebra of peak functions refining schur ' s p - functions in a simple way.
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arxiv:1408.6045
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spectral weight is investigated for metallic diagonal stripe state in two dimensional hubbard model, and fermi arc observed by angle - resolved photoemission spectroscopy on lsco is discussed. the fermi arc coming from the mid - gap state of diagonal stripe appears near $ ( \ frac { \ pi } { 2 }, \ frac { \ pi } { 2 } ) $ and equivalent position in the reciprocal space, and the gap opens below the mid - gap state. we show how these spectral weight structure depends on the phasing of stripes, i. e., site - centered or bond - centered stripes.
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arxiv:cond-mat/0307685
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we have determined the solar modulation potential, phi, vs. time that is observed at voyager 1 and 2 from measurements of the h and he nuclei intensities at a common energy of 250 mevnuc. the h nuclei have a rigidity 0. 7 gv, the he nuclei 1. 4 gv. these measurements cover a 40 year time period, which includes almost 4 cycles of solar 11 year sunspot variations, throughout the inner heliosphere out to the hts at distances of 95 au and 85 au, respectively at v1 and v2, and then beyond in the heliosheath. inside the hts the modulation potential vs. time curves at v1 and v2 show a very similar temporal structure to those observed at the earth. during a later period of maximum solar modulation from 2000. 0 to 2005. 0 when v1 and v2 are in the outer heliosphere between 60 - 94 au, the main temporal features of the modulation potential curves at all 3 locations match up with appropriate time delays at v1 and v2 if it is assumed that spatially coherent structures are moving outward past v1 and v2, with outward speeds of up to 700 kms negative 1. after 2004. 0 v1 and v2 are at latitudes of positive 35 and negative 30 respectively, placing lower limits on the latitude extent of these structures. beyond the hts in the heliosheath the modulation potential slowly decreases at both spacecraft with only a weak evidence of the unusual modulation minimum observed at the earth in 2009, for example. a sudden decrease of the modulation potential 50 mv for both h and he nuclei occurs at v1 just before the heliopause crossing at about 122 au. this decrease has not yet been observed at v2, which is now at 113 au and still observing a modulation potential 60 mv.
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arxiv:1706.02772
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the cellular internet - of - things has resulted in the deployment of millions of machine - type communication ( mtc ) devices. these massive number of devices must communicate with a single gnodeb ( gnb ) via the random access channel ( rach ) mechanism. however, existing rach mechanisms are inefficient when dealing with such large number of devices. to address this issue, we propose the rate - splitting random access ( rsra ) mechanism, which uses rate splitting and decoding in rate - splitting multiple access ( rsma ) to improve rach success rates. the proposed mechanism divides the message into common and private messages and enhances the decoding performance. we demonstrate, using extensive simulations, that the proposed rsra mechanism significantly improves the success rate of mtc in cellular iot networks. we also evaluate the performance of the proposed mechanism with increasing number of devices and received power difference.
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arxiv:2106.14621
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modern models of event causality detection ( ecd ) are mainly based on supervised learning from small hand - labeled corpora. however, hand - labeled training data is expensive to produce, low coverage of causal expressions and limited in size, which makes supervised methods hard to detect causal relations between events. to solve this data lacking problem, we investigate a data augmentation framework for ecd, dubbed as knowledge enhanced distant data augmentation ( knowdis ). experimental results on two benchmark datasets eventstoryline corpus and causal - timebank show that 1 ) knowdis can augment available training data assisted with the lexical and causal commonsense knowledge for ecd via distant supervision, and 2 ) our method outperforms previous methods by a large margin assisted with automatically labeled training data.
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arxiv:2010.10833
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astronomical observations have shown that the expansion of the universe is at present accelerating, consistently with a constant negative pressure or tension. this is a major puzzle because we do not understand why this tension is so small compared to the planck density ; why, being so small, it is not exactly zero ; and why it has precisely the required value to make the expansion start accelerating just at the epoch when we are observing the universe. the recently proposed conjecture by afshordi that black holes create a gravitational aether owing to quantum gravity effects, which may be identified with this invisible tension, can solve this coincidence problem. the fact that the expansion of the universe is starting to accelerate at the epoch when we observe it is a necessity that is implied by our origin in a planet orbiting a star that formed when the age of the universe was of the same order as the lifetime of the star. this argument is unrelated to any anthropic reasoning.
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arxiv:1003.6065
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we study the dynamics of maps arising from the composition of two non - commuting involution on a k3 surface. these maps are a particular example of reversible maps, i. e., maps with a time reversing symmetry. the combinatorics of the cycle distribution of two non - commuting involutions on a finite phase space was studied by roberts and vivaldi. we show that the dynamical systems of these k3 surfaces satisfy the hypotheses of their results, providing a description of the cycle distribution of the rational points over finite fields. furthermore, we extend the involutions to include the case where there are degenerate fibers and prove a description of the cycle distribution in this more general situation.
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arxiv:1309.6598
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we present a study of the paramagnetic metallic and insulating phases of vanadium sesquioxide by means of the $ n $ th order muffin - tin orbital implementation of density functional theory combined with dynamical mean - field theory. the transition is shown to be driven by a correlation - induced enhancement of the crystal field splitting within the $ t _ { 2g } $ manifold, which results in a suppression of the hybridization between the $ a _ { 1g } $ and $ e _ g ^ { \ pi } $ bands. we discuss the changes in the effective quasi - particle band structure caused by the correlations and the corresponding self - energies. at temperatures of about 400 k we find the $ a _ { 1g } $ orbitals to display coherent quasi - particle behavior, while a large imaginary part of the self - energy and broad features in the spectral function indicate that the $ e _ g ^ { \ pi } $ orbitals are still far above their coherence temperature. the local spectral functions are in excellent agreement with recent bulk sensitive photoemission data. finally, we also make a prediction for angle - resolved photoemission experiments by calculating momentum - resolved spectral functions.
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arxiv:cond-mat/0701263
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the paper presents the phenomenological analysis of the energy dependence for the ratio of elastic to total cross section in proton - proton and antiproton - proton scattering. the analytic functions based on the study of low - and high - energy experimental data for various scattering parameters provide the quantitative description of energy dependence of the ratio with statistically acceptable qualities in wide range of collision energy $ \ sqrt { s } \ geq 3 $ gev in the case of the separate datasets for $ pp $, $ \ bar { p } p $ collisions and at $ \ sqrt { s } \ geq 5 $ gev for the joined experimental data ensemble. based on the fit results the estimations are derived for the ratio of elastic to total cross section in $ pp $ scattering at various $ \ sqrt { s } $ up to energy frontier $ \ sqrt { s } = 10 $ pev which can be useful for present and future hadron colliders as well as for cosmic ray measurements at ultra - high energies. the indication is observed for onset of the asymptotic region at $ \ sqrt { s } \ gtrsim 5 - 10 $ pev for the ratio of cross sections under consideration.
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arxiv:1805.10514
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i study the dynamics of a josephson junction serving as a threshold detector of fluctuations which is subjected to a general non - equilibrium electronic noise source whose characteristics is to be determined by the junction. this experimental setup has been proposed several years ago as a prospective scheme for determining the full counting statistics of the electronic noise source. despite of intensive theoretical as well as experimental research in this direction the promise has not been quite fulfilled yet and i will discuss what are the unsolved issues. first, i review a general theory for the calculation of the exponential part of the non - equilibrium switching rates of the junction and compare its predictions with previous results found in different limiting cases by several authors. i identify several possible weak points in the previous studies and i report a new analytical result for the linear correction to the rate due to the third cumulant of a non - gaussian noise source in the limit of a very weak junction damping. the various analytical predictions are then compared with the results of the developed numerical method. finally, i analyze the status of the so - far publicly available experimental data with respect to the theoretical predictions and discuss briefly the suitability of the present experimental schemes in view of their potential to measure the whole fcs of non - gaussian noise sources as well as their relation to the available theories.
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arxiv:0807.0387
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we investigate the role of the permutationally invariant part of the density matrix ( pidm ) in capturing the properties of the ground state of the system during a quantum phase transition. in the context of quantum state tomography, pidm is known to be obtainable with only a low number of measurement settings, namely $ \ mathcal { o } ( l ^ 2 ) $, where $ l $ is the system size. considering the transverse - field ising chain as an example, we compute the second - order r \ ' enyi entropy of pidm for the ground state by using the density matrix renormalization group algorithm. in the ferromagnetic case, the ground state is permutationally invariant both in the limits of zero and infinite field, leading to vanishing r \ ' enyi entropy of pidm. the latter exhibits a broad peak as a function of the transverse field around the quantum critical point, which gets more pronounced for larger system size. in the antiferromagnetic case, the peak structure disappears and the r \ ' enyi entropy diverges like $ \ mathcal { o } ( l ) $ in the whole field range of the ordered phase. we discuss the cause of these behaviors of the r \ ' enyi entropy of pidm, examining the possible application of this experimentally tractable quantity to the analysis of phase transition phenomena.
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arxiv:2404.08389
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motion of cantilever near sample surfaces exhibits additional friction even before two bodies come into mechanical contact. called non - contact friction ( ncf ), this friction is of great practical importance to the ultrasensitive force detection measurements. observed large ncf of a micron - scale cantilever found anomalously large damping that exceeds theoretical predictions by 8 - 11 orders of magnitude. this finding points to contribution beyond fluctuating electromagnetic fields within van der waals approach. recent experiments reported by saitoh et al. ( phys. rev. lett. 105, 236103 ( 2010 ) ) also found nontrivial distance dependence of ncf. motivated by these observations, we propose a mechanism based on the coupling of cantilever to the relaxation dynamics of surface defects. we assume that the surface defects couple to the cantilever tip via spin - spin coupling and their spin relaxation dynamics gives rise to the backaction terms and modifies both the friction coefficient and the spring constant. we explain the magnitude, as well as the distance dependence of the friction due to these backaction terms. reasonable agreement is found with the experiments.
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arxiv:1201.6378
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observations of the high - $ z $ universe from jwst have revealed a new population of bright, early galaxies. a robust statistical interpretation of this data requires fast forward models that account for uncertainties in galaxy evolution and incorporate observational systematic effects. we present a probabilistic framework for population synthesis of high - $ z $ galaxies and inference of their properties. our framework is based on the semi - analytic galaxy - formation model galacticus. to infer the astrophysical parameters governing high - $ z $ galaxy evolution, we analyze jwst data from the ceers and ngdeep surveys and calculate the likelihood of observing individual objects in apparent magnitude - - redshift space, for $ z \ geq8. 5 $ galaxy candidates. we include observational selection effects due to limited survey volume and depth, as well as photometric redshift uncertainties. we recover the posterior probability distribution for parameters describing star formation and outflow rates. we place an upper limit on the star formation timescale of $ 500 ~ \ mathrm { myr } $ at a disk velocity of $ 50 ~ \ mathrm { km \ s } ^ { - 1 } $, and we infer a characteristic velocity at which the outflow mass - loading factor is $ \ sim 1 $ of $ 150 ^ { + 280 } _ { - 60 } ~ \ mathrm { km \ s } ^ { - 1 } $, both at $ 95 \ % $ confidence. marginalizing over our astrophysical model, we find that galaxies in ceers and ngdeep data occupy halos with virial masses $ 10 ^ { 10 \ pm 0. 5 } ~ m _ { \ mathrm { \ odot } } $ at $ 8. 5 \ leq z \ leq 12 $, at $ 95 \ % $ confidence. the star formation timescale preferred by our fit is relatively short compared to typical values at lower redshifts, consistent with previous findings. the modeling and analysis framework presented here can enable systematic tests of high - $ z $ galaxies ' dust content, initial mass functions, and star formation burstiness in the future.
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arxiv:2410.11680
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this document presents in detail the work done for the sexism detection task at exist2021 workshop. our methodology is built on ensembles of transformer - based models which are trained on different background and corpora and fine - tuned on the provided dataset from the exist2021 workshop. we report accuracy of 0. 767 for the binary classification task ( task1 ), and f1 score 0. 766, and for the multi - class task ( task2 ) accuracy 0. 623 and f1 - score 0. 535.
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arxiv:2110.15905
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we study the lattice agreement ( la ) and atomic snapshot problems in asynchronous message - passing systems where up to $ f $ nodes may crash. our main result is a crash - tolerant atomic snapshot algorithm with \ textit { amortized constant round complexity }. to the best of our knowledge, the best prior result is given by delporte et al. [ tpds, 18 ] with amortized $ o ( n ) $ complexity if there are more scans than updates. our algorithm achieves amortized constant round if there are $ \ omega ( \ sqrt { k } ) $ operations, where $ k $ is the number of actual failures in an execution and is bounded by $ f $. moreover, when there is no failure, our algorithm has $ o ( 1 ) $ round complexity unconditionally. to achieve amortized constant round complexity, we devise a simple \ textit { early - stopping } lattice agreement algorithm and use it to " order " the update and scan operations for our snapshot object. our la algorithm has $ o ( \ sqrt { k } ) $ round complexity. it is the first early - stopping la algorithm in asynchronous systems.
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arxiv:2008.11837
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in 2018, renes [ ieee trans. inf. theory, vol. 64, no. 1, pp. 577 - 592 ( 2018 ) ] ( arxiv : 1701. 05583 ) developed a general theory of channel duality for classical - input quantum - output ( cq ) channels. that result showed that a number of well - known duality results for linear codes on the binary erasure channel could be extended to general classical channels at the expense of using dual problems which are intrinsically quantum mechanical. one special case of this duality is a connection between coding for error correction ( resp. wire - tap secrecy ) on the quantum pure - state channel ( psc ) and coding for wire - tap secrecy ( resp. error correction ) on the classical binary symmetric channel ( bsc ). while this result has important implications for classical coding, the machinery behind the general duality result is rather challenging for researchers without a strong background in quantum information theory. in this work, we leverage prior results for linear codes on pscs to give an alternate derivation of the aforementioned special case by computing closed - form expressions for the performance metrics. the noted prior results include optimality of the square - root measurement ( srm ) for linear codes on the psc and the fourier duality of linear codes. we also show that the srm forms a suboptimal measurement for channel coding on the bsc ( when interpreted as a cq problem ) and secret communications on the psc. our proofs only require linear algebra and basic group theory, though we use the quantum dirac notation for convenience.
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arxiv:2103.09225
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orthogonal matching pursuit ( omp ) plays an important role in data science and its applications such as sparse subspace clustering and image processing. however, the existing omp - based approaches lack of data adaptiveness so that the data cannot be represented well enough and may lose the accuracy. this paper proposes a novel approach to enhance the data - adaptive capability for omp - based sparse subspace clustering. in our method a parameter selection process is developed to adjust the parameters based on the data distribution for information representation. our theoretical analysis indicates that the parameter selection process can efficiently coordinate with any omp - based methods to improve the clustering performance. also a new self - expressive - affinity ( sea ) ratio metric is defined to measure the sparse representation conversion efficiency for spectral clustering to obtain data segmentations. our experiments show that proposed approach can achieve better performances compared with other omp - based sparse subspace clustering algorithms in terms of clustering accuracy, sea ratio and representation quality, also keep the time efficiency and anti - noise ability.
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arxiv:1903.01734
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a finite group $ g $ is called $ \ psi $ - divisible if $ \ psi ( h ) | \ psi ( g ) $ for any subgroup $ h $ of $ g $, where $ \ psi ( h ) $ and $ \ psi ( g ) $ are the sum of element orders of $ h $ and $ g $, respectively. in this paper, we extend a result provided in [ 10 ], by classifying the finite groups whose all subgroups are $ \ psi $ - divisible. since the existence of $ \ psi $ - divisible groups is related to the class of square - free order groups, we also study the sum of element orders and the $ \ psi $ - divisibility property of zm - groups. in the end, we introduce the concept of $ \ psi $ - normal divisible group, i. e. a group for which the $ \ psi $ - divisibility property is satisfied by all its normal subgroups. using simple and quasisimple groups, we are able to construct infinitely many $ \ psi $ - normal divisible groups which are neither simple nor nilpotent.
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arxiv:2003.01678
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a principal designs an algorithm that generates a publicly observable prediction of a binary state. she must decide whether to act directly based on the prediction or to delegate the decision to an agent with private information but potential misalignment. we study the optimal design of the prediction algorithm and the delegation rule in such environments. three key findings emerge : ( 1 ) delegation is optimal if and only if the principal would make the same binary decision as the agent had she observed the agent ' s information. ( 2 ) providing the most informative algorithm may be suboptimal even if the principal can act on the algorithm ' s prediction. instead, the optimal algorithm may provide more information about one state and restrict information about the other. ( 3 ) well - intentioned policies aiming to provide more information, such as keeping a " human - in - the - loop " or requiring maximal prediction accuracy, could strictly worsen decision quality compared to systems with no human or no algorithmic assistance. these findings predict the underperformance of human - machine collaborations if no measures are taken to mitigate common preference misalignment between algorithms and human decision - makers.
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arxiv:2402.09384
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recently it was proposed that the standard model ( sm ) degrees of freedom reside on a $ ( 3 + 1 ) $ - dimensional wall or ` ` 3 - brane ' ' embedded in a higher - dimensional spacetime. furthermore, in this picture it is possible for the fundamental planck mass $ \ mst $ to be as small as the weak scale $ \ mst \ simeq o ( \ tev ) $ and the observed weakness of gravity at long distances is due the existence of new sub - millimeter spatial dimensions. we show that in this picture it is natural to expect neutrino masses to occur in the $ 10 ^ { - 1 } - 10 ^ { - 4 } \ ev $ range, despite the lack of any fundamental scale higher than $ \ mst $. such suppressed neutrino masses are not the result of a see - saw, but have intrinsically higher - dimensional explanations. we explore two possibilities. the first mechanism identifies any massless bulk fermions as right - handed neutrinos. these give naturally small dirac masses for the same reason that gravity is weak at long distances in this framework. the second mechanism takes advantage of the large { \ it infrared } desert : the space in the extra dimensions. here, small majorana neutrino masses are generated by breaking lepton number on distant branes.
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arxiv:hep-ph/9811448
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we propose pix2pix3d, a 3d - aware conditional generative model for controllable photorealistic image synthesis. given a 2d label map, such as a segmentation or edge map, our model learns to synthesize a corresponding image from different viewpoints. to enable explicit 3d user control, we extend conditional generative models with neural radiance fields. given widely - available monocular images and label map pairs, our model learns to assign a label to every 3d point in addition to color and density, which enables it to render the image and pixel - aligned label map simultaneously. finally, we build an interactive system that allows users to edit the label map from any viewpoint and generate outputs accordingly.
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arxiv:2302.08509
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we introduce and analyse an extension of the disjunctive sum operation on some classical impartial games. whereas the disjunctive sum describes positions formed from independent subpositions, our operation combines positions that are not completely independent but interact only in a very restricted way. we extend the games nim and silver dollar, played by moving counters along one - dimensional strips of cells, by joining several strips at their initial cell. we prove that, in certain cases, computing the sprague - grundy function can be simplified to that of a simpler game with at most two tokens in each strip. we give an algorithm that, for each sprague - grundy value g, computes the positions of two - token star nim whose sprague - grundy values are g. we establish that the sequence of differences of entries of these positions is ultimately additively periodic.
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arxiv:1702.07068
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starting from the theory of axion electrodynamics, we work out the axionic modifications to the electromagnetic casimir energy using the green ' s function, both when the axion field is initially assumed purely time - dependent and when the axion field configuration is a static domain wall. for the first case it means that the oscillating axion background is taken to resemble an axion fluid at rest in a conventional casimir setup with two infinite parallel conducting plates, while in the second case we evaluate the radiation pressure acting on an axion domain wall. we extend previous theories in order to include finite temperatures. various applications are discussed. 1. we review the theory of axion electrodynamics and particularly the energy - momentum conservation in a linear dielectric and magnetic material. we treat this last aspect by extending former results by brevik and chaichian ( 2022 ) and patkos ( 2022 ). 2. adopting the model of the oscillating axion background we discuss the axion - induced modifications to the casimir force between two parallel plates by using a green ' s function approach. 3. we calculate the radiation pressure acting on an axion domain wall at finite temperature t. our results for an oscillating axion field and a domain wall are also useful for condensed matter physics, where " axionic topological insulators " interact with the electromagnetic field with a chern - simons interaction, like the one in axion electrodynamics, and there are experimental systems analogous to time - dependent axion fields and domain walls as the ones showed by jiang, q. d., \ & wilczek, f. ( 2019 ) and fukushima et al. ( 2019 ). 4. we compare our results, where we assume time - dependent or space - dependent axion configurations, with the discussion of the optical activity of axion electrodynamics by sikivie ( 2021 ) and carrol et al. ( 1990 ).
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arxiv:2302.13129
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we are systematically analyzing asca gis data taken during the satellite attitude maneuver operation. our motivation is to search for serendipitous hard x - ray sources and make the asca slew survey catalog. during its operational life from 1993 february to 2000 july, asca carried out more than 2, 500 maneuver operations, and total exposure time during the maneuver was ~ 415 ksec after data screening. preliminary results are briefly reported.
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arxiv:astro-ph/0210683
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we made 22 observations on the small magellanic cloud ( smc ) and covered full regions by the end of the asca mission. we detected 106 discrete sources with a criterion of s / n > 5 and performed systematic analyses on all of the sources. we determined the source positions with an ~ 40 ' ' error radius ( 90 % confidence ) for sources detected in the central 20 ' radius of the gis. we detected coherent pulsations from 17 sources. among them, eight were newly discovered during this study. we classified most of these pulsars as x - ray binary pulsars ( xbps ) based on their properties, such as the flux variability and the existence of an optical counterpart. we detected x - ray emission from eight supernova remnants ( snrs ). among them, five snrs showed emission lines in their spectra, hence we regarded the five as thermal snrs. we found that xbps and thermal snrs in the smc can be clearly separated by their spectral hardness ratio. applying this empirical law to faint ( thus unclassified ) sources, we found 19 xbp candidates and four thermal snr candidates. we also found several tens of candidates for active galactic nuclei, both from the hardness ratio and the logn - - logs relation of extragalactic sources. based on these asca results and further information from other sattelites, we compiled comprehensive catalogues of discrete x - ray sources in the small magellanic cloud. using the catalogues, we derived the spatial distributions of xbps and snrs. xbps and snrs were found to be concentrated in the main body and eastern wing, which resembles the distribution of young stars with ages of ~ 2e7yr. by comparing the source populations in the smc and our galaxy, we suggest that the star - forming rate ( per unit mass ) in the smc was much higher than the galaxy 1e7yr ago. we also discuss the recent change of the star - forming rate in the smc.
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arxiv:astro-ph/0302163
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the renowned proverb, numbers do not lie, underscores the reliability and insight that lie beneath numbers, a concept of undisputed importance, especially in economics and finance etc. despite the prosperity of benford ' s law in the first digit analysis, its scope fails to remain comprehensiveness when it comes to deciphering the laws of number. this paper delves into number laws by taking the financial statements of china real estate as a representative, quantitatively study not only the first digit, but also depict the other two dimensions of numbers : frequency and length. the research outcomes transcend mere reservations about data manipulation and open the door to discussions surrounding number diversity and the delineation of the usage insights. this study wields both economic significance and the capacity to foster a deeper comprehension of numerical phenomena.
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arxiv:2309.05221
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cascades of poisson processes are probabilistic models for spatio - temporal phenomena in which ( i ) previous events may trigger subsequent events, and ( ii ) both the background and triggering processes are conditionally poisson. such phenomena are typically " data rich but knowledge poor ", in the sense that large datasets are available yet a mechanistic understanding of the background and triggering processes which generate the data are unavailable. in these settings nonparametric estimation plays a central role. however existing nonparametric estimators have computational and storage complexity $ \ mathcal { o } ( n ^ 2 ) $, precluding their application on large datasets. here, by assuming the triggering process acts only locally, we derive nonparametric estimators with computational complexity $ \ mathcal { o } ( n \ log n ) $ and storage complexity $ \ mathcal { o } ( n ) $. our approach automatically learns the domain of the triggering process from data and is essentially free from hyperparameters. the methodology is applied to a large seismic dataset where estimation under existing algorithms would be infeasible.
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arxiv:1507.03047
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in this work we analyze the power scaling potential of amplifying multicore fibers ( mcfs ) used in coherently - combined systems. in particular, in this study we exemplarily consider rod - type mcfs with 2x2 up to 10x10 ytterbium doped cores arranged in a squared pattern. we will show that, even though increasing the number of active cores will lead to higher output powers, particular attention has to be paid to arising thermal effects, which potentially degrade the performance of these systems. additionally, we analyze the influence of the core dimensions on the extractable and combinable output power and pulse energy. this includes a detailed study on the thermal effects that influence the propagating transverse modes and, in turn, the amplification efficiency, the combining efficiency, the onset of nonlinear effect, as well as differences in the optical path lengths between the cores. considering all these effects under rather extreme conditions, the study predicts that average output powers higher than 10 kw from a single 1 m long ytterbium - doped mcf are feasible and femtosecond pulses with energies higher than 400 mj can be extracted and efficiently recombined in a filled - aperture scheme.
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arxiv:2103.00978
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we analyse the security of some variants of the cfs code - based digital signature scheme. we show how the adoption of some code - based hash - functions to improve the efficiency of cfs leads to the ability of an attacker to produce a forgery compatible to the rightful user ' s public key.
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arxiv:2112.00429
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object detection is a critical part of visual scene understanding. the representation of the object in the detection task has important implications on the efficiency and feasibility of annotation, robustness to occlusion, pose, lighting, and other visual sources of semantic uncertainty, and effectiveness in real - world applications ( e. g., autonomous driving ). popular object representations include 2d and 3d bounding boxes, polygons, splines, pixels, and voxels. each have their strengths and weakness. in this work, we propose a new representation of objects based on the bivariate normal distribution. this distribution - based representation has the benefit of robust detection of highly - overlapping objects and the potential for improved downstream tracking and instance segmentation tasks due to the statistical representation of object edges. we provide qualitative evaluation of this representation for the object detection task and quantitative evaluation of its use in a baseline algorithm for the instance segmentation task.
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arxiv:1907.12929
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we have studied the low - frequency dynamics of the charge carriers in different organic charge - transfer salts $ \ kappa $ - ( bedt - ttf ) $ _ 2 $ x with polymeric anions x by using resistance noise spectroscopy. our aim is to investigate the structural, glass - like transition caused by the conformational degrees of freedom of the bedt - ttf molecules ' terminal ethylene groups. although of fundamental importance for studies of the electronic ground - state properties, the phenomenology of the glassy dynamics is only scarcely investigated and its origin is not understood. our systematic studies of fluctuation spectroscopy of various different compounds reveal a universal, pronounced maximum in the resistance noise power spectral density related to the glass transition. the energy scale of this precess can be identified with the activation energy of the glass - like ethylene endgroup structural dynamics as determined from thermodynamic and nmr measurements. for the first time for this class of ' plastic crystals ', we report a typical glassy property of the relaxation time, namely a vogel - fulcher - tammann law, and are able to determine the degree of fragility of the glassy system. supporting $ \ textit { ab initio } $ calculations provide an explanation for the origin and phenomenology of the glassy dynamics in different systems in terms of a simple two - level model, where the relevant energy scales are determined by the coupling of the ethylene endgroups to the anions.
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arxiv:1506.05191
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a biomimetic machine intelligence algorithm, that holds promise in creating invariant representations of spatiotemporal input streams is the hierarchical temporal memory ( htm ). this unsupervised online algorithm has been demonstrated on several machine - learning tasks, including anomaly detection. significant effort has been made in formalizing and applying the htm algorithm to different classes of problems. there are few early explorations of the htm hardware architecture, especially for the earlier version of the spatial pooler of htm algorithm. in this article, we present a full - scale htm architecture for both spatial pooler and temporal memory. synthetic synapse design is proposed to address the potential and dynamic interconnections occurring during learning. the architecture is interweaved with parallel cells and columns that enable high processing speed for the htm. the proposed architecture is verified for two different datasets : mnist and the european number plate font ( eunf ), with and without the presence of noise. the spatial pooler architecture is synthesized on xilinx zynq - 7, with 91. 16 % classification accuracy for mnist and 90 \ % accuracy for eunf, with noise. for the temporal memory sequence prediction, first and second order predictions are observed for a 5 - number long sequence generated from eunf dataset and 95 % accuracy is obtained. moreover, the proposed hardware architecture offers 1364x speedup over the software realization. these results indicate that the proposed architecture can serve as a digital core to build the htm in hardware and eventually as a standalone self - learning system.
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arxiv:1808.05839
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real - time or near real - time hyperspectral detection and identification are extremely useful and needed in many fields. these data sets can be quite large, and the algorithms can require numerous computations that slow the process down. a common way of speeding up the process is to use principal component analysis ( pca ) for dimension reduction. in the reduced dimensional space, provided by a subset of the principal components, fewer computations are needed to process the data resulting in a faster run time. in this paper, we propose a way to further decrease the time required to use pca by investigating how many principal components may be omitted with minimal impact on the detection rate. using ace to perform the detection, and then probability, and spectral fit for identification, we find that the number of principal components can be reduced by a substantial amount before seeing a noticeable change in detection rates.
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arxiv:2311.13779
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we search for evidence of a relation between properties of young stellar objects ( ysos ) and their parent molecular clouds to understand the initial conditions of high - mass star formation. a sample of 135 sources was selected from the infrared astronomical satellite ( iras ) point source catalog, on the basis of their red color to enhance the possibility of discovering young sources. using the kolner observatorium fur submillimeter astronomie ( kosma ) 3 - m telescope, a single - point survey in 13co ( 2 - 1 ) was carried out for the entire sample, and 14 sources were mapped further. archival mid - infrared ( mir ) data were compared with the 13co emissions to identify evolutionary stages of the sources. a 13co observed sample was assembled to investigate the correlation between 13co line width of the clouds and the luminosity of the associated ysos. we identified 98 sources suitable for star formation analyses for which relevant parameters were calculated. we detected 18 cores from 14 mapped sources, which were identified with eight pre - uc hii regions and one uc hii region, two high - mass cores earlier than pre - uc hii phase, four possible star forming clusters, and three sourceless cores. by compiling a large ( 360 sources ) 13co observed sample, a good correlation was found between the 13co line width of the clouds and the bolometric luminosity of the associated ysos, which can be fitted as a power law : lg ( dv13 / km / s ) = - 0. 023 + 0. 135lg ( lbol / lsolar ). results show that luminous ( > 10 ^ 3lsolar ) ysos tend to be associated with both more massive and more turbulent ( dv13 > 2km / s ) molecular cloud structures.
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arxiv:0909.3312
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we study thermodynamics of the schwarzschild - de sitter black hole in five dimensions by introducing two temperatures based on the standard and bousso - hawking normalizations. we use the first - law of thermodynamics to derive thermodynamic quantities. the two temperatures indicate that the nariai black hole is thermodynamically unstable. however, it seems that black hole thermodynamics favors the standard normalization, and does not favor the bousso - hawking normalization.
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arxiv:0712.3315
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within the framework of a constituent quark model, we investigate the heavy quark conserving weak decays of $ \ xi _ c $ and $ \ xi _ b $. this process involves elementary transitions of $ us \ to du $ or $ s \ to ud \ bar u $ with the heavy quark as a spectator, while for the charmed baryon in the initial state it can also occur via $ cs \ to dc $ to conserve the heavy quark flavor in the weak decays. it shows that the heavy quark symmetry ( hqs ) plays an essential role in the processes where the heavy quark acts as a spectator. for the $ \ xi _ c $ decays, the dominance of the pole terms in the parity - conserving transitions is evident. this can naturally explain the sizeable branching ratio for $ \ xi _ c ^ 0 \ to \ lambda _ c \ pi ^ - $ as recently reported by lhcb. the same mechanism predicts a large branching ratio for $ \ xi _ c ^ + \ to \ lambda _ c \ pi ^ 0 $. in contrast, the decays of $ \ xi _ b $ will only go through the parity - violating processes because of the hqs. in addition, the branching ratios of the $ \ xi _ c ^ + \ to \ lambda _ c \ pi ^ 0 $ and $ \ xi _ b ^ 0 \ to \ lambda _ b \ pi ^ 0 $ processes are also predicted for the further experimental measurement.
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arxiv:2111.14111
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we introduce the new class of submanifolds of co - banach type in tame fr \ ' echet manifolds and construct tame fr \ ' echet submanifolds as inverse images of regular values of certain tame maps. our method furnishes an easy way to construct tame fr \ ' echet manifolds. the results presented are key ingredients in the construction of affine kac - moody symmetric spaces ; they have also important applications in the study of isoparametric submanifolds in tame fr \ ' echet spaces.
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arxiv:1305.3145
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highway traffic states data collected from a network of sensors can be considered a high - dimensional nonlinear dynamical system. in this paper, we develop a novel data - driven method - - anti - circulant dynamic mode decomposition with sparsity - promoting ( circdmdsp ) - - to study the dynamics of highway traffic speed data. particularly, circdmdsp addresses several issues that hinder the application of existing dmd models : limited spatial dimension, presence of both recurrent and non - recurrent patterns, high level of noise, and known mode stability. the proposed circdmdsp framework allows us to numerically extract spatial - temporal coherent structures with physical meanings / interpretations : the dynamic modes reflect coherent spatial bases, and the corresponding temporal patterns capture the temporal oscillation / evolution of these dynamic modes. our result based on seattle highway loop detector data showcases that traffic speed data is governed by a set of periodic components, e. g., mean pattern, daily pattern, and weekly pattern, and each of them has a unique spatial structure. the spatiotemporal patterns can also be used to recover / denoise observed data and predict future values at any timestamp by extrapolating the temporal vandermonde matrix. our experiments also demonstrate that the proposed circdmdsp framework is more accurate and robust in data reconstruction and prediction than other dmd - based models.
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arxiv:2302.07108
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creation science in public schools in the united states effectively ended in 1987 following the united states supreme court decision in edwards v. aguillard. the court affirmed that a statute requiring the teaching of creation science alongside evolution when evolution is taught in louisiana public schools was unconstitutional because its sole true purpose was to advance a particular religious belief. in response to this ruling, drafts of the creation science school textbook of pandas and people were edited to change references of creation to intelligent design before its publication in 1989. the intelligent design movement promoted this version. requiring intelligent design to be taught in public school science classes was found to be unconstitutional in the 2005 kitzmiller v. dover area school district federal court case. = = = before 1960s = = = the teaching of evolution was gradually introduced into more and more public high school textbooks in the united states after 1900, but in the aftermath of the first world war the growth of fundamentalist christianity gave rise to a creationist opposition to such teaching. legislation prohibiting the teaching of evolution was passed in certain regions, most notably tennessee ' s butler act of 1925. the soviet union ' s successful launch of sputnik 1 in 1957 sparked national concern that the science education in public schools was outdated. in 1958, the united states passed national defense education act which introduced new education guidelines for science instruction. with federal grant funding, the biological sciences curriculum study ( bscs ) drafted new standards for the public schools ' science textbooks which included the teaching of evolution. almost half the nation ' s high schools were using textbooks based on the guidelines of the bscs soon after they were published in 1963. the tennessee legislature did not repeal the butler act until 1967. creation science ( dubbed " scientific creationism " at the time ) emerged as an organized movement during the 1960s. it was strongly influenced by the earlier work of armchair geologist george mccready price who wrote works such as illogical geology : the weakest point in the evolution theory ( 1906 ) and the new geology ( 1923 ) to advance what he termed " new catastrophism " and dispute the current geological time frames and explanations of geologic history. price was cited at the scopes trial of 1925, but his writings had no credence among geologists and other scientists. price ' s " new catastrophism " was also disputed by most other creationists until its revival with the 1961 publication of the genesis flood by john c. whitcomb and henry m. morris, a work which quickly became an important text on the issue to fundamentalist christians and expanded the field
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https://en.wikipedia.org/wiki/Creation_science
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we speculate about the spacetime description due to the presence of lorentzian wormholes ( handles in spacetime joining two distant regions or other universes ) in quantum gravity. the semiclassical rate of production of these lorentzian wormholes in reissner - nordstr \ " om spacetimes is calculated as a result of the spontaneous decay of vacuum due to a real tunneling configuration. in the magnetic case it only depends on the field theoretical fine structure constant. we predict that the quantum probability corresponding to the nucleation of such geodesically complete spacetimes should be actually negligible in our physical universe.
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arxiv:gr-qc/9703017
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the open radio access network ( open ran ) framework, emerging as the cornerstone for artificial intelligence ( ai ) - enabled sixth - generation ( 6g ) mobile networks, heralds a transformative shift in radio access network architecture. as the adoption of open ran accelerates, ensuring its security becomes critical. the ran intelligent controller ( ric ) plays a central role in open ran by improving network efficiency and flexibility. nevertheless, it also brings about potential security risks that need careful scrutiny. therefore, it is imperative to evaluate the current state of ric security comprehensively. this assessment is essential to gain a profound understanding of the security considerations associated with ric. this survey combines a comprehensive analysis of ran security, tracing its evolution from 2g to 5g, with an in - depth exploration of ric security, marking the first comprehensive examination of its kind in the literature. real - world security incidents involving ric are vividly illustrated, providing practical insights. the study evaluates the security implications of the ric within the 6g open ran context, addressing security vulnerabilities, mitigation strategies, and potential enhancements. it aims to guide stakeholders in the telecom industry toward a secure and dependable telecommunications infrastructure. the article serves as a valuable reference, shedding light on the ric ' s crucial role within the broader network infrastructure and emphasizing security ' s paramount importance. this survey also explores the promising security opportunities that the ric presents for enhancing network security and resilience in the context of 6g mobile networks. it outlines open issues, lessons learned, and future research directions in the domain of intelligent control in 6g open ran, facilitating a comprehensive understanding of this dynamic landscape.
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arxiv:2405.08577
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loosely speaking, the navier - stokes - $ \ alpha $ model and the navier - stokes equations differ by a spatial filtration parametrized by a scale denoted $ \ alpha $. starting from a strong two - dimensional solution to the navier - stokes - $ \ alpha $ model driven by a multiplicative noise, we demonstrate that it generates a strong solution to the stochastic navier - stokes equations under the condition $ \ alpha $ goes to 0. the initially introduced probability space and the wiener process are maintained throughout the investigation, thanks to a local monotonicity property that abolishes the use of skorokhod ' s theorem. high spatial regularity a priori estimates for the fluid velocity vector field are carried out within periodic boundary conditions.
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arxiv:2210.02232
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the connection between quantum optical nonclassicality and the violation of bell ' s inequalities is explored. bell type inequalities for the electromagnetic field are formulated for general states of quantised radiation and their violation is connected to other nonclassical properties of the field. this is achieved by considering states with an arbitrary number of photons and carefully identifying the hermitian operators whose expectation values do not admit any local hidden variable description. we relate the violation of these multi - photon inequalities to properties of phase space distribution functions such as the diagonal coherent state distribution function and the wigner function. finally, the family of 4 - mode states with gaussian wigner distributions is analysed, bringing out in this case the connection of violation of bell type inequalities with the nonclassical property of squeezing.
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arxiv:quant-ph/9806049
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this paper investigates the concept of self - dual convolutional code. we derive the basic properties of this interesting class of codes and we show how some of the techniques to construct self - dual linear block codes generalize to self - dual convolutional codes. as for self - dual linear block codes we are able to give a complete classification for some small parameters.
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arxiv:2208.04087
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the lie algebra of feynman graphs gives rise to two natural representations, acting as derivations on the commutative hopf algebra of feynman graphs, by creating or eliminating subgraphs. insertions and eliminations do not commute, but rather establish a larger lie algebra of derivations which we here determine.
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arxiv:hep-th/0201157
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we introduce dynamic deep neural networks ( d2nn ), a new type of feed - forward deep neural network that allows selective execution. given an input, only a subset of d2nn neurons are executed, and the particular subset is determined by the d2nn itself. by pruning unnecessary computation depending on input, d2nns provide a way to improve computational efficiency. to achieve dynamic selective execution, a d2nn augments a feed - forward deep neural network ( directed acyclic graph of differentiable modules ) with controller modules. each controller module is a sub - network whose output is a decision that controls whether other modules can execute. a d2nn is trained end to end. both regular and controller modules in a d2nn are learnable and are jointly trained to optimize both accuracy and efficiency. such training is achieved by integrating backpropagation with reinforcement learning. with extensive experiments of various d2nn architectures on image classification tasks, we demonstrate that d2nns are general and flexible, and can effectively optimize accuracy - efficiency trade - offs.
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arxiv:1701.00299
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we have observed a stellar occultation of gsc5249 - 01240 by saturn ' s north polar region on november 20, 1995 from nasa ' s infrared telescope facility ( irtf ). this is the first recorded occultation by the polar region of a giant planet. the occulted region extends 88 km in vertical height and 660 km in horizontal length, over a region from 82. 5 to 85 degrees in planetocentric latitude and from 20 to 30 degrees in planetocentric longitude. based on isothermal model fits to the light curve, we find an equivalent temperature of 130 \ pm 10 k at a pressure level of 1. 6 \ pm 0. 1 \ mubar, which corresponds to a half - light latitude of 83. 2 \ pm 0. 2 degrees and longitude of 24. 1 \ pm 0. 5 degrees. using numerical inversion procedures, we have retrieved the temperature profile of the occulted region, which suggests an increase in temperature ( with radius ) of 14. 5 k between 6 and 10 \ mubar. we also find temperature fluctuations of 1 to 5 k along the path probed by the occultation ; if the observed temperature gradients of these fluctuations apply to the vertical direction only, then this region is super - adiabatic. more likely these thermal gradients are due to a combination of diffractive scintillations and horizontal temperature variations. given that isothermal model fits and numerical inversions cannot separate individual contributions to observed temperature fluctuations, such as from vertical variations, horizontal variations, and scintillations, this occultation requires a further study.
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arxiv:astro-ph/9712122
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the energy spectrum of the cosmic microwave background ( cmb ) allows constraining episodes of energy release in the early universe. in this paper we revisit and refine the computations of the cosmological thermalization problem. for this purpose a new code, called cosmotherm, was developed that allows solving the coupled photon - electron boltzmann equation in the expanding, isotropic universe for small spectral distortion in the cmb. we explicitly compute the shape of the spectral distortions caused by energy release due to ( i ) annihilating dark matter ; ( ii ) decaying relict particles ; ( iii ) dissipation of acoustic waves ; and ( iv ) quasi - instantaneous heating. we also demonstrate that ( v ) the continuous interaction of cmb photons with adiabatically cooling non - relativistic electrons and baryons causes a negative mu - type cmb spectral distortion of di _ nu / i _ nu ~ 10 ^ { - 8 } in the ghz spectral band. we solve the thermalization problem including improved approximations for the double compton and bremsstrahlung emissivities, as well as the latest treatment of the cosmological recombination process. at redshifts z < ~ 10 ^ 3 the matter starts to cool significantly below the temperature of the cmb so that at very low frequencies free - free absorption alters the shape of primordial distortions significantly. in addition, the cooling electrons down - scatter cmb photons introducing a small late negative y - type distortion at high frequencies. we also discuss our results in the light of the recently proposed cmb experiment pixie, for which cosmotherm should allow detailed forecasting. our current computations show that for energy injection because of ( ii ) and ( iv ) pixie should allow to improve existing limits, while the cmb distortions caused by the other processes seem to remain unobservable with the currently proposed sensitivities and spectral bands of pixie.
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arxiv:1109.6552
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we describe the relationship between two spaces associated to a quiver with potential. the first is a complex manifold parametrizing bridgeland stability conditions on a triangulated category, and the second is a cluster variety with a natural poisson structure. for quivers of type $ a $, we construct a local biholomorphism from the space of stability conditions to the cluster variety. the existence of this map follows from results of sibuya in the classical theory of ordinary differential equations.
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arxiv:1710.06505
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it is argued that the general four - dimensional extremal kerr - newman - ads - ds black hole is holographically dual to a ( chiral half of a ) two - dimensional cft, generalizing an argument given recently for the special case of extremal kerr. specifically, the asymptotic symmetries of the near - horizon region of the general extremal black hole are shown to be generated by a virasoro algebra. semiclassical formulae are derived for the central charge and temperature of the dual cft as functions of the cosmological constant, newton ' s constant and the black hole charges and spin. we then show, assuming the cardy formula, that the microscopic entropy of the dual cft precisely reproduces the macroscopic bekenstein - hawking area law. this cft description becomes singular in the extreme reissner - nordstrom limit where the black hole has no spin. at this point a second dual cft description is proposed in which the global part of the u ( 1 ) gauge symmetry is promoted to a virasoro algebra. this second description is also found to reproduce the area law. various further generalizations including higher dimensions are discussed.
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arxiv:0811.4393
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the general poincar \ ' e gauge cosmology given by a nine - parameter gravitational lagrangian with ghost - and tachyon - free conditions is studied from the perspective of field theory. by introducing new variables for replacing two ( pseudo - ) scalar torsions, the poincar \ ' e gauge cosmological system can be recast into a gravitational system coupled to two - scalar fields with a potential up to quartic - order. we discussed the possibility of this system producing two types of inflation without any extra inflatons. the hybrid inflation with a first - order phase transition can be ruled out, while the slow rollover can be achieved. the numerical analysis shows that the two - scalar fields system evolved in a potential well processes spontaneously four stages : " pre - inflation ", slow - roll inflation with large enough e - folds, " pre - reheating " and reheating. we also studied the stableness of this system by setting large values of initial kinetic energies. the results show that even if the system evolves past the highest point of the potential well, the scalar fields can still return to the potential well and cause inflation. the general poincar \ ' e gauge cosmology provides us with a self - consistent candidate of inflation.
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arxiv:1906.04340
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an introductory review of classical statistical mechanics
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arxiv:cond-mat/0504790
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the increasing cosmic ray statistics collected by present experiments and the future prospects with new large arrays demand accurate calculations of the extensive air shower parameters. the energy of the primary particle is estimated by ground arrays fitting a lateral distribution function ( ldf ) to the particle densities at a given observing level. however, the lack of appropriate parameterization for these distributions, able to reproduce the data collected from all arrival directions, makes it difficult the experimental analysis. starting from analytical ldf for vertical showers we study the atmospheric depth dependence of the shower parameters, which is necessary to obtain the corresponding particle density distributions for inclined showers. in our approach both geometrical and atmospheric attenuation effects producing a lateral asymmetry in non - vertical showers are included. the resulting electron and muon ldf fit very well the monte carlo simulated data at all zenith angles.
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arxiv:astro-ph/0110237
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bipolar disorder ( bd ) and borderline personality disorder ( bpd ) are two chronic mental health conditions that clinicians find challenging to distinguish based on clinical interviews, due to their overlapping symptoms. in this work, we investigate the automatic detection of these two conditions by modelling both verbal and non - verbal cues in a set of interviews. we propose a new approach of modelling short - term features with visibility - signature transform, and compare it with widely used high - level statistical functions. we demonstrate the superior performance of our proposed signature - based model. furthermore, we show the role of different sets of features in characterising bd and bpd.
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arxiv:2102.09607
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we describe an effective field theory for atomic lasers which reduces to the jaynes - cummings model in the non - relativistic, single mode limit. our action describes a multi - mode system, with general polarizations and lorentz invariance and can therefore be used in all contexts from the astrophysical to the laboratory. we show how to compute the effective action for this model and perform the calculation explicitly at the one loop level. our model provides a way of analyzing a many - particle, two - state model with arbitrary boundary conditions.
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arxiv:quant-ph/9703015
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a binary code with covering radius $ r $ is a subset $ c $ of the hypercube $ q _ n = \ { 0, 1 \ } ^ n $ such that every $ x \ in q _ n $ is within hamming distance $ r $ of some codeword $ c \ in c $, where $ r $ is as small as possible. for a fixed coordinate $ i \ in [ n ] $, define $ c ( b, i ) $, for $ b = 0, 1 $, to be the set of codewords with a $ b $ in the $ i $ th position. then $ c $ is normal if there exists an $ i \ in [ n ] $ such that for any $ v \ in q _ n $, the sum of the hamming distances from $ v $ to $ c ( 0, i ) $ and $ c ( 1, i ) $ is at most $ 2r + 1 $. we newly define what it means for an asymmetric covering code to be normal, and consider the worst case asymptotic densities $ \ nu ^ * ( r ) $ and $ \ nu ^ * _ + ( r ) $ of constant radius $ r $ symmetric and asymmetric normal covering codes, respectively. using a probabilistic deletion method, and analysis adapted from previous work by krivelevich, sudakov, and vu, we show that both are bounded above by $ e ( r \ log r + \ log r + \ log \ log r + 4 ) $, giving evidence that minimum size constant radius covering codes could still be normal.
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arxiv:math/0409171
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we explore the possibilities of enforcing and preventing consensus in continuous opinion dynamics that result from modifications in the communication rules. we refer to the model of weisbuch and deffuant, where $ n $ agents adjust their continuous opinions as a result of random pairwise encounters whenever their opinions differ not more than a given bound of confidence $ \ eps $. a high $ \ eps $ leads to consensus, while a lower $ \ eps $ leads to a fragmentation into several opinion clusters. we drop the random encounter assumption and ask : how small may $ \ eps $ be such that consensus is still possible with a certain communication plan for the entire group? mathematical analysis shows that $ \ eps $ may be significantly smaller than in the random pairwise case. on the other hand we ask : how large may $ \ eps $ be such that preventing consensus is still possible? in answering this question we prove fortunato ' s simulation result that consensus cannot be prevented for $ \ eps > 0. 5 $ for large groups. % next we consider opinion dynamics under different individual strategies and examine their power to increase the chances of consensus. one result is that balancing agents increase chances of consensus, especially if the agents are cautious in adapting their opinions. however, curious agents increase chances of consensus only if those agents are not cautious in adapting their opinions.
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arxiv:0708.3244
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an " expanded " description is introduced to examine the spinor - monopole identification proposed by strassler for four - dimensional $ \ cal n $ = 1 supersymmetric spin ( 10 ) gauge theories with matter in f vector and n spinor representations. it is shown that a z _ 2 monopole in the " expanded " theory is associated with massive spinors of the spin ( 10 ) theory. for n = 2, two spinor case, we confirm this identification by matching the transformation properties of the two theories under su ( 2 ) flavor symmetry. however, for n $ \ ge $ 3, the transformation properties are not matched between the spinors and the monopole. this disagreement might be due to the fact that the su ( n ) flavor symmetry of the spin ( 10 ) theory is partially realized as an su ( 2 ) symmetry in the " expanded " theory.
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arxiv:hep-th/9710213
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in this work, we obtain the numerical temperature field to a thermally developing fluid flow inside parallel plates problem with a quantum computing method. the physical problem deals with the heat transfer of a steady state, hydrodinamically developed and thermally developing fluid flow inside two parallel plates channel subjected to a prescribed constant heat flux. its solution is formulated numerically with finite differences method, where a sequence of linear systems must be solved in order to determine the complete temperature field. such linear systems are written as discrete unconstrained optimization problems with floating points being approximated using binary variables and solved using near - term quantum heuristics. due to the exponential cost of simulating quantum algorithms, a reduced number of qubits had to be used in the simulations, causing a loss of precision in the results. however, this work advances the state of the art of solutions of differential equations with noisy quantum devices and could be used for useful applications when quantum computers with thousands of qubits become available.
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arxiv:2208.05805
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we prove a new, tight upper bound on the number of incidences between points and hyperplanes in euclidean d - space. given n points, of which k are colored red, there are o _ d ( m ^ { 2 / 3 } k ^ { 2 / 3 } n ^ { ( d - 2 ) / 3 } + kn ^ { d - 2 } + m ) incidences between the k red points and m hyperplanes spanned by all n points provided that m = \ omega ( n ^ { d - 2 } ). for the monochromatic case k = n, this was proved by agarwal and aronov. we use this incidence bound to prove that a set of n points, no more than n - k of which lie on any plane or two lines, spans \ omega ( nk ^ 2 ) planes. we also provide an infinite family of counterexamples to a conjecture of purdy ' s on the number of hyperplanes spanned by a set of points in dimensions higher than 3, and present new conjectures not subject to the counterexample.
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arxiv:1006.3878
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the large class of inflationary models known as $ \ alpha $ - and $ \ xi $ - attractors gives identical cosmological predictions at tree level ( at leading order in inverse power of the number of efolds ). working with the renormalization group improved action, we show that these predictions are robust under quantum corrections. this means that for all the models considered the inflationary parameters $ ( n _ s, r ) $ are ( nearly ) independent on the renormalization group flow. the result follows once the field dependence of the renormalization scale, fixed by demanding the leading log correction to vanish, satisfies a quite generic condition. in higgs inflation ( which is a particular $ \ xi $ - attractor ) this is indeed the case ; in the more general attractor models this is still ensured by the renormalizability of the theory in the effective field theory sense.
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arxiv:1611.04997
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the central limit theorem does not hold for strongly correlated stochastic variables, as is the case for statistical systems close to criticality. recently, the calculation of the probability distribution function ( pdf ) of the magnetization mode has been performed with the functional renormalization group in the case of the three - dimensional ising model [ balog et al., phys. rev. lett. { \ bf 129 }, 210602 ( 2022 ) ]. it has been shown in that article that there exists an entire family of universal pdfs parameterized by $ \ zeta = \ lim _ { l, \ xi _ \ infty \ rightarrow \ infty } l / \ xi _ \ infty $ which is the ratio of the system size $ l $ to the bulk correlation length $ \ xi _ { \ infty } $ with both the thermodynamic limit and the critical limit being taken simultaneously. we show how these pdfs or, equivalently, the rate functions which are their logarithm, can be systematically computed perturbatively in the $ \ epsilon = 4 - d $ expansion. we determine the whole family of universal pdfs and show that they are in good qualitative agreement with monte carlo data. finally, we conjecture on how to significantly improve the quantitative agreement between the one - loop and the numerical results.
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arxiv:2407.12603
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we present $ bvi $ surface photometry of 31 dwarf galaxy candidates discovered in a deep image stack from the kmtnet supernova program of $ \ sim $ 30 square degrees centered on the nearby ngc 2784 galaxy group. our final images have a 3 $ \ sigma $ surface brightness detection limit of $ \ mu _ v \ approx 28. 5 $ mag arcsec $ ^ { - 2 } $. the faintest central surface brightness that we measure is $ \ mu _ { 0, v } = 26. 1 $ mag arcsec $ ^ { - 2 } $. if these candidates are at the distance of ngc 2784, then they have absolute magnitudes greater than $ m _ v = - 9. 5 $ mag and effective radii larger than 170 pc. their radial number density decreases exponentially with distance from the center of ngc 2784 until it flattens beyond a radius of 0. 5 mpc. we interpret the baseline density level to represent the background contamination and so estimate that 22 of the 31 new candidates are dwarf members of the group. the candidate ' s average color, $ \ langle ( b - v ) _ 0 \ rangle \ approx 0. 7 $, and sersic structural parameters are consistent with those parameters for the dwarf populations of other groups. we find that the central population of dwarfs is redder and brighter than the rest of the population. the measured faint end slope of the luminosity function, $ \ alpha \ approx - 1. 33 $, is steeper than that of the local group but consistent with published results for other groups. such comparisons are complicated by systematic differences among different studies, but will be simpler when the kmtnet survey, which will provide homogenous data for 15 to 20 groups, is completed.
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arxiv:1708.07326
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we present a high magnetic field study of electron spin waves in atomic hydrogen gas compressed to high densities of 10 ^ 18 cm ^ - 3 at temperatures ranging from 0. 26 to 0. 6 k. we observed a variety of spin wave modes caused by the identical spin rotation effect with strong dependence on the spatial profile of the polarizing magnetic field. we demonstrate confinement of these modes in regions of strong magnetic field and manipulate their spatial distribution by changing the position of the field maximum.
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arxiv:1112.3775
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monte carlo simulations away from half - filling suffer from a sign problem that can be reduced by deforming the contour of integration. such a transformation, which induces a jacobian determinant in the boltzmann weight, can be implemented using neural networks. this additional determinant cost for a generic neural network scales cubically with the volume, preventing large - scale simulations. we implement a new architecture, based on complex - valued affine coupling layers, which reduces this to linear scaling. we demonstrate the efficacy of this method by successfully applying it to systems of different size, the largest of which is intractable by other monte carlo methods due to its severe sign problem.
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arxiv:2203.00390
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in august 2023, the long - planned discharging of radioactive wastewater from the fukushima dai - ichi nuclear power plant ( fdnpp ) started after the confirmation of its feasibility and safety. as this water contains elevated amounts of tritium even after being diluted, a lot of resources have been invested in the monitoring of the fukushima coastal region where the discharge outlet is located. we compare the first $ ^ 3 $ h surface activity concentrations from these measurements ( up to the end of november 2023 ) with the available background values to evaluate a possible impact of the long - term discharging on humans and environmental levels of the radionuclide of interest in the same or nearby area. from our results, we can conclude that the joint effect of horizontal and vertical mixing has been significant enough to reduce tritium concentrations at the monitored locations in the region close to the fdnpp port two days after the end of the respective phase of the discharging beyond the detection limit of the applied analytical methods ( ~ 0. 3 bq l $ ^ { - 1 } $ ) which is by five orders of magnitude lower than safety limit for drinking water set by the world health organization ( who ). moreover, the distant correlation analysis showed that tritium concentrations at stations located further than 1. 4 km were very close to pre - discharge levels ( ~ 0. 4 bq l $ ^ { - 1 } $ ). we also estimated that the $ ^ 3 $ h activity concentration in the offshore fukushima region would be elevated by 0. 01 bq l $ ^ { - 1 } $ at maximum over a year of continuous discharging, which is in concordance with the already published modelling papers and much less than the impact of the fdnpp accident in 2011.
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arxiv:2407.18664
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simplified assumptions about the thermodynamics of the electrons are normally employed in general - relativistic magnetohydrodynamic ( grmhd ) simulations of accretion onto black holes. to counter this, we have developed a self - consistent approach to study magnetised and radiatively cooled two - temperature accretion flows around a kerr black hole in two spatial dimensions. the approach includes several heating processes, radiative cooling, and a coupling between the electrons and the ions via coulomb interaction. we test our approach by performing axisymmetric grmhd simulations of magnetised tori accreting onto a kerr black hole under various astrophysical scenarios. in this way, we find that the inclusion of the coulomb interaction and the radiative cooling impacts the thermodynamical properties of both the ions and electrons, changing significantly the temperature distribution of the latter, and underlining the importance of a two - temperature approach when imaging these flows. in addition, we find that the accretion rate influences the bulk properties of the flow as well as the thermodynamics of the electrons and ions. interestingly, we observe qualitatively distinct temperature properties for sane and mad accretion modes while maintaining the same accretion rates, which could help distinguishing mad and sane accretion flows via observations. finally, we propose two new relations for the temperature ratios of the electrons, ions, and of the gas in terms of the plasma - $ \ beta $ parameter. the new relations represent a simple and effective approach to treat two - temperature accretion flows on supermassive black holes such as sgr a * and m \, 87 *.
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arxiv:2206.13184
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we extract experimentally the electronic thermal conductivity, $ k _ { e } $, in suspended graphene which we dope using a back - gate electrode. we make use of two - point dc electron transport at low bias voltages and intermediate temperatures ( 50 - 160 k ), where the electron and lattice temperatures are decoupled. the thermal conductivity is proportional to the charge conductivity times the temperature, confirming that the wiedemann - franz relation is obeyed in suspended graphene. we extract an estimate of the lorenz coefficient as 1. 1 to 1. 7 $ \ times 10 ^ { - 8 } $ w $ \ omega $ k $ ^ { - 2 } $. $ k _ e $ shows a transistor effect and can be tuned with the back - gate by more than a factor of 2 as the charge carrier density ranges from $ \ approx $ 0. 5 to 1. 8 $ \ times 10 ^ { 11 } $ cm $ ^ { - 2 } $.
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arxiv:1401.3030
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we present a simplified expression for the gravitational angular momentum in the framework of the teleparallel equivalent of general relativity ( tegr ). the expression arises from the constraints equations of the hamiltonian formulation of the tegr. we apply this expression to the calculation of the angular momentum of plane - fronted gravitational waves in an arbitrary three - dimensional volume $ v $ of space and compare the results with those obtained for linearised gravitational waves.
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arxiv:1402.5344
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