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we study the periodic potential of one - dimensional optical lattice originated from scalar shift and vector shift by manipulating the lattice polarizations. the ac stark shift of optical lattice is measured by kapitza - dirac scattering of $ ^ { 87 } $ rb bose - einstein condensate and the characteristics of spin - dependent optical lattice are presented by scanning the lattice wavelength between the d1 and d2 lines. at the same time, tune - out wavelengths that ac stark shift cancels can be probed by optical lattice. we give the tune - out wavelengths in more general cases of balancing the contributions of both the scalar and vector shift. our results provide a clear interpretation for spin - dependent optical lattice and tune - out wavelengths, and help to design it by choosing the appropriate lattice wavelength. | arxiv:2109.05670 |
a box in euclidean $ k $ - space is the cartesian product of $ k $ closed intervals on the real line. the boxicity of a graph $ g $, denoted by $ \ text { box } ( g ) $, is the minimum nonnegative integer $ k $ such that $ g $ can be isomorphic to the intersection graph of a family of boxes in euclidean $ k $ - space. in this paper, we present a sufficient condition for a graph $ g $ under which $ \ text { box } ( g ) \ leq \ chi ( g ) $ holds, where $ \ chi ( g ) $ denotes the chromatic number of $ g $. bhowmick and chandran ( 2010 ) proved that $ \ text { box } ( g ) \ leq \ chi ( g ) $ holds for a graph $ g $ with no asteroidal triples. we prove that $ \ text { box } ( g ) \ leq \ chi ( g ) $ holds for a graph $ g $ in a special family of circulant graphs with an asteroidal triple. | arxiv:1711.08261 |
dust properties are very likely affected by the environment in which dust grains evolve. for instance, some analyses of cold clumps ( 7 k - 17 k ) indicate that the aggregation process is favored in dense environments. however, studying warm ( 30 k - 40 k ) dust emission at long wavelength ( $ \ lambda $ $ > $ 300 $ \ mu $ m ) has been limited because it is difficult to combine far infared - to - millimeter ( fir - to - mm ) spectral coverage and high angular resolution for observations of warm dust grains. using herschel data from 70 to 500 $ \ mu $ m, which are part of the herschel infrared galactic ( hi - gal ) survey combined with 1. 1 mm data from the bolocam galactic plane survey ( bgps ), we compared emission in two types of environments : ultra - compact hii ( uchii ) regions, and cold molecular clumps ( denoted as cold clumps ). with this comparison we tested dust emission models in the fir - to - mm domain that reproduce emission in the diffuse medium, in these two environments ( uchii regions and cold clumps ). we also investigated their ability to predict the dust emission in our galaxy. we determined the emission spectra in twelve uchii regions and twelve cold clumps, and derived the dust temperature ( t ) using the recent two - level system ( tls ) model with three sets of parameters and the so - called t - $ \ beta $ ( temperature - dust emissvity index ) phenomenological models, with $ \ beta $ set to 1. 5, 2 and 2. 5. we tested the applicability of the tls model in warm regions for the first time. this analysis indicates distinct trends in the dust emission between cold and warm environments that are visible through changes in the dust emissivity index. however, with the use of standard parameters, the tls model is able to reproduce the spectral behavior observed in cold and warm regions, from the change of the dust temperature alone, whereas a t - $ \ beta $ model requires $ \ beta $ to be known. | arxiv:1409.6892 |
virtual try - on attracts increasing research attention as a promising way for enhancing the user experience for online cloth shopping. though existing methods can generate impressive results, users need to provide a well - designed reference image containing the target fashion clothes that often do not exist. to support user - friendly fashion customization in full - body portraits, we propose a multi - modal interactive setting by combining the advantages of both text and texture for multi - level fashion manipulation. with the carefully designed fashion editing module and loss functions, fashiontex framework can semantically control cloth types and local texture patterns without annotated pairwise training data. we further introduce an id recovery module to maintain the identity of input portrait. extensive experiments have demonstrated the effectiveness of our proposed pipeline. | arxiv:2305.04451 |
it is already known from phenomenological studies that in exclusive deep - inelastic scattering off nuclei there appears to be a scaling behavior of vector meson production cross section in both nuclear mass number, $ a $, and photon virtuality, $ q ^ { 2 } $, which is strongly modified due to gluon saturation effects. in this work we continue those studies in a realistic setup based upon using the monte carlo event generator sar { \ em t } re. we make quantitative predictions for the kinematics of the electron - ion collider, focusing on this $ a $ and $ q ^ { 2 } $ scaling picture, along with establishing a small region of squared momentum transfer, $ t $, where there are signs of this scaling that may potentially be observed at the eic. our results are represented as pseudo - data of vector meson production diffractive cross section and / or their ratios, which are obtained by parsing data collected by the event generator through smearing functions, emulating the proposed detector resolutions for the future eic. | arxiv:2202.05981 |
{ t } } { d \ varepsilon _ { n } } } { \ frac { 1 } { 1 + \ varepsilon _ { n } } } - { \ frac { \ sigma _ { t } } { ( 1 + \ varepsilon _ { n } ) ^ { 2 } } } \ end { aligned } } } substituting for the true stress β nominal strain gradient ( at the onset of necking ) : d Ο n d Ξ΅ n = Ο t 1 + Ξ΅ n 1 1 + Ξ΅ n β Ο t ( 1 + Ξ΅ n ) 2 = 0 { \ displaystyle { \ frac { d \ sigma _ { n } } { d \ varepsilon _ { n } } } = { \ frac { \ sigma _ { t } } { 1 + \ varepsilon _ { n } } } { \ frac { 1 } { 1 + \ varepsilon _ { n } } } - { \ frac { \ sigma _ { t } } { ( 1 + \ varepsilon _ { n } ) ^ { 2 } } } = 0 } this condition can also be seen in the two figures. since many stress - strain curves are presented as nominal plots, and this is a simple condition that can be identified by visual inspection, it is in many ways the easiest criterion to use to establish the onset of necking. it also corresponds to the β strength β ( ultimate tensile stress ), at least for metals that do neck ( which covers the majority of β engineering β metals ). on the other hand, the peak in a nominal stress - strain curve is commonly a fairly flat plateau, rather than a sharp maximum, so accurate assessment of the strain at the onset of necking may be difficult. nevertheless, this strain is a meaningful indication of the β ductility β of the metal β more so than the commonly - used β nominal strain at fracture β, which depends on the aspect ratio of the gauge length of the tensile test - piece β see the article on ductility. = = = application to polymers = = = the tangent construction shown above is rarely used in interpreting the stress - strain curves of metals. however, it is popular for analysis of the tensile drawing of polymers. ( since it allows study of the regime of stable necking ). it may be noted that, for polymers, the strain is commonly expressed as a β draw ratio β, rather than a strain : | https://en.wikipedia.org/wiki/Necking_(engineering) |
we present in this work a generalization of the solution of gorenstein and yang to the inconsistency problem of thermodynamics for systems of quasi - particles whose masses depend on both the temperature and the chemical potential. we work out several solutions for an interacting system of quarks and gluons and show that there is only one type of solution that reproduce both perturbative and lattice qcd. | arxiv:0905.0667 |
last year i talked at this meeting about a possible time dependence of the qcd coupling constant $ \ alpha _ s $. this year i shall look into the problem once more, without fully repeating the arguments given last year. astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of grand unification. a variation of the electromagnetic coupling constant could either be generated by a corresponding time variation of the unified coupling constant or by a time variation of the unification scale, or by both. the various possibilities, differing substantially in their implications for the variation of low energy physics parameters like the nuclear mass scale, are discussed. the case in which the variation is caused by a time variation of the unification scale is of special interest. it is supported in addition by recent hints towards a time change of the proton - electron mass ratio. | arxiv:hep-ph/0407068 |
we discuss electric dipole moments ( edms ) in the framework of cp - violating natural supersymmetry ( susy ). recent experimental results have significantly tightened constraints on the edms of electrons and of mercury, and substantial further progress is expected in the near future. we assess how these results constrain the parameter space of natural susy. in addition to our discussion of susy, we provide a set of general formulas for two - loop fermion edms, which can be applied to a wide range of models of new physics. in the susy context, the two - loop effects of stops and charginos respectively constrain the phases of $ a _ t \ mu $ and $ m _ 2 \ mu $ to be small in the natural part of parameter space. if the higgs mass is lifted to 125 gev by a new tree - level superpotential interaction and soft term with cp - violating phases, significant edms can arise from the two - loop effects of $ w $ bosons and tops. we compare the bounds arising from edms to those from other probes of new physics including colliders, $ b \ to s \ gamma $, and dark matter searches. importantly, improvements in reach not only constrain higher masses, but require the phases to be significantly smaller in the natural parameter space at low mass. the required smallness of phases sharpens the cp problem of natural susy model building. | arxiv:1612.08090 |
mandating public availability of computer code underlying computational simulation modeling research ends up doing a disservice to the cause of model verification when inconsistencies between the specifications in the publication text and specifications in the computer code go unchallenged. conversely, a model is verified when an independent researcher undertakes the set of mental processing tasks necessary to convert natural language specifications in a publication text into computer code instructions that produce numerical or graphical outputs identical to the outputs found in the original publication. the effort towards obtaining convergence with the numerical or graphical outputs directs intensive consideration of the publication text. the original computer code has little role to play in determining the verification status - verified / failed verification. an insight is obtained that skillful deployment of human intelligence is feasible when effort - directing feedback processes are in place to appropriately go around the human frailty of giving up in the absence of actionable feedback. this principle can be put to use to develop better organizational configurations in business, government and society. | arxiv:2105.05170 |
the alpdmn quasicrystal approximants xi, xi ', and xi ' _ n of the 1. 6 nm decagonal phase and r, t, and t _ n of the 1. 2 nm decagonal phase can be viewed as arrangements of cluster columns on two - dimensional tilings. we substitute the tiles by penrose rhombs and show, that alternative tilings can be constructed by a simple cut and projection formalism in three dimensional hyperspace. it follows that in the approximants there is a phasonic degree of freedom, whose excitation results in the reshuffling of the clusters. we apply the tiling model for metadislocations, which are special textures of partial dislocations. | arxiv:0704.1440 |
the spatial fluctuations of deformation are studied in creep in the andrade ' s power - law and the logarithmic phases, using paper samples. measurements by the digital image correlation technique show that the relative strength of the strain rate fluctuations increases with time, in both creep regimes. in the andrade creep phase characterized by a power law decay of the strain rate $ \ epsilon _ t \ sim t ^ { - \ theta } $, with $ \ theta \ approx 0. 7 $, the fluctuations obey $ \ delta \ epsilon _ t \ sim t ^ { - \ gamma } $, with $ \ gamma \ approx 0. 5 $. the local deformation follows a data collapse appropriate for an absorbing state / depinning transition. similar behavior is found in a crystal plasticity model, with a jamming or yielding phase transition. | arxiv:1007.4688 |
in this paper we have studied downlink packet scheduling algorithms proposed for lte cellular networks. the study emphasize on three most promising scheduling algorithms such as : fls, exp rule and log rule. the performance of these three algorithms is conducted over video traffic in a vehicular environment using lte - sim simulator. the simulation was setup with varying number of users from 10 - 60 in fixed bounded regions of 1 km radius. the main goal this study is to provide results that will help in the design process of packet scheduler for lte cellular networks, aiming to get better overall performance users. simulation results show that, the fls scheme outperforms in terms of average system throughput, average packet delay, plr ; and with a satisfactory level of fairness index. | arxiv:1307.3144 |
non - markovian quantum effects are typically observed in systems interacting with structured reservoirs. discrete - time quantum walks are prime example of such systems in which, quantum memory arises due to the controlled interaction between the coin and position degrees of freedom. here we show that the information backflow that quantifies memory effects can be enhanced when the particle is subjected to uncorrelated static or dynamic disorder. the presence of disorder in the system leads to localization effects in 1 - dimensional quantum walks. we shown that it is possible to infer about the nature of localization in position space by monitoring the information backflow in the reduced system. further, we study other useful properties of quantum walk such as entanglement, interference and its connection to quantum non - markovianity. | arxiv:1802.05478 |
we prove a strong version of the max - flow min - cut theorem for countable networks, namely that in every such network there exist a flow and a cut that are " orthogonal " to each other, in the sense that the flow saturates the cut and is zero on the reverse cut. if the network does not contain infinite trails then this flow can be chosen to be mundane, i. e. to be a sum of flows along finite paths. we show that in the presence of infinite trails there may be no orthogonal pair of a cut and a mundane flow. we finally show that for locally finite networks there is an orthogonal pair of a cut and a flow that satisfies kirchhoff ' s first law also for ends. | arxiv:0911.4003 |
we study the deeply - virtual compton scattering ( dvcs ) process $ e ^ - n \ to e ^ - \ gamma \ pi n $ involving the transition between a nucleon and a nucleon resonance in the $ \ pi n $ system, within the framework of generalized parton distributions ( gpds ). for the four lowest - lying nucleon resonances, $ \ delta ( 1232 ) $, $ p _ { 11 } ( 1440 ) $, $ d _ { 13 } ( 1520 ) $, and $ s _ { 11 } ( 1535 ) $, we express the dvcs amplitude in the bjorken limit in terms of corresponding nucleon - to - resonance gpds. building upon the knowledge of the well studied electromagnetic nucleon - to - resonance transition form factors, which map the quark charge densities in transverse position space, the corresponding gpds will open the prospect to also access the longitudinal momentum distributions of quarks in the transition. we provide estimates for cross sections and beam - spin asymmetries in the first and second $ \ pi n $ resonance regions in the kinematics of forthcoming clas12 data from jefferson lab. | arxiv:2303.00119 |
we show how an induced invariance of the massless particle action can be used to construct an extension of the heisenberg canonical commutation relations in a non - commutative space - time. | arxiv:hep-th/0508087 |
a technique using a systolic array structure is proposed for solving the common approximate substring ( cas ) problem. this approach extends the technique introduced in earlier work from the computation of the edit - distance between two strings to the more encompassing cas problem. a comparison to existing work is given, and the technique presented is validated and analyzed based on simulations. | arxiv:1006.1104 |
improper disposal of e - waste poses global environmental and health risks, raising serious concerns. the accurate classification of e - waste images is critical for efficient management and recycling. in this paper, we have presented a comprehensive dataset comprised of eight different classes of images of electronic devices named the e - waste vision dataset. we have also presented ewastenet, a novel two - stream approach for precise e - waste image classification based on a data - efficient image transformer ( deit ). the first stream of ewastenet passes through a sobel operator that detects the edges while the second stream is directed through an atrous spatial pyramid pooling and attention block where multi - scale contextual information is captured. we train both of the streams simultaneously and their features are merged at the decision level. the deit is used as the backbone of both streams. extensive analysis of the e - waste dataset indicates the usefulness of our method, providing 96 % accuracy in e - waste classification. the proposed approach demonstrates significant usefulness in addressing the global concern of e - waste management. it facilitates efficient waste management and recycling by accurately classifying e - waste images, reducing health and safety hazards associated with improper disposal. | arxiv:2311.12823 |
in this paper, we investigate the reconfigurable intelligent surface ( ris ) - aided terahertz ( thz ) communication system with the sparse radio frequency chains antenna structure at the base station ( bs ). to overcome the beam split of the bs, different from the conventional single - layer true - time - delay ( ttd ) scheme, we propose a double - layer ttd scheme that can effectively reduce the number of large - range delay devices, which involve additional insertion loss and amplification circuitry. next, we analyze the system performance under the proposed double - layer ttd scheme. to relieve the beam split of the ris, we consider multiple distributed riss to replace an ultra - large size ris. based on this, we formulate an achievable rate maximization problem for the distributed riss - aided thz communications via jointly optimizing the hybrid analog / digital beamforming, time delays of the double - layer ttd network and reflection coefficients of riss. considering the practical hardware limitation, the finite - resolution phase shift, time delay and reflection phase are constrained. to solve the formulated problem, we first design an analog beamforming scheme including optimizing phase shift and time delay based on the riss ' locations. then, an alternatively optimization algorithm is proposed to obtain the digital beamforming and reflection coefficients based on the minimum mean square error and coordinate update techniques. finally, simulation results show the effectiveness of the proposed scheme. | arxiv:2310.13917 |
we study a scheme for electrical detection, using electron spin resonance, of coherent vibrations in a molecular single electron level trapped near a conduction channel. both equilibrium spin - currents and non - equilibrium spin - and charge currents are investigated. inelastic side - band anti - resonances corresponding to the vibrational modes appear in the electron spin resonance spectrum. | arxiv:0805.2919 |
we propose a novel generative model for multivariate discrete - time time series data. drawing inspiration from the construction of neural spline flows, our algorithm incorporates linear transformations and the signature transform as a seamless substitution for traditional neural networks. this approach enables us to achieve not only the universality property inherent in neural networks but also introduces convexity in the model ' s parameters. | arxiv:2307.09767 |
neutral - atomic and molecular outflows are a common occurrence in galaxies, near and far. they operate over the full extent of their galaxy hosts, from the innermost regions of galactic nuclei to the outermost reaches of galaxy halos. they carry a substantial amount of material that would otherwise have been used to form new stars. these cool outflows may have a profound impact on the evolution of their host galaxies and environments. this article provides an overview of the basic physics of cool outflows, a comprehensive assessment of the observational techniques and diagnostic tools used to characterize them, a detailed description of the best - studied cases, and a more general discussion of the statistical properties of these outflows in the local and distant universe. the remaining outstanding issues that have not yet been resolved are summarized at the end of the review to inspire new research directions. | arxiv:2002.07765 |
march β firefly aerospace successfully lands the blue ghost mission 1 on the moon as part of nasa ' s commercial lunar payload services program, delivering payloads to mare crisium with instruments to study lunar regoliths and the interactions between solar wind and earth ' s magnetic field. 4 march β de - extinction company colossal biosciences announces the creation of a " woolly mouse " with eight modified genes, expressing mammoth - like traits relevant to cold adaptation and providing a platform for validation of genome engineering targets. 5 march β italian researchers report turning light into a supersolid for the first time. 6 march β a study in science finds that butterfly populations in the u. s. declined by 22 % between 2000 and 2020, with 13 times as many species decreasing as increasing, raising concerns about future biodiversity loss. 10 march β a study in the journal pnas finds that microplastic pollution reduces photosynthesis in plants and algae by up to 12 %, leading to estimated annual food losses of 110 β 361 million tonnes of crops and up to 24 million tonnes of seafood. without action to reduce plastic waste, this could lead to another 400 million people at risk of starvation within two decades. 11 march the discovery of 128 new moons of saturn is reported, by astronomers using the canada β france β hawaii telescope, bringing the gas giant ' s total number of confirmed satellites to 274. three new rocky exoplanets, all smaller than earth in size, are detected around barnard ' s star, the closest solitary star to our own sun at just 5. 96 light - years away. barnard b, a candidate world that observations had hinted at previously, is also confirmed, bringing the total number of known planets around the star to four. 13 march β the first image of two pink1 proteins attached to the membrane of a mitochondrion is obtained, via cryo - electron microscopy, a potential breakthrough in developing treatments for parkinson ' s disease. 20 march β oxygen is discovered in jades - gs - z14 - 0, the most distant known galaxy, located 13. 4 billion light - years from earth. 26 march aurorae are confirmed on neptune for the first time, seen by combining visible light images from the hubble space telescope with near - infrared images from the james webb space telescope. a study in the lancet finds that cuts to foreign aid proposed by major donor countries, such as the us and uk, could undo decades of progress made to end hiv / aids as a public health threat, with potentially 10. 8m | https://en.wikipedia.org/wiki/2025_in_science |
the exploration and understanding of executable and linkable format ( elf ) objects underpin various critical activities in computer systems, from debugging to reverse engineering. traditional unix tooling like readelf, nm, and objdump have served the community reliably over the years. however, as the complexity and scale of software projects has grown, there arises a need for more intuitive, flexible, and powerful methods to investigate elf objects. in this paper, we introduce sqlelf, an innovative tool that empowers users to probe elf objects through the expressive power of sql. by modeling elf objects as relational databases, sqlelf offers the following advantages over conventional methods. our evaluations demonstrate that sqlelf not only provides more nuanced and comprehensive insights into elf objects but also significantly reduces the effort and time traditionally required for elf exploration tasks | arxiv:2405.03883 |
we describe the dynamics of a stream of equally spaced macroscopic particles in orbit around a central body ( e. g. a planet or star ). a co - orbital configuration of small bodies may be subject to gravitational instability, which takes the system to a spreading, disordered and collisional state. we detail the linear instability ' s mathematical and physical features using the shearing sheet model and subsequently track its nonlinear evolution with local n - body simulations. this model provides a convenient tool with which to understand the gravitational and collisional dynamics of narrow belts, such as saturn ' s f - ring and the streams of material wrenched from tidally disrupted bodies. in particular, we study the tendency of these systems to form long - lived particle aggregates. finally, we uncover an unexpected connection between the linear dynamics of the gravitational instability and the magnetorotational instability. | arxiv:1203.4192 |
a random vector whose norm and overlap ( inner product with an independent copy ) concentrates is shown to have random low - dimensional projections that are approximately random gaussians. conversely, asymptotically random gaussian projections imply these hypotheses. this extends and unites several existing results in geometric functional analysis and spin glasses. applications include a large - system characterization of the joint law of cavity fields in the sherrington - kirkpatrick model. | arxiv:2312.01248 |
antiferromagnetic ( afm ) insulators exhibit many desirable features for spintronic applications such as fast dynamics in the thz range and robustness to fluctuating external fields. however, large damping typically associated with thz magnons presents a serious challenge for thz magnonic applications. here, we report long - lived short - wavelength zone boundary magnons in the honeycomb afm insulator cotio3, recently found to host topological magnons. we find that its zone - boundary thz magnons exhibit longer lifetimes than its zone - center magnons. this unusual momentum - dependent long magnon lifetime originates from several factors including the antiferromagnetic order, exchange anisotropy, a finite magnon gap, and magnon band dispersion. our work suggests that magnon - magnon interaction may not be detrimental to magnon lifetimes and should be included in future searches for topological magnons. | arxiv:2504.14742 |
for an additive group $ \ gamma $ the sequence $ s = ( g _ 1, \ ldots, g _ t ) $ of elements of $ \ gamma $ is a zero - sum sequence if $ g _ 1 + \ cdots + g _ t = 0 _ \ gamma $. the cross number of $ s $ is defined to be the sum $ \ sum _ { i = 1 } ^ k 1 / | g _ i | $, where $ | g _ i | $ denotes the order of $ g _ i $ in $ \ gamma $. call $ s $ good if it contains a zero - sum subsequence with cross number at most 1. in 1993, geroldinger proved that if $ \ gamma $ is abelian then every length $ | \ gamma | $ sequence of its elements is good, generalizing a 1989 result of lemke and kleitman that had proved an earlier conjecture of erd \ h { o } s and lemke. in 1989 chung re - proved the lemke and kleitman result by applying a theorem of graph pebbling, and in 2005, elledge and hurlbert used graph pebbling to re - prove and generalize geroldinger ' s result. here we use probabilistic theorems from graph pebbling to derive a threshold version of geroldinger ' s theorem for abelian groups of a certain form. specifically, we prove that if $ p _ 1, \ ldots, p _ d $ are ( not necessarily distinct ) primes and $ \ gamma _ k $ has the form $ \ prod _ { i = 1 } ^ d { \ mathbb z } _ { p _ i ^ k } $ then there is a function $ \ tau = \ tau ( k ) $ ( which we specify in theorem 4 ) with the following property : if $ t - \ tau \ rightarrow \ infty $ as $ k \ rightarrow \ infty $ then the probability that $ s $ is good in $ \ gamma _ k $ tends to 1. | arxiv:2309.03455 |
we study a class of two - point functions in a conformal field theory near a wedge. this is a set - up with two boundaries intersecting at an angle $ \ theta $. we compute it as a solution to the dyson - schwinger equation of motion for a quartic interaction in the $ d = 4 - \ epsilon $ bulk and in the $ d = 3 - \ epsilon $ boundary, up to order $ \ mathcal { o } ( \ epsilon ) $. we have extracted the anomalous dimensions from such correlators and we have complemented them with feynman diagrams computations. | arxiv:2206.06326 |
while convolutional neural networks ( cnns ) have become the de facto standard for most image processing and computer vision applications, their deployment on edge devices remains challenging. tensor decomposition methods provide a means of compressing cnns to meet the wide range of device constraints by imposing certain factorization structures on their convolution tensors. however, being limited to the small set of factorization structures presented by state - of - the - art decomposition approaches can lead to sub - optimal performance. we propose sekron, a novel tensor decomposition method that offers a wide variety of factorization structures, using sequences of kronecker products. by recursively finding approximating kronecker factors, we arrive at optimal decompositions for each of the factorization structures. we show that sekron is a flexible decomposition that generalizes widely used methods, such as tensor - train ( tt ), tensor - ring ( tr ), canonical polyadic ( cp ) and tucker decompositions. crucially, we derive an efficient convolution projection algorithm shared by all sekron structures, leading to seamless compression of cnn models. we validate sekron for model compression on both high - level and low - level computer vision tasks and find that it outperforms state - of - the - art decomposition methods. | arxiv:2210.06299 |
we study the gravitational lensing influence of a massive object in a dark matter halo, using a simple model of a point mass embedded in a spherical navarro - - frenk - - white halo. building on the analysis of critical curves and caustics presented in the first part of this work, we proceed to explore the geometry of images formed by the lens. first, we analyze several lensing quantities including shear, phase, and their weak - lensing approximations, illustrating the results with image - plane maps. we derive formulae and present a geometric interpretation for the shear and phase of a combination of two axially symmetric mass distributions. in the case of our lens model, we describe the occurrence of zero - shear points and specify the conditions under which they become umbilic points. second, we use the eigenvalue decomposition of the inverse of the lens - equation jacobian matrix to compute the magnification and flattening of lensed images. based on this, we introduce the convergence - - shear diagram, a novel and compact way of visualizing the properties of images formed by a particular gravitational lens. we inspect relative deviations of the analyzed lensing quantities in order to evaluate the perturbing effect of the point mass and the applicability of the weak - lensing approximation. we explore the dependence of the results on the point - mass parameters by studying grids of plots for different combinations of its position and mass. we provide analytical explanations for important patterns arising in these plots and discuss the implications for the lensing influence of isolated compact bodies in dark matter halos. | arxiv:2109.02495 |
dynamic time warping distance ( dtw ) is a widely used distance measure between time series $ x, y \ in \ sigma ^ n $. it was shown by abboud, backurs, and williams that in the \ emph { binary case }, where $ | \ sigma | = 2 $, dtw can be computed in time $ o ( n ^ { 1. 87 } ) $. we improve this running time $ o ( n ) $. moreover, if $ x $ and $ y $ are run - length encoded, then there is an algorithm running in time $ \ tilde { o } ( k + \ ell ) $, where $ k $ and $ \ ell $ are the number of runs in $ x $ and $ y $, respectively. this improves on the previous best bound of $ o ( k \ ell ) $ due to dupont and marteau. | arxiv:2101.01108 |
this work introduces pyramidal convolution ( pyconv ), which is capable of processing the input at multiple filter scales. pyconv contains a pyramid of kernels, where each level involves different types of filters with varying size and depth, which are able to capture different levels of details in the scene. on top of these improved recognition capabilities, pyconv is also efficient and, with our formulation, it does not increase the computational cost and parameters compared to standard convolution. moreover, it is very flexible and extensible, providing a large space of potential network architectures for different applications. pyconv has the potential to impact nearly every computer vision task and, in this work, we present different architectures based on pyconv for four main tasks on visual recognition : image classification, video action classification / recognition, object detection and semantic image segmentation / parsing. our approach shows significant improvements over all these core tasks in comparison with the baselines. for instance, on image recognition, our 50 - layers network outperforms in terms of recognition performance on imagenet dataset its counterpart baseline resnet with 152 layers, while having 2. 39 times less parameters, 2. 52 times lower computational complexity and more than 3 times less layers. on image segmentation, our novel framework sets a new state - of - the - art on the challenging ade20k benchmark for scene parsing. code is available at : https : / / github. com / iduta / pyconv | arxiv:2006.11538 |
since 2016 october, the active galaxy pks 2247 - 131 has undergone a gamma - ray outburst, which we studied using data obtained with the fermi gamma - ray space telescope. the emission arises from a relativistic jet in pks 2247 - 131, as an optical spectrum only shows a few weak absorption lines, typical of the bl lacertae sub - class of the blazar class of active galactic nuclei. here we report a ~ 34. 5 day quasi - periodic oscillation ( qpo ) in the emission after the initial flux peak of the outburst. compared to one - year time - scale qpos, previously identified in blazars in fermi energies, pks 2247 - 131 exhibits the first clear case of a relatively short, month - like oscillation. we show that this qpo can be explained in terms of a helical structure in the jet, where the viewing angle to the dominant emission region in the jet undergoes periodic changes. the time scale of the qpo suggests the presence of binary supermassive black holes in pks 2247 - 131. | arxiv:1811.02738 |
for a class of divergence type quasi - linear degenerate parabolic equations with a radon measure on the right hand side we derive pointwise estimates for solutions via nonlinear wolff potentials. | arxiv:1004.3045 |
we study the thermodynamics of the recently - discovered non - extremal charged rotating black holes of gauged supergravities in five, seven and four dimensions, obtaining energies, angular momenta and charges that are consistent with the first law of thermodynamics. we obtain their supersymmetric limits by using these expressions together with an analysis of the ads superalgebras including r - charges. we give a general discussion of the global structure of such solutions, and apply it in the various cases. we obtain new regular supersymmetric black holes in seven and four dimensions, as well as reproducing known examples in five and four dimensions. we also obtain new supersymmetric non - singular topological solitons in five and seven dimensions. the rest of the supersymmetric solutions either have naked singularities or naked time machines. the latter can be rendered non - singular if the asymptotic time is periodic. this leads to a new type of quantum consistency condition, which we call a josephson quantisation condition. finally, we discuss some aspects of rotating black holes in godel universe backgrounds. | arxiv:hep-th/0504080 |
a procedure inspired by the tamm - dancoff method is applied to the chiral quark model which has been extended to include additional degrees of freedom : a pseudoscalar isoscalar field as well as a triplet of scalar isovector fields. the simpler, generic $ \ sigma $ - - model has been used before as a test for the tamm - dancoff inspired approximation ( tdia ). the extended chirial quark model is employed here to investigate possible novel effects of the additional degrees of freedom as well as to point out the necessesity to introduce a su ( 3 ) flavour. model predictions for the axial - vector coupling constant and for the nucleon magnetic moment obtained in tdia are compared with experimental values. | arxiv:hep-ph/0012117 |
we study the resonant inelastic x - ray scattering ( rixs ) features of vector chiral ordered kagome antiferromagnets. utilizing a group theoretical formalism that respects lattice site symmetry, we calculated the $ l $ - edge magnon contribution for the vesignieite compound bacu $ _ { 3 } $ v $ _ { 2 } $ o $ _ { 8 } $ ( oh ) $ _ { 2 } $. we show that polarization dependence of the $ l $ - edge rixs spectrum can be used to track magnon branches. we predict a non - zero $ l $ - edge signal in the non - cross $ \ pi - \ pi $ polarization channel. at the $ k $ - edge, we derived the two - site effective rixs and raman scattering operator for two - magnon excitation in vesignieite using the shastry - shraiman formalism. our derivation considers spin - orbit coupling effects in virtual hopping processes. we find vector chiral correlation ( four - spin ) contribution that is proportional to the rixs spectrum. our scattering operator formalism can be applied to a host of non - collinear non - coplanar magnetic materials at both the $ l $ and $ k $ - edge. we demonstrate that vector chiral correlations can be accessed by rixs experiments. | arxiv:2004.02871 |
the method for functional reduction of feynman integrals, proposed by the author, is used to calculate one - loop integrals corresponding to diagrams with four external lines. the integrals that emerge from amplitudes for the scattering of light by light, the photon splitting in an external field and delbr \ " { u } ck scattering are considered. for master integrals in $ d $ - dimensions, new analytic results are presented. for $ d = 4 $, these integrals are given by compact expressions in terms of logarithms and dilogarithms. | arxiv:2211.15535 |
most of results of bestvina and mogilski [ \ textit { characterizing certain incomplete infinite - dimensional absolute retracts }, michigan math. j. \ textbf { 33 } ( 1986 ), 291 - - 313 ] on strong $ z $ - sets in anr ' s and absorbing sets is generalized to nonseparable case. it is shown that if an anr $ x $ is locally homotopy dense embeddable in infinite - dimensional hilbert manifolds and $ w ( u ) = w ( x ) $ ( where ` $ w $ ' is the topological weight ) for each open nonempty subset $ u $ of $ x $, then $ x $ itself is homotopy dense embeddable in a hilbert manifold. it is also demonstrated that whenever $ x $ is an ar, its weak product $ w ( x, * ) = \ { ( x _ n ) _ { n = 1 } ^ { \ infty } \ in x ^ { \ omega } : \ x _ n = * \ textup { for almost all } n \ } $ is homeomorphic to a pre - hilbert space $ e $ with $ e \ cong \ sigma e $. an intrinsic characterization of manifolds modelled on such pre - hilbert spaces is given. | arxiv:1107.1502 |
public transit disruption is becoming more common across different transit services, which can have a destructive influence on the resiliency and reliability of the transportation system. utilizing a recently collected data of transit users in the chicago metropolitan area, the current study aims to analyze how transit users respond to unplanned service disruption and disclose the factors that affect their behavior. | arxiv:2001.01718 |
we have embedded an artificial atom, a superconducting transmon qubit, in a 1d open space and investigated the scattering properties of an incident microwave coherent state. by studying the statistics of the reflected and transmitted fields, we demonstrate that the scattered states can be nonclassical. in particular, by measuring the second - order correlation function, $ g ^ { ( 2 ) } $, we show photon antibunching in the reflected field and superbunching in the transmitted field. we also compare the elastically and inelastically scattered fields using both phase - sensitive and phase - insensitive measurements. | arxiv:1201.2269 |
performance evaluation of the routing node in terms of latency is the characteristics of an efficient design of buffer in input module. it is intended to study and quantify the behavior of the single packet array design in relation to the multiple packet array design. the utilization efficiency of the packet buffer array improves when a common buffer is used instead of individual buffers in each input port. first poissons queuing model was prepared to manifest the differences in packet delays. the queuing model can be classified as ( m / m / 1 ), ( 32 / fifo ). arrival rate has been assumed to be poisson distributed with a mean arrival rate of 10 x 1000000. the service rate is assumed to be exponentially distributed with a mean service rate of 10. 05 x 1000000. it has been observed that latency in common buffer improved by 46 percent over its distributed buffer. a simulink model later simulated on matlab to calculate the improvement in packet delay. it has been observed that the delay improved by approximately 40 percent through the use of a common buffer. a verilog rtl for both common and shared buffer has been prepared and later synthesized using design compiler of synopsys. in distributed buffer, arrival of data packet could be delayed by 2 or 4 clock cycles which lead to latency improvement either by 17 percent or 34 percent in a common buffer | arxiv:1302.4172 |
the demand for efficient large language model ( llm ) inference has propelled the development of dedicated accelerators. as accelerators are vulnerable to hardware faults due to aging, variation, etc, existing accelerator designs often reserve a large voltage margin or leverage algorithm - based fault tolerance ( abft ) techniques to ensure llm inference correctness. however, previous methods often overlook the inherent fault tolerance of llms, leading to high computation and energy overhead. to enable reliable yet efficient llm inference, in this paper, we propose a novel algorithm / circuit co - design framework, dubbed realm. for the first time, we systematically characterize the fault tolerance of llms by performing a large - scale error injection study of representative llms and natural language understanding tasks. then, we propose a statistical abft algorithm that fully leverages the error robustness to minimize error recovery as much as possible. we also customize the error detection circuits to enable a low - cost online collection of error statistics. extensive experiments show that with only 1. 42 % circuit area and 1. 79 % power overhead, our realm can reduce perplexity degradation from 18. 54 to 0. 29. compared to existing methods, realm consistently reduces recovery costs across different operating voltages and improves energy efficiency by up to 35. 83 % without compromising llm performance. our error injection code is available at https : / / github. com / pku - sec - lab / realm _ dac25 / | arxiv:2503.24053 |
results from a phenomenological analysis of dijet and w hard diffractive hadroproduction at fermilab tevatron energies are reported. the theoretical framework employed here is a modified version of the ingelman - schlein approach which includes dglap - evolved structure functions. different from what has been achieved by the desy ep hera reactions, a reasonable overall description of such diffractive hadron processes is obtained only when a complex, quark - rich pomeron structure function is employed in the calculation. | arxiv:hep-ph/0212349 |
computing the convolution $ a \ star b $ of two length - $ n $ vectors $ a, b $ is an ubiquitous computational primitive. applications range from string problems to knapsack - type problems, and from 3sum to all - pairs shortest paths. these applications often come in the form of nonnegative convolution, where the entries of $ a, b $ are nonnegative integers. the classical algorithm to compute $ a \ star b $ uses the fast fourier transform and runs in time $ o ( n \ log n ) $. however, often $ a $ and $ b $ satisfy sparsity conditions, and hence one could hope for significant improvements. the ideal goal is an $ o ( k \ log k ) $ - time algorithm, where $ k $ is the number of non - zero elements in the output, i. e., the size of the support of $ a \ star b $. this problem is referred to as sparse nonnegative convolution, and has received considerable attention in the literature ; the fastest algorithms to date run in time $ o ( k \ log ^ 2 n ) $. the main result of this paper is the first $ o ( k \ log k ) $ - time algorithm for sparse nonnegative convolution. our algorithm is randomized and assumes that the length $ n $ and the largest entry of $ a $ and $ b $ are subexponential in $ k $. surprisingly, we can phrase our algorithm as a reduction from the sparse case to the dense case of nonnegative convolution, showing that, under some mild assumptions, sparse nonnegative convolution is equivalent to dense nonnegative convolution for constant - error randomized algorithms. specifically, if $ d ( n ) $ is the time to convolve two nonnegative length - $ n $ vectors with success probability $ 2 / 3 $, and $ s ( k ) $ is the time to convolve two nonnegative vectors with output size $ k $ with success probability $ 2 / 3 $, then $ s ( k ) = o ( d ( k ) + k ( \ log \ log k ) ^ 2 ) $. our approach uses a variety of new techniques in combination with some old machinery from linear sketching and structured linear algebra, as well as new insights on linear hashing, the most classical hash function. | arxiv:2105.05984 |
in the pac - bayesian literature, the c - bound refers to an insightful relation between the risk of a majority vote classifier ( under the zero - one loss ) and the first two moments of its margin ( i. e., the expected margin and the voters ' diversity ). until now, learning algorithms developed in this framework minimize the empirical version of the c - bound, instead of explicit pac - bayesian generalization bounds. in this paper, by directly optimizing pac - bayesian guarantees on the c - bound, we derive self - bounding majority vote learning algorithms. moreover, our algorithms based on gradient descent are scalable and lead to accurate predictors paired with non - vacuous guarantees. | arxiv:2104.13626 |
the sensitivity of magnetic and electric field sensors based on nitrogen - vacancy ( nv ) center in diamond strongly depends on the available concentration of nv and their coherence properties. achieving high coherence times simultaneously with high concentration is a challenging experimental task. here, we demonstrate that by using a high - pressure, high - temperature growing technique, one can achieve nearly maximally possible effective coherence t2 * times, limited only by carbon nuclear spins at low nitrogen concentrations or nitrogen electron spin at high nitrogen concentrations. hahn - echo t2 coherence times were also investigated and found to demonstrate reasonable values. thus, the high - pressure, high - temperature technique is a strong contender to the popular chemical vapor deposition method in the development of high - sensitivity, diamond - based sensors. | arxiv:1806.09816 |
the elemental abundances of planet host stars can shed light on the conditions of planet forming environments. we test if individual abundances of 130 known / candidate planet hosts in apogee are statistically different from those of a reference doppelganger sample. the reference set comprises objects selected with the same teff, logg, [ fe / h ], and [ mg / h ] as each kepler object of interest ( koi ). we predict twelve individual abundances ( x = c, n, o, na, al, si, ca, ti, v, cr, mn, ni ) for the kois and their doppelgangers using a local linear model of these four parameters, training on aspcap abundance measurements for a sample of field stars with high fidelity ( snr > 200 ) apogee observations. we compare element prediction residuals ( model - measurement ) for the two samples and find them to be indistinguishable, given a high quality sample selection. we report median intrinsic dispersions of ~ 0. 038 dex and ~ 0. 041 dex, for the koi and doppelganger samples, respectively, for these elements. we conclude that the individual abundances at fixed teff, logg, [ fe / h ], and [ mg / h ] are unremarkable for known planet hosts. our results establish an upper limit on the abundance precision required to uncover any chemical signatures of planet formation in planet host stars. | arxiv:2210.14187 |
this paper investigates a solution for enabling in - context capabilities of video diffusion transformers, with minimal tuning required for activation. specifically, we propose a simple pipeline to leverage in - context generation : ( $ \ textbf { i } $ ) concatenate videos along spacial or time dimension, ( $ \ textbf { ii } $ ) jointly caption multi - scene video clips from one source, and ( $ \ textbf { iii } $ ) apply task - specific fine - tuning using carefully curated small datasets. through a series of diverse controllable tasks, we demonstrate qualitatively that existing advanced text - to - video models can effectively perform in - context generation. notably, it allows for the creation of consistent multi - scene videos exceeding 30 seconds in duration, without additional computational overhead. importantly, this method requires no modifications to the original models, results in high - fidelity video outputs that better align with prompt specifications and maintain role consistency. our framework presents a valuable tool for the research community and offers critical insights for advancing product - level controllable video generation systems. the data, code, and model weights are publicly available at : https : / / github. com / feizc / video - in - context. | arxiv:2412.10783 |
we show that all countable subsets of any pseudocompact quasitopological group in the form of a korovin orbit are closed, discrete, and $ c ^ \ ast $ - embedded. consequently, any infinite pseudocompact korovin orbit is not homeomorphic to a topological group. moreover, infinite pseudocompact korovin orbits are not homeomorphic to any mal ' tsev space. | arxiv:2302.11251 |
the countdown game is one of the oldest tv show running in the world. it started broadcasting in 1972 on the french television and in 1982 on british channel 4, and it has been running since in both countries. the game, while extremely popular, never received any serious scientific attention, probably because it seems too simple at first sight. we present in this article an in - depth analysis of the numbers round of the countdown game. this includes a complexity analysis of the game, an analysis of existing algorithms, the presentation of a new algorithm that increases resolution speed by a factor of 20. it also includes some leads on how to turn the game into a more difficult one, both for a human player and for a computer, and even to transform it into a probably undecidable problem. | arxiv:1502.05450 |
we study the dynamical localization of discrete time evolution of topological split - step quantum random walk ( qrw ) on a single - site defect starting from a uniform distribution. using analytical and numerical calculations, we determine the high localization probability regions in the parameter space of the quantum walker. these regions contain two or more pairs of trapped states, forming near a lattice defect. by investigating the spectral properties of the discrete - time evolution operators, we show that these trapped states have large overlap with the initial uniformly distributed state, thus offering a simple interpretation of the localization effect. as this localization scheme could be interpreted as a variation of spatial quantum search algorithm, we compare the localization probability and time with other types of two - dimensional quantum walks that do not have topological phases and realize localization time scaling similar to grover ' s algorithm. finally we show that mechanism of localization we identified is robust against the influence of disorder. | arxiv:2406.18768 |
age progression / regression is a challenging task due to the complicated and non - linear transformation in human aging process. many researches have shown that both global and local facial features are essential for face representation, but previous gan based methods mainly focused on the global feature in age synthesis. to utilize both global and local facial information, we propose a global and local consistent age generative adversarial network ( glca - gan ). in our generator, a global network learns the whole facial structure and simulates the aging trend of the whole face, while three crucial facial patches are progressed or regressed by three local networks aiming at imitating subtle changes of crucial facial subregions. to preserve most of the details in age - attribute - irrelevant areas, our generator learns the residual face. moreover, we employ an identity preserving loss to better preserve the identity information, as well as age preserving loss to enhance the accuracy of age synthesis. a pixel loss is also adopted to preserve detailed facial information of the input face. our proposed method is evaluated on three face aging datasets, i. e., cacd dataset, morph dataset and fg - net dataset. experimental results show appealing performance of the proposed method by comparing with the state - of - the - art. | arxiv:1801.08390 |
just noticeable distortion ( jnd ), representing the threshold of distortion in an image that is minimally perceptible to the human visual system ( hvs ), is crucial for image compression algorithms to achieve a trade - off between transmission bit rate and image quality. however, traditional jnd prediction methods only rely on pixel - level or sub - band level features, lacking the ability to capture the impact of image content on jnd. to bridge this gap, we propose a semantic - guided jnd ( sg - jnd ) network to leverage semantic information for jnd prediction. in particular, sg - jnd consists of three essential modules : the image preprocessing module extracts semantic - level patches from images, the feature extraction module extracts multi - layer features by utilizing the cross - scale attention layers, and the jnd prediction module regresses the extracted features into the final jnd value. experimental results show that sg - jnd achieves the state - of - the - art performance on two publicly available jnd datasets, which demonstrates the effectiveness of sg - jnd and highlight the significance of incorporating semantic information in jnd assessment. | arxiv:2408.04273 |
we present a method to compute the photoionization spectra of atoms and molecules in linear response time - dependent density functional theory. the electronic orbital variations corresponding to ionized electrons are expanded on a basis set of delocalized functions obtained as the solution of the inhomogeneous helmholtz equation with gaussian basis set functions as right - hand side. the resulting scheme is able to reproduce photoionization spectra without any need for artificial regularization or localization. we demonstrate that it is able to produce accurate spectra for semilocal exchange - correlation functionals even using relatively small standard gaussian basis sets. | arxiv:2305.13736 |
the nature of the coupling leading to superconductivity in layered materials such as high - tc superconductors and graphite intercalation compounds ( gics ) is still unresolved. in both systems, interactions of electrons with either phonons or other electrons or both have been proposed to explain superconductivity. in the high - tc cuprates, the presence of a van hove singularity ( vhs ) in the density of states near the fermi level was long ago proposed to enhance the many - body couplings and therefore may play a role in superconductivity. such a singularity can cause an anisotropic variation in the coupling strength, which may partially explain the so - called nodal - antinodal dichotomy in the cuprates. here we show that the topology of the graphene band structure at dopings comparable to the gics is quite similar to that of the cuprates and that the quasiparticle dynamics in graphene have a similar dichotomy. namely, the electron - phonon coupling is highly anisotropic, diverging near a saddle point in the graphene electronic band structure. these results support the important role of the vhs in layered materials and the possible optimization of tc by tuning the vhs with respect to the fermi level. | arxiv:0705.3264 |
the tertiary instability is believed to be important for governing magnetised plasma turbulence under conditions of strong zonal flow generation, near marginal stability. in this work, we investigate its role for a collisionless strongly driven fluid model, self - consistently derived as a limit of gyrokinetics. it is found that a region of absolute stability above the linear threshold exists, beyond which significant nonlinear transport rapidly develops. while within this range a complex pattern of transient zonal evolution is observed before a stable profile is found, the dimits transition itself is found to coincide with a tertiary instability threshold so long as linear effects are included. through a simple and readily extendable procedure tracing its origin to st - onge 2017 ( arxiv : 1704. 05406 ) the stabilising effect of the typical zonal profile can be approximated and the accompanying reduced mode estimate is found to be in good agreement with nonlinear simulations. | arxiv:2012.09799 |
as machine learning models are considered for autonomous decisions with significant social impact, the need for understanding how these models work rises rapidly. explainable artificial intelligence ( xai ) aims to provide interpretations for predictions made by machine learning models, in order to make the model trustworthy and more transparent for the user. for example, selecting relevant input variables for the problem directly impacts the model ' s ability to learn and make accurate predictions, so obtaining information about input importance play a crucial role when training the model. one of the main xai techniques to obtain input variable importance is the sensitivity analysis based on partial derivatives. however, existing literature of this method provide no justification of the aggregation metrics used to retrieved information from the partial derivatives. in this paper, a theoretical framework is proposed to study sensitivities of ml models using metric techniques. from this metric interpretation, a complete family of new quantitative metrics called $ \ alpha $ - curves is extracted. these $ \ alpha $ - curves provide information with greater depth on the importance of the input variables for a machine learning model than existing xai methods in the literature. we demonstrate the effectiveness of the $ \ alpha $ - curves using synthetic and real datasets, comparing the results against other xai methods for variable importance and validating the analysis results with the ground truth or literature information. | arxiv:2305.02368 |
we have studied the energy dependence of several first scattering phases with multi - atomic object. as concrete examples representing the general trends endohedrals neon inside c60 and argon inside c60 are considered. it appeared that the presence of an inner atom, either ne or ar, qualitatively affects the scattering phases, in spite of the fact that the fullerene consists of 60 carbon atoms, while the atom staffed inside is only one. calculations are performed in the one - electron hartree - fock ( hf ) and random phase approximation with exchange ( rpae ) for the inner atom while the fullerenes shell is substituted by static potential without and with the polarization potential. it appeared that the total endohedral scattering phase is simply a sum of atomic, ne or ar, and fullerenes c60 phases, contrary to the intuitive assumption that the total phases on c60 and neon inside c60 or ar inside c60 has to be the same. | arxiv:1502.05566 |
we generalize the classical mean value theorem of differential calculus by allowing the use of a caputo - type fractional derivative instead of the commonly used first - order derivative. similarly, we generalize the classical mean value theorem for integrals by allowing the corresponding fractional integral, viz. \ the riemann - liouville operator, instead of a classical ( first - order ) integral. as an application of the former result we then prove a uniqueness theorem for initial value problems involving caputo - type fractional differential operators. this theorem generalizes the classical nagumo theorem for first - order differential equations. | arxiv:1709.01113 |
cs $ _ 2 $ lilabr $ _ 6 $ : ce $ ^ { 3 + } $ ( cllb ) is an elpasolite scintillator that offers excellent linearity and gamma - ray energy resolution and sensitivity to thermal neutrons with the ability to perform pulse - shape discrimination ( psd ) to distinguish gammas and neutrons. our investigation of cllb has indicated the presence of intrinsic radioactive alpha background that we have determined to be from actinium contamination of the lanthanum component. we measured the pulse shapes for gamma, thermal neutron, and alpha events and determined that psd can be performed to separate the alpha background with a moderate figure of merit of 0. 98. we also measured the electron - equivalent - energy of the alpha particles in cllb and simulated the intrinsic alpha background from $ ^ { 227 } $ ac to determine the quenching factor of the alphas. a linear quenching relationship $ l _ { \ alpha } = e _ { \ alpha } \ times q + l _ 0 $ was found at alpha particle energies above 5 mev, with a quenching factor $ q = 0. 71 $ mevee / mev and an offset $ l _ 0 = - 1. 19 $ mevee. | arxiv:1609.08490 |
sports betting markets are proven real - world laboratories to test theories of asset pricing anomalies and risky behaviour. using a high - frequency dataset provided directly by a major bookmaker, containing the odds and amounts staked throughout german bundesliga football matches, we test for evidence of momentum in the betting and pricing behaviour after equalising goals. we find that bettors see value in teams that have the apparent momentum, staking about 40 % more on them than teams that just conceded an equaliser. still, there is no evidence that such perceived momentum matters on average for match outcomes or is associated with the bookmaker offering favourable odds. we also confirm that betting on the apparent momentum would lead to substantial losses for bettors. | arxiv:2211.06052 |
recirculating energy recovery linacs are a promising technology for delivering high power particle beams ( $ \ sim $ gw ) while only requiring low power ( $ \ sim $ kw ) rf sources. this is achieved by decelerating the used bunches and using the energy they deposit in the accelerating structures to accelerate new bunches. we present studies of the impact of the bunch packet filling pattern on the performance of the accelerating rf system. we perform rf beam loading simulations under various noise levels and beam loading phases with different injection schemes. we also present a mathematical description of the rf system during the beam loading, which can identify optimal beam filling patterns under different conditions. the results of these studies have major implications for design constraints for future energy recovery linacs, by providing a quantitative metric for different machine designs and topologies. | arxiv:2001.04156 |
we for the first time report the truncated diffraction with a triangular aperture of the su ( 2 ) geometric modes and propose a method to detect the complicated orbital angular momentum ( oam ) of an su ( 2 ) wave - packet, to the best of our knowledge. as a special vortex beam, a nonplanar su ( 2 ) mode carrying special intensity and oam distributions brings exotic patterns in truncated diffraction lattice. a meshy structure is unveiled therein by adjusting the illuminated aperture in vicinity of the partial oam regions, which can be elaborately used to evaluate the partial topological charge and oam of an su ( 2 ) wave - packet by counting the dark holes in the mesh. moreover, through controlling the size and position of the aperture at the center region, the truncated triangular lattice can be close to the classical spot - array lattice for measuring the center oam. these effects being fully validated by theoretical simulations greatly extend the versatility of topological structures detection of special beams. | arxiv:1808.10318 |
we study dynamics of rolling tachyon and abelian gauge field on unstable d - branes, of which effective action is given by born - infeld type nonlocal action. possible cosmological evolutions are also discussed. in the einstein frame of string cosmology, every expanding flat universe is proven to be decelerating. | arxiv:hep-th/0301142 |
traditional graphics processing units ( gpus ) suffer from the low memory capacity and demand for high memory bandwidth. to address these challenges, we propose ohm - gpu, a new optical network based heterogeneous memory design for gpus. specifically, ohm - gpu can expand the memory capacity by combing a set of high - density 3d xpoint and dram modules as heterogeneous memory. to prevent memory channels from throttling throughput of gpu memory system, ohm - gpu replaces the electrical lanes in the traditional memory channel with a high - performance optical network. however, the hybrid memory can introduce frequent data migrations between dram and 3d xpoint, which can unfortunately occupy the memory channel and increase the optical network traffic. to prevent the intensive data migrations from blocking normal memory services, ohm - gpu revises the existing memory controller and designs a new optical network infrastructure, which enables the memory channel to serve the data migrations and memory requests, in parallel. our evaluation results reveal that ohm - gpu can improve the performance by 181 % and 27 %, compared to a dram - based gpu memory system and the baseline optical network based heterogeneous memory system, respectively. | arxiv:2109.05430 |
scattering of ortho positronium ( ps ) by cesium and rubidium atoms has been investigated employing a three - ps - state coupled - channel model with ps ( 1s, 2s, 2p ) states using a time - reversal - symmetric regularized electron - exchange model potential. we find a narrow s - wave singlet resonance at 5. 057 ev of width 0. 003 ev in the ps - rb system and at 5. 067 ev of width 0. 003 ev in the ps - cs system. singlet p - wave resonances in both systems are found at 5. 3 ev of width 0. 4 ev. singlet d - wave structures are found at 5. 4 ev in both systems. the pronounced p - and d - wave resonances in these systems lead to easily detectable local minima in the low - energy elastic cross sections. we also report results for elastic and ps - excitation cross sections for ps scattering by rb and cs. | arxiv:physics/0104037 |
we present a numerical study on non - fermi liquid behaviour of a three dimensional system. the hubbard model in a cubic lattice is simulated by the dynamical cluster approximation, in particular the quasi - particle weight is calculated at finite dopings for a range of temperatures. near the putative quantum critical point, we find evidence of a separatrix at a finite doping which separates the fermi liquid from non - fermi liquid as the doping increases. our results suggest that a marginal fermi liquid and possibly a quantum critical point should exist in the three dimensions interacting fermi system. | arxiv:2008.12324 |
the molecule solution of an equation related to the lattice boussinesq equation is derived with the help of determinantal identities. it is shown that this equation can for certain sequences be used as a numerical convergence acceleration algorithm. numerical examples with applications of this algorithm are presented. | arxiv:1105.3022 |
nuclear spin polarization induced by hyperfine interaction and the edelstein effect due to strong spin - orbit interaction is investigated by quantum transport in bi ( 111 ) thin film samples. the bi ( 111 ) films are deposited on mica by van der waals epitaxial growth. the bi ( 111 ) films show micrometer - sized triangular islands with 0. 39 nm step height, corresponding to the bi ( 111 ) bilayer height. at low temperatures a high current density is applied to generate a non - equilibrium carrier spin polarization by the edelstein effect at the bi ( 111 ) surface, which then induces dynamic nuclear polarization by hyperfine interaction. comparative quantum magnetotransport antilocalization measurements indicate a suppression of antilocalization by the in - plane overhauser field from the nuclear polarization and allow a quantification of the overhauser field. hence nuclear polarization was both achieved and quantified by a purely electronic transport - based approach. | arxiv:1906.05408 |
2022, nine satellites have been built with eight of them successfully operating in orbit. = = = european space agency ( esa ) = = = nasa collaborates with the european space agency on a wide range of scientific and exploration requirements. from participation with the space shuttle ( the spacelab missions ) to major roles on the artemis program ( the orion service module ), esa and nasa have supported the science and exploration missions of each agency. there are nasa payloads on esa spacecraft and esa payloads on nasa spacecraft. the agencies have developed joint missions in areas including heliophysics ( e. g. solar orbiter ) and astronomy ( hubble space telescope, james webb space telescope ). under the artemis gateway partnership, esa will contribute habitation and refueling modules, along with enhanced lunar communications, to the gateway. nasa and esa continue to advance cooperation in relation to earth science including climate change with agreements to cooperate on various missions including the sentinel - 6 series of spacecraft = = = japan aerospace exploration agency ( jaxa ) = = = nasa and the japan aerospace exploration agency ( jaxa ) cooperate on a range of space projects. jaxa is a direct participant in the artemis program, including the lunar gateway effort. jaxa ' s planned contributions to gateway include i - hab ' s environmental control and life support system, batteries, thermal control, and imagery components, which will be integrated into the module by the european space agency ( esa ) prior to launch. these capabilities are critical for sustained gateway operations during crewed and uncrewed time periods. jaxa and nasa have collaborated on numerous satellite programs, especially in areas of earth science. nasa has contributed to jaxa satellites and vice versa. japanese instruments are flying on nasa ' s terra and aqua satellites, and nasa sensors have flown on previous japanese earth - observation missions. the nasa - jaxa global precipitation measurement mission was launched in 2014 and includes both nasa - and jaxa - supplied sensors on a nasa satellite launched on a jaxa rocket. the mission provides the frequent, accurate measurements of rainfall over the entire globe for use by scientists and weather forecasters. = = = roscosmos = = = nasa and roscosmos have cooperated on the development and operation of the international space station since september 1993. the agencies have used launch systems from both countries to deliver station elements to orbit. astronauts and cosmonauts jointly maintain various elements of the station. both countries provide access to the station via launch systems noting russia ' s unique role as the sole provider of delivery of crew and | https://en.wikipedia.org/wiki/NASA |
we study creation of bi - and multipartite continuous variable entanglement in structures of coupled quantum harmonic oscillators. by adjusting the interaction strengths between nearest neighbors we show how to maximize the entanglement production between the arms in a y - shaped structure where an initial single mode squeezed state is created in the first oscillator of the input arm. we also consider the action of the same structure as an approximate quantum cloner. for a specific time in the system dynamics the last oscillators in the output arms can be considered as imperfect copies of the initial state. by increasing the number of arms in the structure, multipartite entanglement is obtained, as well as 1 to m cloning. finally, we are considering configurations that implement the symmetric splitting of an initial entangled state. all calculations are carried out within the framework of the rotating wave approximation in quantum optics, and our predictions could be tested with current available experimental techniques. | arxiv:quant-ph/0510105 |
we study $ d \ to \ pi \ pi $ decays with final state interactions considered in one - particle - exchange method. a clear physical picture for final state interactions based on quark and hadronic level diagrams is presented. a strong phase is introduced for hadronic effective couplings, which is crucial for explaining the experimental data of $ d ^ + \ to \ pi ^ + \ pi ^ 0 $, $ d ^ 0 \ to \ pi ^ + \ pi ^ - $, and $ d ^ 0 \ to \ pi ^ 0 \ pi ^ 0 $. rescattering effects between different $ d $ decay channels are usually large. they are important for obtaining correct branching ratios for $ d \ to \ pi \ pi $ decays in theoretical calculation. | arxiv:hep-ph/0201168 |
in social choice there often arises a conflict between the majority principle ( the search for a candidate that is as good as possible for as many voters as possible ), and the protection of minority rights ( choosing a candidate that is not overly bad for particular individuals or groups ). in a context where the latter is our main concern, veto - based rules - - giving individuals or groups the ability to strike off certain candidates from the list - - are a natural and effective way of ensuring that no minority is left with an outcome they find untenable. however, such rules often fail to be anonymous, or impose specific restrictions on the number of voters and candidates. these issues can be addressed by considering the proportional veto core - - the solution to a cooperative game where every coalition is given the power to veto a number of candidates proportional to its size. however, the na \ " ive algorithm for the veto core is exponential, and the only known rule for selecting from the core, with an arbitrary number of voters, fails anonymity. in this paper we present a polynomial time algorithm for computing the core, study its expected size, and present an anonymous rule for selecting a candidate from it. we study the properties of core - consistent voting rules. finally, we show that a pessimist can manipulate the core in polynomial time, while an optimist cannot manipulate it at all. | arxiv:2003.09153 |
we show that for the generic continuous maps of the interval and circle which preserve the lebesgue measure it holds for each k $ \ ge $ 1 that the set of periodic points of period k is a cantor set of hausdorff dimension zero and of upper box dimension one. furthermore, building on this result, we show that there is a dense collection of transitive lebesgue measure preserving interval map whose periodic points have full lebesgue measure and whose periodic points of period k have positive measure for each k $ \ ge $ 1. finally, we show that the generic continuous maps of the interval which preserve the lebesgue measure satisfy the shadowing and periodic shadowing property. | arxiv:2103.14309 |
we look for solutions $ e : \ omega \ to \ mathbb { r } ^ 3 $ of the problem $ $ \ left \ { \ begin { aligned } & \ nabla \ times ( \ nabla \ times e ) + \ lambda e = | e | ^ { p - 2 } e & & \ quad \ text { in } \ omega & \ nu \ times e = 0 & & \ quad \ text { on } \ partial \ omega \ end { aligned } \ right. $ $ on a bounded lipschitz domain $ \ omega \ subset \ mathbb { r } ^ 3 $, where $ \ nabla \ times $ denotes the curl operator in $ \ mathbb { r } ^ 3 $. the equation describes the propagation of the time - harmonic electric field $ \ re \ { e ( x ) e ^ { i \ omega t } \ } $ in a nonlinear isotropic material $ \ omega $ with $ \ lambda = - \ mu \ varepsilon \ omega ^ 2 \ leq 0 $, where $ \ mu $ and $ \ varepsilon $ stand for the permeability and the linear part of the permittivity of the material. the nonlinear term $ | e | ^ { p - 2 } e $ with $ p > 2 $ is responsible for the nonlinear polarisation of $ \ omega $ and the boundary conditions are those for $ \ omega $ surrounded by a perfect conductor. the problem has a variational structure and we deal with the critical values $ p $, for instance, in convex domains $ \ omega $ or in domains with $ \ mathcal { c } ^ { 1, 1 } $ boundary $ p = 6 = 2 ^ * $ is the sobolev critical exponent and we get the quintic nonlinearity in the equation. we show that there exist a cylindrically symmetric ground state solution and a finite number of cylindrically symmetric bound states depending on $ \ lambda \ leq 0 $. we develop a new critical point theory which allows to solve the problem, and which enables us to treat more general anisotropic media as well as other variational problems. | arxiv:1609.03989 |
we obtain a recursive formula answering the following question : how many irreducible, plane curves of degree d and ( geometric ) genus g pass through 3d - 1 + g general points in the plane? the formula is proved by studying suitable degenerations of plane curves. | arxiv:alg-geom/9608025 |
cross - domain sentiment classification ( cdsc ) is an importance task in domain adaptation and sentiment classification. due to the domain discrepancy, a sentiment classifier trained on source domain data may not works well on target domain data. in recent years, many researchers have used deep neural network models for cross - domain sentiment classification task, many of which use gradient reversal layer ( grl ) to design an adversarial network structure to train a domain - shared sentiment classifier. different from those methods, we proposed hierarchical attention generative adversarial networks ( hagan ) which alternately trains a generator and a discriminator in order to produce a document representation which is sentiment - distinguishable but domain - indistinguishable. besides, the hagan model applies bidirectional gated recurrent unit ( bi - gru ) to encode the contextual information of a word and a sentence into the document representation. in addition, the hagan model use hierarchical attention mechanism to optimize the document representation and automatically capture the pivots and non - pivots. the experiments on amazon review dataset show the effectiveness of hagan. | arxiv:1903.11334 |
the efficiency of a code is estimated by its redundancy $ r $, while the complexity of a code is estimated by its average delay $ \ bar n $. in this work we construct word - based codes, for which $ r \ lesssim \ bar n ^ { - 5 / 3 } $. therefore, word - based codes can attain the same redundancy as block - codes while being much less complex. we also consider uniform on the output codes, the benefit of which is the lack of a running synchronization error. for such codes $ \ bar n ^ { - 1 } \ lesssim r \ lesssim \ bar n ^ { - 1 } $, except for a case when all input symbols are equiprobable, when $ r \ leqslant \ bar n ^ { - 2 } $ for infinitely many $ \ bar n $. | arxiv:0712.0097 |
nearly magnetic metals often have layered lattice structures, consisting of coupled planes. in such a situation, physical properties will display, upon decreasing temperature or energy, a dimensional crossover from two - dimensional ( 2d ) to three - dimensional ( 3d ) behavior, which is particularly interesting near quantum criticality. here we study this crossover in thermodynamics using a suitably generalized landau - ginzburg - wilson approach to the critical behavior, combined with renormalization group techniques. we focus on two experimentally relevant cases : the crossover from a 2d to a 3d antiferromagnet, and the crossover from a 2d ferromagnet to a 3d antiferromagnet. we discuss the location of phase boundary and crossover lines and determine the crossover functions for important thermodynamic quantities. as naive scaling does not apply at and above the upper critical dimension, two crossover scales arise which can be associated with separate dimensional crossovers of classical and quantum fluctuations, respectively. in particular, we find an intermediate regime with novel power laws where the quantum fluctuations still have a 2d and the classical fluctuations already have a 3d character. for the ferromagnet - to - antiferromagnet crossover, the mismatch of the dynamical exponents between the 2d and 3d regimes leads to an even richer crossover structure, with an interesting 2d non - critical regime sandwiched between two critical regimes. for all cases, we find that thermal expansion and compressibility are particularly sensitive probes of the dimensional crossover. finally, we relate our results to experiments on the quantum critical heavy - fermion metals cecu ( 6 - x ) au ( x ), ybrh ( 2 ) si ( 2 ) and cecoin ( 5 ). | arxiv:0808.0616 |
samples consisting of one ferromagnetic and one diamagnetic component which are immiscible at the thermodynamic equilibrium ( co - cu, fe - cu, fe - ag ) are processed by high - pressure torsion at various compositions. the received microstructures are investigated by electron microscopy and synchrotron x - ray diffraction, showing a microstructural saturation. results gained from microstructural investigations are correlated to magnetometry data. the co - cu samples show mainly ferromagnetic behavior and a decrease in coercivity with increasing co - content. the saturation microstructure of fe - cu samples is found to be dual phase. results of magnetic measurements also revealed the occurrence of two different magnetic phases in this system. for fe - ag, the microstructural and magnetic results indicate that no intermixing between the elemental phases takes place. | arxiv:2009.02939 |
since chatgpt works so well, are we on the cusp of solving science with ai? is not alphafold2 suggestive that the potential of llms in biology and the sciences more broadly is limitless? can we use ai itself to bridge the lack of data in the sciences in order to then train an ai? herein we present a discussion of these topics. | arxiv:2312.00818 |
we quantify how squeezed light can reduce quantum measurement noise to levels below the standard quantum limit in impulse measurements with mechanical detectors. the broadband nature of the signal implies that frequency - dependent squeezing performs better than frequency - independent squeezing. we calculate the optimal scaling of the impulse sensitivity with the squeezing strength, and quantify degradations due to photodetection losses. even for lossless measurement, we find there exists a fundamental limit to the benefit of squeezing that depends only on the system ' s mechanical properties. | arxiv:2502.05168 |
we extend the argument that spacetimes generated by two timelike particles in d = 3 gravity ( or equivalently by parallel - moving cosmic strings in d = 4 ) permit closed timelike curves ( ctc ) only at the price of misner identifications that correspond to unphysical boundary conditions at spatial infinity and to a tachyonic center of mass. here we analyze geometries one or both of whose sources are lightlike. we make manifest both the presence of ctc at spatial infinity if they are present at all, and the tachyonic character of the system : as the total energy surpasses its tachyonic bound, ctc first begin to form at spatial infinity, then spread to the interior as the energy increases further. we then show that, in contrast, ctc are entirely forbidden in topologically massive gravity for geometries generated by lightlike sources. | arxiv:gr-qc/9210012 |
currently, self - induced inaln core - shell nanorods enjoy an advanced stage of accumulation of experimental data from their growth and characterization as well as a comprehensive understanding of their formation mechanism by the ab initio modeling based on synthetic growth concept. however, their electronic and optical properties, on which most of their foreseen applications are expected to depend, have not been investigated comprehensively. $ g _ 0w _ 0 $ is currently regarded as a gold - standard methodology with quasi - particle corrections to calculate electronic properties of materials in general. it is also the starting point for higher - order methods that study excitonic effects, such as those based on the bethe - salpeter equation. one major drawback of $ g _ 0w _ 0 $, however, is its computational cost, much higher than density - functional theory ( dft ). therefore, in many applications, it is highly desirable to answer the question of how well approaches based on dft, such as e. g. lda, lda - 1 / 2, and mbj, can approximately reproduce $ g _ 0w _ 0 $ results with respect to the electronic and optical properties. thus, the purpose of the present paper is to investigate how the dft - based methodologies lda, lda - 1 / 2, and mbj can be used as tools to approximate $ g _ 0w _ 0 $ in studies of the electronic and optical properties of scaled down models of core - shell inaln nanorods. for these systems, we observed that band gaps, density of states, dielectric functions, refractive indexes, absorption and reflectance coefficients are reasonably well described by lda - 1 / 2 and mbj when compared to $ g _ 0w _ 0 $, however, at a much more favorable computational cost. | arxiv:2309.14889 |
one of the very first steps astronomers working in stellar physics perform to advance in their studies, is to determine the most common / relevant physical parameters of the objects of study ( effective temperature, bolometric luminosity, surface gravity, etc. ). different methodologies exist depending on the nature of the data, intrinsic properties of the objects, etc. one common approach is to compare the observational data with theoretical models passed through some simulator that will leave in the synthetic data the same imprint than the observational data carries, and see what set of parameters reproduce the observations best. even in this case, depending on the kind of data the astronomer has, the methodology changes slightly. after parameters are published, the community tend to quote, praise and criticize them, sometimes paying little attention on whether the possible discrepancies come from the theoretical models, the data themselves or just the methodology used in the analysis. in this work we perform the simple, yet interesting, exercise of comparing the effective temperatures obtained via sed and more detailed spectral fittings ( to the same grid of models ), of a sample of well known and characterized young m - type objects members to different star forming regions and show how differences in temperature of up to 350 k can be expected just from the difference in methodology / data used. on the other hand we show how these differences are smaller for colder objects even when the complexity of the fit increases like for example introducing differential extinction. to perform this exercise we benefit greatly from the framework offered by the virtual observatory. | arxiv:1407.0595 |
as a seminal tool in self - supervised representation learning, contrastive learning has gained unprecedented attention in recent years. in essence, contrastive learning aims to leverage pairs of positive and negative samples for representation learning, which relates to exploiting neighborhood information in a feature space. by investigating the connection between contrastive learning and neighborhood component analysis ( nca ), we provide a novel stochastic nearest neighbor viewpoint of contrastive learning and subsequently propose a series of contrastive losses that outperform the existing ones. under our proposed framework, we show a new methodology to design integrated contrastive losses that could simultaneously achieve good accuracy and robustness on downstream tasks. with the integrated framework, we achieve up to 6 \ % improvement on the standard accuracy and 17 \ % improvement on the robust accuracy. | arxiv:2112.04468 |
we demonstrate fractal noise in the quantum evolution of wave packets moving either ballistically or diffusively in periodic and quasiperiodic tight - binding lattices, respectively. for the ballistic case with various initial superpositions we obtain a space - time self - affine fractal $ \ psi ( x, t ) $ which verify the predictions by berry for " a particle in a box ", in addition to quantum revivals. for the diffusive case self - similar fractal evolution is also obtained. these universal fractal features of quantum theory might be useful in the field of quantum information, for creating efficient quantum algorithms, and can possibly be detectable in scattering from nanostructures. | arxiv:quant-ph/0310125 |
it is well known that if the most energetic cosmic rays ( $ e > 10 ^ { 20 } $ ev ) were protons then their acceleration sites should possess some extreme properties, including gigantic luminosity. as no stationary sources with such properties are known in the local ( $ d < 200 $ mpc ) neighborhood of the milky way, it is highly likely that the uhecr acceleration takes place in some transient events. in this paper we investigate scenario where the uhecrs are produced in strong agn flares. using more than 7 years of the fermi - lat observations we select candidate flares and, using correlation between jet kinetic luminosity and its bolometric luminosity, estimate local kinetic emissivity of giant agn flares : $ \ mathcal { l } \ sim3. 7 \ times10 ^ { 44 } \ mathrm { erg ~ mpc ^ { - 3 } ~ { yr ^ { - 1 } } } $. this value is about an order of magnitude larger than the emissivity in the crs with $ e > 10 ^ { 20 } $ ev, thus making this scenario feasible, if the uhecr escape spectrum is rather hard and / or narrow. this shape of spectrum is predicted in a number of present models of strong relativistic collisionless shocks. also the scenario of acceleration in agn flares can accommodate constraints coming from the observed arrival distribution of uhecrs. finally, we demonstrate that in case of heavier uhecr composition all the constraints are greatly relaxed. | arxiv:1804.01064 |
the semantically interactive radiance field has long been a promising backbone for 3d real - world applications, such as embodied ai to achieve scene understanding and manipulation. however, multi - granularity interaction remains a challenging task due to the ambiguity of language and degraded quality when it comes to queries upon object components. in this work, we present fmlgs, an approach that supports part - level open - vocabulary query within 3d gaussian splatting ( 3dgs ). we propose an efficient pipeline for building and querying consistent object - and part - level semantics based on segment anything model 2 ( sam2 ). we designed a semantic deviation strategy to solve the problem of language ambiguity among object parts, which interpolates the semantic features of fine - grained targets for enriched information. once trained, we can query both objects and their describable parts using natural language. comparisons with other state - of - the - art methods prove that our method can not only better locate specified part - level targets, but also achieve first - place performance concerning both speed and accuracy, where fmlgs is 98 x faster than lerf, 4 x faster than langsplat and 2. 5 x faster than legaussians. meanwhile, we further integrate fmlgs as a virtual agent that can interactively navigate through 3d scenes, locate targets, and respond to user demands through a chat interface, which demonstrates the potential of our work to be further expanded and applied in the future. | arxiv:2504.08581 |
we calculate the total and differential quasielastic cross sections for neutrino and antineutrino scattering on nucleons using up to date fits to the nucleon elastic electromagnetic form factors $ g _ e ^ p $, $ g _ e ^ n $, $ g _ m ^ p $, $ g _ m ^ n $, and weak and pseudoscalar form factors. we find that using the updated non - zero value of $ g _ e ^ n $ has a significant effect on both the total and differential neutrino and antineutrino quasielastic cross sections. previous extractions of the weak axial form factor from neutrino scattering data are sensitive to the assumptions that were used for the vector form factors. we perform a re - analysis of previous neutrino data using updated form factors and obtain updated value of the axial vector mass. | arxiv:hep-ex/0308005 |
we investigate the thermal physics of a bose - hubbard model with rashba spin - orbit coupling starting from a strong coupling mean - field ground state. the essential role of the spin - orbit coupling $ \ left ( \ gamma \ right ) $ is to promote condensation of the bosons at a finite wavevector $ { k } _ { 0 } $. we find that the bosons display either homogeneous or phase - twisted or orbital ordered superfluid phases, depending on $ \ gamma $ and the inter - species interaction strength $ \ lambda $. we show that an increase of $ \ gamma $ leads to suppression of the critical interaction $ u _ c $ for the superfluid to mott insulator transition in the ground state, and a reduction of the $ t _ c $ for superfluid to bose - liquid transition at a fixed interaction. we capture the thermal broadening in the momentum distribution function, and the real space profiles of the thermally disordered magnetic textures, including their homogenization for $ t \ gtrsim t _ { c } $. we provide a landau theory based description of the ground state phase boundaries and thermal transition scales, and discuss experiments which can test our theory. | arxiv:1901.10672 |
the complete spectrum of plasmons of the two interpenetrating plasma streams is found in a closed analytic form. the orientation of the wave vector with respect to the stream direction is arbitrary and the plasmas, which are assumed to be collisionless and spatially homogeneous, can be nonrelativistic, relativistic or even ultrarelativistic. our results apply to the electromagnetic plasma of electrons and passive ions and to the quark - gluon plasma governed by qcd. | arxiv:1503.08861 |
the present work investigates surrogate model - based optimization for real - time curbside traffic management operations. an optimization problem is formulated to minimize the congestion on roadway segments caused by vehicles stopping on the segment ( e. g., ride - hailing or delivery operations ) and implemented in a model predictive control framework. a hybrid simulation approach where main traffic flows interact with individually modeled stopping vehicles is adopted. due to its non - linearity, the optimization problem is coupled with a meta - heuristic. however, because simulations are time expensive and hence unsuitable for real - time control, a trained surrogate model that takes the decision variables as inputs and approximates the objective function is employed to replace the simulation within the meta - heuristic algorithm. several modeling techniques ( i. e., linear regression, polynomial regression, neural network, radial basis network, regression tree ensemble, and gaussian process regression ) are compared based on their accuracy in reproducing solutions to the problem and computational tractability for real - time control under different configurations of simulation parameters. it is found that gaussian process regression is the most suited for use as a surrogate model for the given problem. finally, a realistic application with multiple ride - hailing vehicle operations is presented. the proposed approach for controlling the stop positions of vehicles is able to achieve an improvement of 20. 65 % over the uncontrolled case. the example shows the potential of the proposed approach in reducing the negative impacts of stopping vehicles and favorable computational properties. | arxiv:2310.03883 |
we study intersecting d - brane models, that describe at low energies a two dimensional chiral fermion theory localized at the intersection. the fermions are coupled to gauge fields in the bulk. the resulting low energy theory is equivalent to the gross - neveu model with dynamical chiral symmetry breaking. no nambu - goldstone boson associated with spontaneously broken symmetries appears in two dimensional field theories. in the present work we discuss solvable models with the same basic dynamics of the dual gross - neveu model. the disappearance of the nambu - goldstone boson is obtained from d - brane dynamics. the mechanism relies on the non - trivial dynamics of a gauge field due to anomaly inflow. | arxiv:hep-th/0611331 |
in this paper we present an approach to determine the smallest possible number of neurons in a layer of a neural network in such a way that the topology of the input space can be learned sufficiently well. we introduce a general procedure based on persistent homology to investigate topological invariants of the manifold on which we suspect the data set. we specify the required dimensions precisely, assuming that there is a smooth manifold on or near which the data are located. furthermore, we require that this space is connected and has a commutative group structure in the mathematical sense. these assumptions allow us to derive a decomposition of the underlying space whose topology is well known. we use the representatives of the $ k $ - dimensional homology groups from the persistence landscape to determine an integer dimension for this decomposition. this number is the dimension of the embedding that is capable of capturing the topology of the data manifold. we derive the theory and validate it experimentally on toy data sets. | arxiv:2004.02881 |
we introduce an extension to the protege ontology editor, which allows for discovering concept definitions, which are not explicitly present in axioms, but are logically implied by an ontology. the plugin supports ontologies formulated in the description logic el, which underpins the owl 2 el profile of the web ontology language and despite its limited expressiveness captures most of the biomedical ontologies published on the web. the developed tool allows to verify whether a concept can be defined using a vocabulary of interest specified by a user. in particular, it allows to decide whether some vocabulary items can be omitted in a formulation of a complex concept. the corresponding definitions are presented to the user and are provided with explanations generated by an ontology reasoner. | arxiv:1810.04363 |
the orbital angular momentum is one of the least understood of the spin characteristics of a proton. there are no direct ways to model the orbital angular momentum. however, the jz = 1 / 2 sum rule includes an angular momentum component and can provide indirect access to its properties. one of the other unknowns in the sum rule is the gluon polarization. we can define the gluon spin asymmetry in a proton as the ratio of the polarized to unpolarized gluon distributions. this can be written as a sum of a scale - invariant piece and a small scale - dependent term. the x - dependence of the asymmetry can be calculated and a suitable parametrization for scale - dependent term can be made to estimate this asymmetry. when combined with the measured unpolarized gluon density, this provides a model independent prediction for the polarized gluon distribution. this eliminates one unknown in the jz = 1 / 2 sum rule and allows a reasonable estimate for the size and evolution of the orbital angular momentum of the constituents. | arxiv:hep-ph/0601141 |
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