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we report a first case study of the phase diagram of 2 + 1 flavor strongly interacting matter in $ \ beta - $ equilibrium, using the polyakov $ - $ nambu $ - $ jona - lasinio model. physical characteristics of relevant thermodynamic observables have been discussed. a comparative analysis with the corresponding observables in the nambu - jona - lasinio model is presented. we find distinct differences between the models in terms of a number of thermodynamic quantities like the speed of sound, specific heat, various number densities as well as entropy. the present study is expected to give us a better insight into the role that the superdense matter created in heavy ion collision experiments play in our understanding of the properties of matter inside the core of supermassive stars in the universe.
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arxiv:1107.5941
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for a one - dimensional linear lattice, earlier work has shown how to systematically construct a slowly - decaying linear potential bearing a localized eigenmode embedded in the continuous spectrum. here, we extend this idea in two directions : the first one is in the realm of the discrete nonlinear schrodinger equation, where the linear operator of the schrodinger type is considered in the presence of a kerr focusing or defocusing nonlinearity and the embedded linear mode is continued into the nonlinear regime as a discrete solitary wave. the second case is the klein - gordon setting, where the presence of a cubic nonlinearity leads to the emergence of embedded - in - the - continuum discrete breathers. in both settings, it is seen that the stability of the modes near the linear limit turns into instability as nonlinearity is increased past a critical value, leading to a dynamical delocalization of the solitary wave ( or breathing ) state. finally, we suggest a concrete experiment to observe these embedded modes using a bi - inductive electrical lattice.
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arxiv:2108.00193
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the central two - pion exchange nn potential at large distances is studied in the framework of relativistic chiral symmetry and related directly to the nucleon scalar form factor, which describes the mass density of its pion cloud. this relationship is well supported by phenomenology and allows the dependence of the asymptotic potential on the nucleon mass to be assessed. results in the heavy baryon limit are about 25 % larger than those corresponding to the empirical nucleon mass in the region of physical interest. this indicates that it is very important to keep this mass finite in precise descriptions of the nn system and supports the efficacy of the relativistic chiral framework. one also estimates the contribution of subleading effects and presents a simple discussions of the role of the quark condensate in this problem.
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arxiv:nucl-th/0009001
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as the central nerve of the intelligent vehicle control system, the in - vehicle network bus is crucial to the security of vehicle driving. one of the best standards for the in - vehicle network is the controller area network ( can bus ) protocol. however, the can bus is designed to be vulnerable to various attacks due to its lack of security mechanisms. to enhance the security of in - vehicle networks and promote the research in this area, based upon a large scale of can network traffic data with the extracted valuable features, this study comprehensively compared fully - supervised machine learning with semi - supervised machine learning methods for can message anomaly detection. both traditional machine learning models ( including single classifier and ensemble models ) and neural network based deep learning models are evaluated. furthermore, this study proposed a deep autoencoder based semi - supervised learning method applied for can message anomaly detection and verified its superiority over other semi - supervised methods. extensive experiments show that the fully - supervised methods generally outperform semi - supervised ones as they are using more information as inputs. typically the developed xgboost based model obtained state - of - the - art performance with the best accuracy ( 98. 65 % ), precision ( 0. 9853 ), and roc auc ( 0. 9585 ) beating other methods reported in the literature.
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arxiv:2207.10286
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we present a scheme of probabilistic dense coding via a quantum channel of non - maximally entangled three - particle state. the quantum dense coding will be succeeded with a certain probability if the sender introduces an auxiliary particle and performs a collective unitary transformation. furthermore, the average information transmitted in this scheme is calculated.
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arxiv:0902.3711
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we investigate knight shift and nuclear spin relaxation rate in a charge ordered state of the one - dimensional extended hubbard model with a quarter filled band by using rpa around the mean - field solution. it is shown that both quantities show splitting below the critical temperature of the charge order, as is experimentally observed. the relationship between the mount of the splitting in the both quantities and the charge disproportionation rate is discussed.
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arxiv:cond-mat/0511150
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considered in this paper is the modified camassa - holm equation with cubic nonlinearity, which is integrable and admits the single peaked solitons and multi - peakon solutions. the short - wave limit of this equation is known as the short - pulse equation. the main investigation is the cauchy problem of the modified camassa - holm equation with qualitative properties of its solutions. it is firstly shown that the equation is locally well - posed in a range of the besov spaces. the blow - up scenario and the lower bound of the maximal time of existence are then determined. a blow - up mechanism for solutions with certain initial profiles is described in detail and nonexistence of the smooth traveling wave solutions is also demonstrated. in addition, the persistence properties of the strong solutions for the equation are obtained.
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arxiv:1108.5368
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we derive the exact effective superpotential in 4d, n = 1 supersymmetric su ( 2 ) gauge theories with $ n _ a $ triplets and $ 2n _ f $ doublets of matter superfields. we find the quantum vacua of these theories ; the equations of motion ( for $ n _ a = 1 $ ) can be reorganized into the singularity conditions of an elliptic curve. from the phase transition points to the coulomb branch, we find the exact abelian gauge couplings, $ \ tau $, for arbitrary bare masses and yukawa couplings. we thus { \ em derive } the result that $ \ tau $ is a section of an $ sl ( 2, \ z ) $ bundle over the moduli space and over the parameters space of bare masses and yukawa couplings. for $ n _ c > 2 $, we derive the exact effective superpotential in branches of supersymmetric $ su ( n _ c ) $ gauge theories with one supermultiplet in the adjoint representation ( $ n _ a = 1 $ ) and zero or one flavor ( $ n _ f = 0, 1 $ ). we find the quantum vacua of these theories ; the equations of motion can be reorganized into the singularity conditions of a genus $ n _ c - 1 $ hyperelliptic curve. finally, we present the effective superpotential in the $ n _ a $, $ n _ f < n _ c $ cases.
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arxiv:hep-th/9509130
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it is shown that the $ w _ { 1 + \ infty } $ algebra is nothing but the simplest subalgebra of a $ q $ - discretized \ vi \ algebra, in the language of the kp hierarchy explicitly.
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arxiv:hep-th/9411027
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the su - schrieffer - heeger ( ssh ) model lays the foundation of many important concepts in quantum topological matters. since it tells one that topological states may be distinguished by abelian geometric phases, a question naturally arises as to what happens if one assembles two topologically distinct states. here, we show that a spin - dependent double - well optical lattice allows one to couple two topologically distinct ssh chains in the bulk and realise a glided - two - leg ssh model that respects the glide reflection symmetry. such model gives rise to intriguing quantum phenomena beyond the paradigm of a traditional ssh model. it is characterised by wilson line that requires non - abelian berry connections, and the interplay between the glide symmetry and interaction automatically leads to charge fractionalisation without jointing two lattice potentials at an interface. our work demonstrates the power of ultracold atoms to create new theoretical models for studying topological matters.
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arxiv:1604.06292
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it has often been proposed that the formation of large - scale motion ( or bulges ) is a consequence of successive mergers and / or growth of near - wall hairpin vortices. in the present study, we report our direct observation that large - scale motion is generated by an instability of an ` amplified ' streaky motion in the outer region ( i. e. very - large - scale motion ). we design a numerical experiment in turbulent channel flow up to $ re _ \ tau \ simeq 2000 $ where a streamwise - uniform streaky motion is artificially driven by body forcing in the outer region computed from the previous linear theory ( hwang \ & cossu, j. fluid mech., vol. 664, 2015, pp. 51 - - 73 ). as the forcing amplitude is increased, it is found that an energetic streamwise vortical structure emerges at a streamwise wavelength of $ \ lambda _ x / h \ simeq 1 - 5 $ ( $ h $ is the half - height of the channel ). the application of dynamic mode decomposition and the examination of turbulence statistics reveal that this structure is a consequence of the sinuous - mode instability of the streak, a sub - process of the self - sustaining mechanism of the large - scale outer structures. it is also found that the statistical features of the vortical structure are remarkably similar to those of the large - scale motion in the outer region. finally, it is proposed that the largest streamwise length of the streak instability determines the streamwise length scale of very - large - scale motion.
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arxiv:1709.06782
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dynamic network reconstruction has been shown to be challenging due to the requirements on sparse network structures and network identifiability. the direct parametric method ( e. g., using arx models ) requires a large amount of parameters in model selection. amongst the parametric models, only a restricted class can easily be used to address network sparsity without rendering the optimization problem intractable. to overcome these problems, this paper presents a state - space - based method, which significantly reduces the number of unknown parameters in model selection. furthermore, we avoid various difficulties arising in gradient computation by using the expectation minimization ( em ) algorithm instead. to enhance network sparsity, the prior distribution is constructed by using the sparse bayesian learning ( sbl ) approach in the m - step. to solve the sbl problem, another em algorithm is embedded, where we impose conditions on network identifiability in each iteration. in a sum, this paper provides a solution to reconstruct dynamic networks that avoids the difficulties inherent to gradient computation and simplifies the model selection.
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arxiv:1811.08677
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we investigate non - adaptive methods of deep relu neural network approximation in bochner spaces $ l _ 2 ( { \ mathbb u } ^ \ infty, x, \ mu ) $ of functions on $ { \ mathbb u } ^ \ infty $ taking values in a separable hilbert space $ x $, where $ { \ mathbb u } ^ \ infty $ is either $ { \ mathbb r } ^ \ infty $ equipped with the standard gaussian probability measure, or $ { \ mathbb i } ^ \ infty : = [ - 1, 1 ] ^ \ infty $ equipped with the jacobi probability measure. functions to be approximated are assumed to satisfy a certain weighted $ \ ell _ 2 $ - summability of the generalized chaos polynomial expansion coefficients with respect to the measure $ \ mu $. we prove the convergence rate of this approximation in terms of the size of approximating deep relu neural networks. these results then are applied to approximation of the solution to parametric elliptic pdes with random inputs for the lognormal and affine cases.
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arxiv:2111.05854
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quasiparticles are physically motivated mathematical constructs for simplifying the seemingly complicated many - body description of solids. a complete understanding of their dynamics and the nature of the effective interactions between them provides rich information on real material properties at the microscopic level. in this work, we explore the dynamics and interactions of magnon quasiparticles in a ferromagnetic spin - 1 heisenberg chain with easy - axis onsite anisotropy, a model relevant for the explanation of recent terahertz optics experiments on ninb $ _ 2 $ o $ _ 6 $ [ p. chauhan et al., phys. rev. lett. 124, 037203 ( 2020 ) ], and nonequilibrium dynamics in ultracold atomic settings [ w. c. chung et al., phys. rev. lett. 126, 163203 ( 2021 ) ]. we build a picture for the properties of clouds of a few magnons with the help of exact diagonalization and density matrix renormalization group calculations supported by physically motivated jastrow wavefunctions. we show how the binding energy of magnons effectively reduces with their number and explain how this energy scale is of direct relevance for dynamical magnetic susceptibility measurements. this understanding is used to make predictions for ultracold - atomic platforms which are ideally suited to study the thermalization of multimagnon states. we simulate the nonequilibrium dynamics of these chains using the matrix product state based time - evolution block decimation algorithm and explore the dependence of revivals and thermalization on magnon density and easy - axis onsite anisotropy ( which controls the strength of effective magnon interactions ). we observe behaviors akin to those reported for many - body quantum scars which we explain with an analytic approximation that is accurate in the limit of small anisotropy.
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arxiv:2107.09105
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this whitepaper offers an overview of the ethical considerations surrounding research into or with large language models ( llms ). as llms become more integrated into widely used applications, their societal impact increases, bringing important ethical questions to the forefront. with a growing body of work examining the ethical development, deployment, and use of llms, this whitepaper provides a comprehensive and practical guide to best practices, designed to help those in research and in industry to uphold the highest ethical standards in their work.
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arxiv:2410.19812
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the underactuated vehicles are apposite for the long - term deployment and data collection in spatiotemporally varying marine environments. however, these vehicles need to estimate their positions ( states ) with intrinsic sensing in their long - term trajectories. in previous studies, autonomous underwater vehicles have commonly used vision and range sensors for autonomous state estimation. inspired by the intrinsic sensing and the persistent deployment, we investigate the localization problem ( state estimation ) for an inexpensive and underactuated drifting vehicle called a drifter. in this paper, we present a localization method for the drifter making use of the observations of a proprioceptive sensor, i. e., compass. we create the water flow pattern within a given region from ocean model predictions, develop a stochastic motion model, and analyze the persistent water flow behavior. given a distribution of initial deployment states of the drifter at a particular depth of the water column within the region and the water flow pattern, our method finds attractors and their transient groups at the given depth as the persistent behavior of the water flow. a most - likely localized trajectory of the drifter for a sequence of compass observations is generated based on the persistent behavior of the water flow and hidden markov model. our simulation results based on data from ocean model predictions substantiate good performance of our proposed localization method with a low error rate of the state estimation in the long - term trajectory of the drifter.
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arxiv:1808.05164
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the paper studies a multiserver retrial queueing system with $ m $ servers. arrival process is a point process with strictly stationary and ergodic increments. a customer arriving to the system occupies one of the free servers. if upon arrival all servers are busy, then the customer goes to the secondary queue, orbit, and after some random time retries more and more to occupy a server. a service time of each customer is exponentially distributed random variable with parameter $ \ mu _ 1 $. a time between retrials is exponentially distributed with parameter $ \ mu _ 2 $ for each customer. using a martingale approach the paper provides an analysis of this system. the paper establishes the stability condition and studies a behavior of the limiting queue - length distributions as $ \ mu _ 2 $ increases to infinity. as $ \ mu _ 2 \ to \ infty $, the paper also proves the convergence of appropriate queue - length distributions to those of the associated ` usual ' multiserver queueing system without retrials. an algorithm for numerical solution of the equations, associated with the limiting queue - length distribution of retrial systems, is provided.
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arxiv:math/0505046
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properties of a single impurity in a one - dimensional fermi gas are investigated in homogeneous and trapped geometries. in a homogeneous system we use mcguire ' s expression [ j. b. mcguire, j. math. phys. 6, 432 ( 1965 ) ] to obtain interaction and kinetic energies, as well as the local pair correlation function. the energy of a trapped system is obtained ( i ) by generalizing mcguire expression ( ii ) within local density approximation ( iii ) using perturbative approach in the case of a weakly interacting impurity and ( iv ) diffusion monte carlo method. we demonstrate that a closed formula based on the exact solution of the homogeneous case provides a precise estimation for the energy of a trapped system for arbitrary coupling constant of the impurity even for a small number of fermions. we analyze energy contributions from kinetic, interaction and potential components, as well as spatial properties such as the system size. finally, we calculate the frequency of the breathing mode. our analysis is directly connected and applicable to the recent experiments in microtraps.
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arxiv:1303.7007
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to date, magnetic proximity effect ( mpe ) has only been conclusively observed in ferromagnet ( fm ) based systems. we report the observation of anomalous hall effect and anisotropic magnetoresistance in angular dependent magnetoresistance ( admr ) measurements in pt on antiferromagnetic ( af ) $ \ alpha $ - fe $ _ 2 $ o $ _ 3 $ ( 0001 ) epitaxial films at 10 k, which provide evidence for the mpe. the n \ ' eel order of $ \ alpha $ - fe $ _ 2 $ o $ _ 3 $ and the induced magnetization in pt show a unique admr compared with all other fm and af systems. a macrospin response model is established and can explain the af spin configuration and all main admr features in the pt / $ \ alpha $ - fe $ _ 2 $ o $ _ 3 $ bilayers.
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arxiv:1906.04395
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we study asymptotic properties of conditional least squares estimators for the drift parameters of two - factor affine diffusions based on continuous time observations. we distinguish three cases : subcritical, critical and supercritical. for all the drift parameters, in the subcritical and supercritical cases, asymptotic normality and asymptotic mixed normality is proved, while in the critical case, non - standard asymptotic behavior is described.
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arxiv:1703.02376
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we present the jwst discovery of a highly - extincted ( $ a _ v \ sim52 $ ) candidate brown dwarf ( $ \ sim0. 018 $ m $ _ \ odot $ ) in the outskirts of the trapezium cluster that appears to be coincident with the end of a $ \ sim 1700 \, $ au long, remarkably uniformly wide, dark trail that broadens only slightly at the end opposite the point source. we examine whether a dusty trail associated with a highly - extincted brown dwarf could plausibly be detected with jwst and explore possible origins. we show that a dusty trail associated with the brown dwarf could be observable if dust within it is larger than that in the ambient molecular cloud. for example, if the ambient cloud has a standard $ \ sim0. 25 $ $ \ mu $ m maximum grain size and the trail contains micron - sized grains, then the trail will have a scattering opacity over an order of magnitude larger compared to the surroundings in nircam short - wavelength filters. we use a simple model to show that a change in maximum grain size can reproduce the high $ a _ v $ and the multi - filter nircam contrast seen between the trail and its surroundings. we propose and explore two possible mechanisms that could be responsible for the trail : i ) a weak fuv radiation - driven wind from the circum - brown dwarf disc due to the o stars in the region and ii ) a bondi - hoyle - lyttleton accretion wake. the former would be the most distant known case of the trapezium stars ' radiation driving winds from a disc, and the latter would be the first known example of ` ` late ' ' infall from the interstellar medium onto a low mass object in a high - mass star - forming region.
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arxiv:2502.04447
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we analyze the stochastic scaling laws arising in the invicid limit of the decaying solutions of the burgers equation. the linear scaling of the velocity structure functions is shown to reflect the domination by shocks of the long - time asymptotics. we exhibit new self - similar statistics of solutions describing phases with diluted shocks. some speculations are included on the nature of systems whose large time behavior is described by the new statistics.
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arxiv:chao-dyn/9805002
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tomography of single - particle - resolved detectors is of primary importance for characterizing particle correlations with applications in quantum metrology, quantum simulation and quantum computing. however, it is a non - trivial task in practice due to the unavoidable presence of noise that affects the measurement but does not originate from the detector. in this work, we address this problem for a three - dimensional single - atom - resolved detector where shot - to - shot atom number fluctuations are a central issue to perform a quantum detector tomography. we overcome this difficulty by exploiting the parallel measurement of counting statistics in sub - volumes of the detector, from which we evaluate the effect of shot - to - shot fluctuations and perform a local tomography of the detector. in addition, we illustrate the validity of our method from applying it to gaussian quantum states with different number statistics. finally, we show that the response of micro - channel plate detectors is well - described from using a binomial distribution with the detection efficiency as a single parameter.
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arxiv:2405.01211
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while nuclear magnetic resonance ( nmr ) provides valuable insights into the local environment of many nuclei, the unambiguous interpretation of the signal in terms of microscopic dynamics is often difficult, particularly when the quadrupolar relaxation mechanism comes into play. here, we investigate the quadrupolar nmr relaxation of cations and anions in aqueous alcaline and alcaline - earth chlorides solutions, across a broad range of salt concentrations. using a combination of dft calculations and classical molecular dynamics simulations, we compute the electric field gradient ( efg ) fluctuations over the relevant time scales. predicted nmr relaxation rates are in good agreement with experiments from the literature. as previously reported for nacl, we find that the increase in relaxation rate with salt concentration is primarily driven by the slowing of efg fluctuations, while changes in the static variance of the efg play a minor role. we highlight some specific features for smaller and divalent cations compared to the other monovalent ones. additionally, we assess the relevance of the stokes - einstein - debye model, frequently used to analyze nmr relaxation experiments, for these aqueous electrolytes, and highlight the link between the collective dynamics of the liquid underlying the efg fluctuations at the ion positions and the stress fluctuations. our results generalize observations for na $ ^ + $ in aqueous nacl solutions, showing that models assuming a viscous model of the solvent dynamics are insufficient to describe efg fluctuations in these systems and illustrate the relevance of molecular simulations to interpret nmr relaxation experiments in terms of microscopic dynamics.
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arxiv:2502.06409
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nonlinear data visualization using t - distributed stochastic neighbor embedding ( t - sne ) enables the representation of complex single - cell transcriptomic landscapes in two or three dimensions to depict biological populations accurately. however, t - sne often fails to account for uncertainties in the original dataset, leading to misleading visualizations where cell subsets with noise appear indistinguishable. to address these challenges, we introduce uncertainty - aware t - sne ( ut - sne ), a noise - defending visualization tool tailored for uncertain single - cell rna - seq data. by creating a probabilistic representation for each sample, our ut - sne accurately incorporates noise about transcriptomic variability into the visual interpretation of single - cell rna sequencing data, revealing significant uncertainties in transcriptomic variability. through various examples, we showcase the practical value of ut - sne and underscore the significance of incorporating uncertainty awareness into data visualization practices. this versatile uncertainty - aware visualization tool can be easily adapted to other scientific domains beyond single - cell rna sequencing, making them valuable resources for high - dimensional data analysis.
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arxiv:2410.00473
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the influence of the tip - substrate bias induced electrical field in a scanning tunneling spectroscopy experiment on colloidal inas nanocrystals has been studied. calculating the stark induced splitting of the degenerate 1p _ e state perturbatively within a particle - in - a - sphere model, revealed a possible explanation of recently published experimental wave function mapping data by millo et al. ( ref. 1 ).
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arxiv:cond-mat/0108221
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ad hoc networks are the special networks formed for specific applications. operating in ad - hoc mode allows all wireless devices within range of each other to discover and communicate in a peer - to - peer fashion without involving central access points. many routing protocols like aodv, dsr etc have been proposed for these networks to find an end to end path between the nodes. these routing protocols are prone to attacks by the malicious nodes. there is a need to detect and prevent these attacks in a timely manner before destruction of network services.
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arxiv:1405.5320
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the guesswork of a classical - quantum channel quantifies the cost incurred in guessing the state transmitted by the channel when only one state can be queried at a time, maximized over any classical pre - processing and minimized over any quantum post - processing. for arbitrary - dimensional covariant classical - quantum channels, we prove the invariance of the optimal pre - processing and the covariance of the optimal post - processing. in the qubit case, we compute the optimal guesswork for the class of so - called highly symmetric informationally complete classical - quantum channels.
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arxiv:2306.12633
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in conical refraction ( cr ), a focused gaussian input beam passing through a biaxial crystal and parallel to one of the optic axes is transformed into a pair of concentric bright rings split by a dark ( poggendorff ) ring at the focal plane. here, we show the generation of a cr transverse pattern that does not present the poggendorff fine splitting at the focal plane, i. e. it forms a single light ring. this light ring is generated from a non - homogeneously polarized input light beam obtained by using a spatially inhomogeneous polarizer that mimics the characteristic cr polarization distribution. this polarizer allows modulating the relative intensity between the two cr light cones in accordance with the recently proposed dual - - cone model of the cr phenomenon. we show that the absence of interfering rings at the focal plane is caused by the selection of one of the two cr cones.
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arxiv:1505.04933
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this paper lays the foundation for determining the kodaira dimension of the projectivized strata of abelian differentials with prescribed zero and pole orders in large genus. we work with the moduli space of multi - scale differentials constructed in [ bcggm2 ] which provides an orbifold compactification of these strata. we establish the projectivity of the moduli space of multi - scale differentials, describe the locus of canonical singularities, and compute a series of effective divisor classes. moreover, we exhibit a perturbation of the canonical class which allows the corresponding pluri - canonical forms to extend over the locus of non - canonical singularities. as applications, we certify general type for strata with few zeros as well as for strata with equidistributed zero orders when g is sufficiently large. in particular, we show general type for the odd spin components of the minimal strata for g > 12.
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arxiv:2204.11943
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we examine the theoretical properties of enforcing priors provided by generative deep neural networks via empirical risk minimization. in particular we consider two models, one in which the task is to invert a generative neural network given access to its last layer and another in which the task is to invert a generative neural network given only compressive linear observations of its last layer. we establish that in both cases, in suitable regimes of network layer sizes and a randomness assumption on the network weights, that the non - convex objective function given by empirical risk minimization does not have any spurious stationary points. that is, we establish that with high probability, at any point away from small neighborhoods around two scalar multiples of the desired solution, there is a descent direction. hence, there are no local minima, saddle points, or other stationary points outside these neighborhoods. these results constitute the first theoretical guarantees which establish the favorable global geometry of these non - convex optimization problems, and they bridge the gap between the empirical success of enforcing deep generative priors and a rigorous understanding of non - linear inverse problems.
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arxiv:1705.07576
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analog audio effects and synthesizers often owe their distinct sound to circuit nonlinearities. faithfully modeling such significant aspect of the original sound in virtual analog software can prove challenging. the current work proposes a generic data - driven approach to virtual analog modeling and applies it to the fender bassman 56f - a vacuum - tube amplifier. specifically, a feedforward variant of the wavenet deep neural network is trained to carry out a regression on audio waveform samples from input to output of a spice model of the tube amplifier. the output signals are pre - emphasized to assist the model at learning the high - frequency content. the results of a listening test suggest that the proposed model accurately emulates the reference device. in particular, the model responds to user control changes, and faithfully restitutes the range of sonic characteristics found across the configurations of the original device.
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arxiv:1811.00334
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the source code of successful projects is evolving all the time, resulting in hundreds of thousands of code changes stored in source code repositories. this wealth of data can be useful, e. g., to find changes similar to a planned code change or examples of recurring code improvements. this paper presents diffsearch, a search engine that, given a query that describes a code change, returns a set of changes that match the query. the approach is enabled by three key contributions. first, we present a query language that extends the underlying programming language with wildcards and placeholders, providing an intuitive way of formulating queries that is easy to adapt to different programming languages. second, to ensure scalability, the approach indexes code changes in a one - time preprocessing step, mapping them into a feature space, and then performs an efficient search in the feature space for each query. third, to guarantee precision, i. e., that any returned code change indeed matches the given query, we present a tree - based matching algorithm that checks whether a query can be expanded to a concrete code change. we present implementations for java, javascript, and python, and show that the approach responds within seconds to queries across one million code changes, has a recall of 80. 7 % for java, 89. 6 % for python, and 90. 4 % for javascript, enables users to find relevant code changes more effectively than a regular expression - based search, and is helpful for gathering a large - scale dataset of real - world bug fixes.
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arxiv:2204.02787
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this paper considers a diffusion - based molecular communication system where the transmitter uses reaction shift keying ( rsk ) as the modulation scheme. we focus on the demodulation of rsk signal at the receiver. the receiver consists of a front - end molecular circuit and a back - end demodulator. the front - end molecular circuit is a set of chemical reactions consisting of multiple chemical species. the optimal demodulator computes the posteriori probability of the transmitted symbols given the history of the observation. the derivation of the optimal demodulator requires the solution to a specific bayesian filtering problem. the solution to this bayesian filtering problem had been derived for a few specific molecular circuits and specific choice ( s ) of observed chemical species. the derivation of such solution is also lengthy. the key contribution of this paper is to present a general solution to this bayesian filtering problem which can be applied to any molecular circuit and any choice of observed species.
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arxiv:1610.09785
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the fifth part of the ogle - iii catalog of variable stars presents 23 r crb ( rcb ) stars in the large magellanic cloud ( lmc ). 17 of these objects have been spectroscopically confirmed by previous studies, while 6 stars are new candidates for rcb variables. we publish the vi multi - epoch ogle photometry for all objects. we use the sample of carbon - rich long - period variables released in the previous part of this catalog to select objects with severe drops in luminosity, i. e. with the dy - per - like light curves. dy per stars are often related to r crb variables. we detect at least 600 candidates for dy per stars, mostly among dust enshrouded giants. we notice that our candidate dy per stars form a continuity with other carbon - rich long - period variables, so it seems that dy per stars do not constitute a separate group of variable stars.
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arxiv:0912.2097
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we propose a general theory of estimating interpolation error for smooth functions in two and three dimensions. in our theory, the error of interpolation is bound in terms of the diameter of a simplex and a geometric parameter. in the two - dimensional case, our geometric parameter is equivalent to the circumradius of a triangle. in the three - dimensional case, our geometric parameter also represents the flatness of a tetrahedron. through the introduction of the geometric parameter, the error estimates newly obtained can be applied to cases that violate the maximum - angle condition.
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arxiv:2002.09721
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we conduct a pebble - driven planet population synthesis study to investigate the formation of planets around very low - mass stars and brown dwarfs, in the ( sub ) stellar mass range between $ 0. 01 \ m _ { \ odot } $ and $ 0. 1 \ m _ { \ odot } $. based on the extrapolation of numerical simulations of planetesimal formation by the streaming instability, we obtain the characteristic mass of the planetesimals and the initial masses of the protoplanets ( largest bodies from the planetesimal size distributions ), in either the early self - gravitating phase or the later non - self - gravitating phase of the protoplanetary disk evolution. we find that the initial protoplanets form with masses that increase with host mass, orbital distance and decrease with disk age. around late m - dwarfs of $ 0. 1 \ m _ { \ odot } $, these protoplanets can grow up to earth - mass planets by pebble accretion. however, around brown dwarfs of $ 0. 01 \ m _ { \ odot } $, planets do not grow larger than mars mass when the initial protoplanets are born early in self - gravitating disks, and their growth stalls at around $ 0. 01 $ earth - mass when they are born late in non - self - gravitating disks. around these low mass stars and brown dwarfs, we find no channel for gas giant planet formation because the solid cores remain too small. when the initial protoplanets form only at the water - ice line, the final planets typically have $ { \ gtrsim } 15 \ % $ water mass fraction. alternatively, when the initial protoplanets form log - uniformly distributed over the entire protoplanetary disk, the final planets are either very water - rich ( water mass fraction $ { \ gtrsim } 15 \ % $ ) or entirely rocky ( water mass fraction $ { \ lesssim } 5 \ % $ ).
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arxiv:2004.07239
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we give sufficient conditions for the tautness of a transversely homogenous foliation defined on a compact manifold, by computing its base - like cohomology. as an application, we prove that if the foliation is non - unimodular then either the ambient manifold, the closure of the leaves or the total space of an associated principal bundle fiber over $ s ^ 1 $.
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arxiv:2005.07975
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magmatic volatiles can be considered as the surface fingerprint of active volcanic systems, both during periods of quiescent and eruptive volcanic activity. the spatial variability of gas emissions at earths surface is a proxy for structural discontinuities in the subsurface of volcanic systems. we conducted extensive and regular spaced soil gas surveys within the los humeros geothermal field to improve the understanding of the structural control on fluid flow. surveys at different scales were performed with the aim to identify areas of increased gas emissions on reservoir scale, their relation to unknown / knows volcano - tectonic structures on fault scale favoring fluid flow, and determine the origin of gas emissions. herein, we show results from a carbon dioxide efflux scouting survey, which was performed across the main geothermal production zone together with soil temperature measurements. we identified five areas with increased carbon dioxide emissions, where further sampling was performed with denser sampling grids to understand the fault zone architecture and local variations in gas emissions. we show that a systematic sampling approach on reservoir scale is necessary for the identification and assessment of major permeable fault segments. the combined processing of co2 efflux and carbon / helium isotopes facilitated the detection of permeable structural segments with a connection to the deep, high - temperature geothermal reservoir, also in areas with low to intermediate carbon dioxide emissions. the results of this study complement existing geophysical datasets and define further promising areas for future exploration activities in the north - and southwestern sector of the production field.
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arxiv:2002.11515
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we present an approach that uses a deep learning model, in particular, a multilayer perceptron ( mlp ), for estimating the missing values of a variable in multivariate time series data. we focus on filling a long continuous gap ( e. g., multiple months of missing daily observations ) rather than on individual randomly missing observations. our proposed gap filling algorithm uses an automated method for determining the optimal mlp model architecture, thus allowing for optimal prediction performance for the given time series. we tested our approach by filling gaps of various lengths ( three months to three years ) in three environmental datasets with different time series characteristics, namely daily groundwater levels, daily soil moisture, and hourly net ecosystem exchange. we compared the accuracy of the gap - filled values obtained with our approach to the widely - used r - based time series gap filling methods imputets and mtsdi. the results indicate that using an mlp for filling a large gap leads to better results, especially when the data behave nonlinearly. thus, our approach enables the use of datasets that have a large gap in one variable, which is common in many long - term environmental monitoring observations.
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arxiv:2202.12441
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pooling is an important component in convolutional neural networks ( cnns ) for aggregating features and reducing computational burden. compared with other components such as convolutional layers and fully connected layers which are completely learned from data, the pooling component is still handcrafted such as max pooling and average pooling. this paper proposes a learnable pooling function using recurrent neural networks ( rnn ) so that the pooling can be fully adapted to data and other components of the network, leading to an improved performance. such a network with learnable pooling function is referred to as a fully trainable network ( ftn ). experimental results have demonstrated that the proposed rnn - based pooling can well approximate the existing pooling functions and improve the performance of the network. especially for small networks, the proposed ftn can improve the performance by seven percentage points in terms of error rate on the cifar - 10 dataset compared with the traditional cnn.
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arxiv:1706.05157
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the anchor of most integral membrane proteins consists of one or several helices spanning the lipid bilayer. the walp peptide, gww ( la ) $ _ n $ ( l ) wwa, is a common model helix to study the fundamentals of protein insertion and folding, as well as helix - helix association in the membrane. its structural properties have been illuminated in a large number of experimental and simulation studies. in this combined coarse - grained and atomistic simulation study, we probe the thermodynamics of a single walp peptide, focusing on both the insertion across the water - membrane interface, as well as folding in both water and a membrane. the potential of mean force characterizing the peptide ' s insertion into the membrane shows qualitatively similar behavior across peptides and three force fields. however, the martini force field exhibits a pronounced secondary minimum for an adsorbed interfacial state, which may even become the global minimum - - - in contrast to both atomistic simulations and the alternative plum force field. even though the two coarse - grained models reproduce the free energy of insertion of individual amino acids side chains, they both underestimate its corresponding value for the full peptide ( as compared with atomistic simulations ), hinting at cooperative physics beyond the residue level. folding of walp in the two environments indicates the helix as the most stable structure, though with different relative stabilities and chain - length dependence.
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arxiv:1508.07280
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= = most reverse mathematics research focuses on subsystems of second - order arithmetic. the body of research in reverse mathematics has established that weak subsystems of second - order arithmetic suffice to formalize almost all undergraduate - level mathematics. in second - order arithmetic, all objects can be represented as either natural numbers or sets of natural numbers. for example, in order to prove theorems about real numbers, the real numbers can be represented as cauchy sequences of rational numbers, each of which sequence can be represented as a set of natural numbers. the axiom systems most often considered in reverse mathematics are defined using axiom schemes called comprehension schemes. such a scheme states that any set of natural numbers definable by a formula of a given complexity exists. in this context, the complexity of formulas is measured using the arithmetical hierarchy and analytical hierarchy. the reason that reverse mathematics is not carried out using set theory as a base system is that the language of set theory is too expressive. extremely complex sets of natural numbers can be defined by simple formulas in the language of set theory ( which can quantify over arbitrary sets ). in the context of second - order arithmetic, results such as post ' s theorem establish a close link between the complexity of a formula and the ( non ) computability of the set it defines. another effect of using second - order arithmetic is the need to restrict general mathematical theorems to forms that can be expressed within arithmetic. for example, second - order arithmetic can express the principle " every countable vector space has a basis " but it cannot express the principle " every vector space has a basis ". in practical terms, this means that theorems of algebra and combinatorics are restricted to countable structures, while theorems of analysis and topology are restricted to separable spaces. many principles that imply the axiom of choice in their general form ( such as " every vector space has a basis " ) become provable in weak subsystems of second - order arithmetic when they are restricted. for example, " every field has an algebraic closure " is not provable in zf set theory, but the restricted form " every countable field has an algebraic closure " is provable in rca0, the weakest system typically employed in reverse mathematics. = = = use of higher - order arithmetic = = = a recent strand of higher - order reverse mathematics research, initiated by ulrich kohlenbach in 2005, focuses on subsystems of higher - order arithmetic. due to the richer language of higher - order arithmetic, the
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https://en.wikipedia.org/wiki/Reverse_mathematics
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deconvolving ( " unfolding ' ' ) detector distortions is a critical step in the comparison of cross section measurements with theoretical predictions in particle and nuclear physics. however, most existing approaches require histogram binning while many theoretical predictions are at the level of statistical moments. we develop a new approach to directly unfold distribution moments as a function of another observable without having to first discretize the data. our moment unfolding technique uses machine learning and is inspired by generative adversarial networks ( gans ). we demonstrate the performance of this approach using jet substructure measurements in collider physics. with this illustrative example, we find that our moment unfolding protocol is more precise than bin - based approaches and is as or more precise than completely unbinned methods.
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arxiv:2407.11284
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the j \ " ulich - bonn group aims at an extensive study of the baryon - baryon ( $ bb $ ) interaction involving strange baryons ( $ \ lambda $, $ \ sigma $, $ \ xi $ ) within su ( 3 ) chiral effective field theory. an overview of achievements and new developments over the past few years is provided. the topics covered are : 1 ) derivation of the leading charge - symmetry breaking ( csb ) interaction for the $ \ lambda n $ system and its application in a study of csb effects in $ a $ = $ 4 $ $ \ lambda $ - hypernuclei. 2 ) updated results for the $ \ xi n $ interaction at nlo and predictions for $ \ xi ^ - p $ correlation functions. 3 ) extension of the $ \ lambda n $ - $ \ sigma n $ interaction to next - to - next - to - leading order.
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arxiv:2208.13542
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supernova ( sn ) classification and redshift estimation using photometric data only have become very important for the large synoptic survey telescope ( lsst ), given the large number of sne that lsst will observe and the impossibility of spectroscopically following up all the sne. we investigate the performance of a sn classifier that uses sn colors to classify lsst sne with the random forest classification algorithm. our classifier results in an auc of 0. 98 which represents excellent classification. we are able to obtain a photometric sn sample containing 99 $ \ % $ sne ia by choosing a probability threshold. we estimate the photometric redshifts ( photo - z ) of sne in our sample by fitting the sn light curves using the salt2 model with nested sampling. we obtain a mean bias ( $ \ left < z _ \ mathrm { phot } - z _ \ mathrm { spec } \ right > $ ) of 0. 012 with $ \ sigma \ left ( \ frac { z _ \ mathrm { phot } - z _ \ mathrm { spec } } { 1 + z _ \ mathrm { spec } } \ right ) = 0. 0294 $ without using a host - galaxy photo - z prior, and a mean bias ( $ \ left < z _ \ mathrm { phot } - z _ \ mathrm { spec } \ right > $ ) of 0. 0017 with $ \ sigma \ left ( \ frac { z _ \ mathrm { phot } - z _ \ mathrm { spec } } { 1 + z _ \ mathrm { spec } } \ right ) = 0. 0116 $ using a host - galaxy photo - z prior. assuming a flat $ \ lambda cdm $ model with $ \ omega _ m = 0. 3 $, we obtain $ \ omega _ m $ of $ 0. 305 \ pm0. 008 $ ( statistical errors only ), using the simulated lsst sample of photometric sne ia ( with intrinsic scatter $ \ sigma _ \ mathrm { int } = 0. 11 $ ) derived using our methodology without using host - galaxy photo - z prior. our method will help boost the power of sne from the lsst as cosmological probes.
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arxiv:1701.05689
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integer linear programs of configurations, or configuration ips, are a classical tool in the design of algorithms for scheduling and packing problems, where a set of items has to be placed in multiple target locations. herein a configuration describes a possible placement on one of the target locations, and the ip is used to chose suitable configurations covering the items. we give an augmented ip formulation, which we call the module configuration ip. it can be described within the framework of n - fold integer programming and therefore be solved efficiently. as an application, we consider scheduling problems with setup times, in which a set of jobs has to be scheduled on a set of identical machines, with the objective of minimizing the makespan. for instance, we investigate the case that jobs can be split and scheduled on multiple machines. however, before a part of a job can be processed an uninterrupted setup depending on the job has to be paid. for both of the variants that jobs can be executed in parallel or not, we obtain an efficient polynomial time approximation scheme ( eptas ) of running time $ f ( 1 / \ varepsilon ) \ times \ mathrm { poly } ( | i | ) $ with a single exponential term in $ f $ for the first and a double exponential one for the second case. previously, only constant factor approximations of $ 5 / 3 $ and $ 4 / 3 + \ varepsilon $ respectively were known. furthermore, we present an eptas for a problem where classes of ( non - splittable ) jobs are given, and a setup has to be paid for each class of jobs being executed on one machine.
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arxiv:1801.06460
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the geodesics prescription in holographic approach in lorentzian signature is valid only for geodesics which connect spacelike - separated points at the boundary, since there are no timelike geodesics which reach the boundary. there is also no straightforward analytic euclidean continuation for a general background, such as e. g. moving particle in ads. we propose an improved geodesic image method for two - point lorentzian correlators which is valid for arbitrary time intervals in case of the bulk spacetime deformed by point particles. we illustrate that our prescription is consistent with the case when the analytic continuation exists and with the quasigeodesics prescription used in previous work. we also discuss some other applications of the improved image method, such as holographic entanglement entropy and multiple particles in ads3.
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arxiv:1604.08905
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in this paper, we establish a partial order principle, which is useful to deriving vector ekeland variational principle ( denoted by evp ). by using the partial order principle and extending gerstewitz ' s functions, we obtain a vector evp for $ \ epsilon $ - efficient solutions in the sense of n \ ' { e } meth, which essentially improves the earlier results by removing a usual assumption for boundedness of range of the objective function. from this, we also deduce several special vector evps, which improve and generalize the related known results.
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arxiv:1611.03301
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decoherent transport in mesoscopic and nanoscopic systems can be formulated in terms of the d ' amato - pastawski ( dp ) model. this generalizes the landauer - b \ " { u } ttiker picture by considering a distribution of local decoherent processes. however, its generalization for multi - terminal setups is lacking. we first review the original two - terminal dp model for decoherent transport. then, we extend it to a matrix formulation capable of dealing with multi - terminal problems. we also introduce recursive algorithms to evaluate the green ' s functions for general banded hamiltonians as well as local density of states, effective conductances and voltage profiles. we finally illustrate the method by analyzing two problems of current relevance. 1 ) assessing the role of decoherence in a model for phonon lasers ( saser ). 2 ) obtaining the classical limit of giant magnetoresistance from a spin - dependent hamiltonian. the presented methods should pave the way for computationally demanding calculations of transport through nanodevices, bridging the gap between fully coherent quantum schemes and semiclassical ones.
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arxiv:1311.2231
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the dynamical phase diagram of interacting disordered systems has seen substantial revision over the past few years. theory must now account for a large prethermal many - body localized ( mbl ) regime in which thermalization is extremely slow, but not completely arrested. we derive a quantitative description of these dynamics in short - ranged one - dimensional systems using a model of successive many - body resonances. the model explains the decay timescale of mean autocorrelators, the functional form of the decay - a stretched exponential - and relates the value of the stretch exponent to the broad distribution of resonance timescales. the jacobi method of matrix diagonalization provides numerical access to this distribution, as well as a conceptual framework for our analysis. the resonance model correctly predicts the stretch exponents for several models in the literature. successive resonances may also underlie slow thermalization in strongly disordered systems in higher dimensions, or with long - range interactions.
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arxiv:2207.05761
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the electrostatic potential and energy of point charges in a real crystal, in the presence of thermal vibrations, is obtained as a special case of the fourier method. incorporating the role of thermal vibrations in electrostatic energy calculations leads to the physical meaning of the ewald sum method. the ewald summation method determines the electrostatic potential and energy of point charges in a crystal at a temperature that is obtained from the width of the gaussian and not at 0 k. for values of the width of the gaussian commonly recommended for computational convenience temperatures exceed 10000 k.
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arxiv:1104.1258
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we report precision mass measurements of $ ^ { 133 } $ sb, $ ^ { 133g, m } $ te, and $ ^ { 133g, m } $ i, produced at caribu at argonne national laboratory ' s atlas facility and measured using the canadian penning trap mass spectrometer. these masses clarify an anomaly in the $ ^ { 133 } $ te $ \ beta $ - decay. the masses reported in the 2020 atomic mass evaluation ( m. wang et al., 2021 ) produce $ q _ { \ beta ^ - } ( ^ { 133 } $ te ) = 2920 ( 6 ) kev ; however, the highest - lying $ ^ { 133 } $ i level populated in this decay is observed at $ e _ i = 2935. 83 ( 15 ) $ kev, resulting in an anomalous $ q _ { \ beta ^ { - } } ^ { i } = - 16 ( 6 ) $ ~ kev. our new measurements give $ q _ { \ beta ^ - } ( ^ { 133 } \ text { te } ) = 2934. 8 ( 11 ) $ kev, a factor of five more precise, yielding $ q { _ \ beta ^ i } = - 1. 0 ( 12 ) $ ~ kev, a 3 $ \ sigma $ shift from the previous results. this resolves this anomaly, but indicates further anomalies in our understanding of the structure of this isotope.
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arxiv:2312.06903
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the main objective of higher education is to provide quality education to students. one way to achieve highest level of quality in higher education system is by discovering knowledge for prediction regarding enrolment of students in a course. this paper presents a data mining project to generate predictive models for student retention management. given new records of incoming students, these predictive models can produce short accurate prediction lists identifying students who tend to need the support from the student retention program most. this paper examines the quality of the predictive models generated by the machine learning algorithms. the results show that some of the machines learning algorithms are able to establish effective predictive models from the existing student retention data.
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arxiv:1203.2987
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we find the local form of all non - closed lorentzian weyl manifolds $ ( m, c, \ nabla ) $ with recurrent curvature tensor. if the dimension of the manifold is greater than 3, then the conformal structure is flat, and the recurrent weyl structure is locally determined by a single function. two local structures are equivalent if and only if the corresponding functions are related by a transformation from $ \ mathrm { saff } _ 1 ( \ mathbb { r } ) \ times \ mathrm { psl } _ 2 ( \ mathbb { r } ) \ times \ mathbb { z } _ 2 $. we find generators for the field of rational scalar differential invariants of this lie group action. the global structure of the manifold $ m $ may be described in terms of a foliation with a transversal projective structure. it is shown that all locally homogeneous structures are locally equivalent, and there is only one simply connected homogeneous non - closed recurrent lorentzian weyl manifold. moreover, there are 5 classes of cohomogeneity - one spaces, and all other spaces are of cohomogeneity - two. if $ \ dim m = 3 $, the non - closed recurrent lorentzian weyl structures are locally determined by one function of two variables or two functions of one variables, depending on whether its holonomy algebra is 1 - or 2 - dimensional. in this case, two structures with the same holonomy algebra are locally equivalent if and only if they are related, respectively, by a transformation from an infinite - dimensional lie pseudogroup or a 4 - dimensional subgroup of $ \ mathrm { aff } ( \ mathbb r ^ 3 ) $. again we provide generators for the field of rational differential invariants. we find a local expression for the locally homogeneous non - closed recurrent lorentzian weyl manifolds of dimension 3, and also of those of cohomogeneity one and two. in the end we give a local description of the non - closed recurrent lorentzian weyl manifolds that are also einstein - weyl. all of them are 3 - dimensional and have a 2 - dimensional holonomy algebra.
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arxiv:2204.10163
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berge in [ 1 ] defined doubly primitive knots, which yield lens spaces by dehn surgery. at the same paper he listed the knots into several types. in this paper we will prove the list is complete when $ \ tau > 1 $. the invariant $ \ tau $ is a quantity with regard to lens space surgery, which is defined in this paper. furthermore at the same time we will also prove that table ~ 6 in [ 8 ] is complete as poincar \ ' e homology sphere surgery when $ \ tau > 1 $.
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arxiv:1005.3512
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the paper deals with the regularity criterion for the weak solutions to the 3d boussinesq equations in terms of the partial derivatives in besov spaces. it is proved that the weak solution $ ( u, \ theta ) $ becomes regular provided that $ ( \ nabla _ { h } u, \ nabla _ { h } \ theta ) \ in l ^ { \ frac { 8 } { 3 } } ( 0, t ; \ dot { b } _ { \ infty, \ infty } ^ { - 1 } ( \ mathbb { r } ^ { 3 } ) ) $ our results improve and extend the well - known results by fang - qian for the navier - stokes equations.
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arxiv:2005.04451
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the universality for the local spiked eigenvalues is a powerful tool to deal with the problems of the asymptotic law for the bulks of spiked eigenvalues of high - dimensional generalized fisher matrices. in this paper, we focus on a more generalized spiked fisher matrix, where $ \ sigma _ 1 \ sigma _ 2 ^ { - 1 } $ is free of the restriction of diagonal independence, and both of the spiked eigenvalues and the population 4th moments are not necessary required to be bounded. by reducing the matching four moments constraint to a tail probability, we propose a generalized four moment theorem ( g4mt ) for the bulks of spiked eigenvalues of high - dimensional generalized fisher matrices, which shows that the limiting distribution of the spiked eigenvalues of a generalized spiked fisher matrix is independent of the actual distributions of the samples provided to satisfy the our relaxed assumptions. furthermore, as an illustration, we also apply the g4mt to the central limit theorem for the spiked eigenvalues of generalized spiked fisher matrix, which removes the strict condition of the diagonal block independence given in wang and yao ( 2017 ) and extends their result to a wider usage without the requirements of the bounded 4th moments and the diagonal block independent structure, meeting the actual cases better.
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arxiv:1904.09236
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we propose and study the single - frame anisoplanatic deconvolution problem associated with image classification using machine learning algorithms, named the nonuniform defocus removal ( ndr ) problem. mathematical analysis of the ndr problem is done and the so - called defocus removal ( dr ) algorithm for solving it is proposed. global convergence of the dr algorithm is established without imposing any unverifiable assumption. numerical results on simulation data show significant features of dr including solvability, noise robustness, convergence, model insensitivity and computational efficiency. physical relevance of the ndr problem and practicability of the dr algorithm are tested on experimental data. back to the application that originally motivated the investigation of the ndr problem, we show that the dr algorithm can improve the accuracy of classifying distorted images using convolutional neural networks. the key difference of this paper compared to most existing works on single - frame anisoplanatic deconvolution is that the new method does not require the data image to be decomposable into isoplanatic subregions. therefore, solution approaches partitioning the image into isoplanatic zones are not applicable to the ndr problem and those handling the entire image such as the dr algorithm need to be developed and analyzed.
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arxiv:2106.13864
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a system obeying the harmonic oscillator equation of motion can be used as a force or proper acceleration sensor. in this short review we derive analytical expressions for the sensitivity of such sensors in a range of different situations, considering noise of thermal and measurement origins and a formalism for dealing with oscillators whose natural frequency $ \ omega _ 0 $ jitters. a special case where the sensitivity can be improved beyond the standard expressions and some applications with examples are also discussed.
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arxiv:1905.02612
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this paper describes problems in ai research and how the sp system ( described in an appendix ) may help to solve them. most of the problems are described by leading researchers in ai in interviews with science writer martin ford, and reported by him in his book { \ em architects of intelligence }. these problems are : the need to bridge the divide between symbolic and non - symbolic kinds of knowledge and processing ; the tendency of deep neural networks ( dnns ) to make large and unexpected errors in recognition ; the need to strengthen the representation and processing of natural languages ; the challenges of unsupervised learning ; the need for a coherent account of generalisation ; how to learn usable knowledge from a single exposure ; how to achieve transfer learning ; how to increase the efficiency of ai processing ; the need for transparency in ai structures and processes ; how to achieve varieties of probabilistic reasoning ; the need for more emphasis on top - down strategies ; how to minimise the risk of accidents with self - driving vehicles ; the need for strong compositionality in ai knowledge ; the challenges of commonsense reasoning and commonsense knowledge ; establishing the importance of information compression in ai research ; establishing the importance of a biological perspective in ai research ; establishing whether knowledge in the brain is represented in ` distributed ' or ` localist ' form ; how to bypassing the limited scope for adaptation in deep neural networks ; the need to develop ` broad ai ' ; and how to eliminate the problem of catastrophic forgetting.
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arxiv:2009.09079
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in this paper, the stability of the uniform solutions is analysed for microscopic flow models in interaction with $ k \ ge1 $ predecessors. we calculate general conditions for the linear stability on the ring geometry and explore the results with particular pedestrian and car - following models based on relaxation processes. the uniform solutions are stable if the relaxation times are sufficiently small. the analysis is focused on the relevance of the number of predecessors in the dynamics. unexpected non - monotonic relations between $ k $ and the stability are presented.
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arxiv:1701.06101
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we address the task of explaining relationships between two scientific documents using natural language text. this task requires modeling the complex content of long technical documents, deducing a relationship between these documents, and expressing the details of that relationship in text. in addition to the theoretical interest of this task, successful solutions can help improve researcher efficiency in search and review. in this paper we establish a dataset of 622k examples from 154k documents. we pretrain a large language model to serve as the foundation for autoregressive approaches to the task. we explore the impact of taking different views on the two documents, including the use of dense representations extracted with scientific ie systems. we provide extensive automatic and human evaluations which show the promise of such models, but make clear challenges for future work.
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arxiv:2002.00317
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we study semileptonic b decay to the exclusive charmless states pi, rho / omega, eta and eta ' using the 16 fb - 1 cleo upsilon ( 4s ) data sample. we find b ( b ^ 0 - > pi ^ - l ^ + nu ) = ( 1. 37 + - 0. 15 _ stat + - 0. 11 _ sys ) x 10 ^ - 4 and b ( b ^ 0 - > rho ^ - l ^ + nu ) = ( 2. 93 + - 0. 37 _ stat + - 0. 37 _ sys ) x 10 ^ - 4, and find evidence for b ^ + - > eta ' l ^ + nu, with b ( b ^ + - > eta ' l ^ + nu ) = ( 2. 66 + - 0. 80 _ stat + - 0. 56 _ sys ) x 10 ^ - 4. from our b - > pi l nu rate for q ^ 2 > 16 gev ^ 2 and lattice qcd we find | v _ { ub } | = ( 3. 6 + - 0. 4 _ stat + - 0. 2 _ syst + 0. 6 - 0. 4 _ thy ) x 10 ^ - 3.
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arxiv:hep-ex/0703041
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financial large language models ( finllms ) have been applied to various tasks in business, finance, accounting, and auditing. complex financial regulations and standards are critical to financial services, which llms must comply with. however, finllms ' performance in understanding and interpreting financial regulations has rarely been studied. therefore, we organize the regulations challenge, a shared task at coling 2025. it encourages the academic community to explore the strengths and limitations of popular llms. we create 9 novel tasks and corresponding question sets. in this paper, we provide an overview of these tasks and summarize participants ' approaches and results. we aim to raise awareness of finllms ' professional capability in financial regulations.
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arxiv:2412.11159
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in today ' s world, machine learning is hard to imagine without large training datasets and models. this has led to the use of stochastic methods for training, such as stochastic gradient descent ( sgd ). sgd provides weak theoretical guarantees of convergence, but there are modifications, such as stochastic variance reduced gradient ( svrg ) and stochastic recursive gradient algorithm ( sarah ), that can reduce the variance. these methods require the computation of the full gradient occasionally, which can be time consuming. in this paper, we explore variants of variance reduction algorithms that eliminate the need for full gradient computations. to make our approach memory - efficient and avoid full gradient computations, we use two key techniques : the shuffling heuristic and idea of sag / saga methods. as a result, we improve existing estimates for variance reduction algorithms without the full gradient computations. additionally, for the non - convex objective function, our estimate matches that of classic shuffling methods, while for the strongly convex one, it is an improvement. we conduct comprehensive theoretical analysis and provide extensive experimental results to validate the efficiency and practicality of our methods for large - scale machine learning problems.
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arxiv:2502.14648
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in this paper, we propose a scheme to implement the two - qubit controlled - z gate via the stark - tuned f \ " orster interaction of rydberg atoms, where the f \ " orster defect is driven by a time - dependent electric field of a simple sinusoidal function while the matrix elements of the dipole - dipole interaction are time - independent. it is shown that when the system is initially in a specific state, it makes a cyclic evolution after a preset interaction time, returning to the initial state, but picks up a phase, which can be used for realizing a two - atom controlled - z gate. due to the interference of sequential landau - zener transitions, the population and phase of the state is quasi - deterministic after the cyclic evolution and therefore the gate fidelity is insensitive to fluctuations of the interaction time and the dipole - dipole matrix elements. feasibility of the scheme realized with cs atoms is discussed in detail, which shows that the two - qubit gate via landau - zener control can be realized with the state - of - the - art experimental setup.
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arxiv:1806.09775
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nonequilibrium dynamics of highly - controlled quantum systems is a challenging issue in statistical physics and quantum many - body physics, relevant to recent experimental developments of analog and digital quantum simulations. in this work, we develop a discrete phase - space approach for general su ( $ n $ ) spin systems that utilizes cluster mean field equations, which capture non - trivial quantum correlations inside each cluster, beyond the capability of the standard discrete truncated wigner approximation for individual classical spins. our formalism, based on a cluster phase - point operator, enables efficient numerical samplings of cluster phase - space variables, where the total number of noise variables for a direct product state is independent of the specific way in which the entire system is divided into multiple equally sized finite clusters. we numerically demonstrate that the cluster discrete truncated wigner approximation ( c - dtwa ) method can reproduce key results in a recent experiment on correlation propagation dynamics in a two dimensional bose - hubbard system. we further compare the results of c - dtwa for clusters of $ 2 \ times 2 $ sites with those from a two - dimensional tensor network method and discuss that both approaches agree very well in the short - time region, where the energy conservation is well maintained in the tensor network simulations. since we formulate the c - dtwa method in a general form, it has the potential for application to various dynamical problems in isolated and open quantum systems, even in higher dimensions.
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arxiv:2404.18594
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sensor - based remote health monitoring is used in industrial, urban and healthcare settings to monitor ongoing operation of equipment and human health. an important aim is to intervene early if anomalous events or adverse health is detected. in the wild, these anomaly detection approaches are challenged by noise, label scarcity, high dimensionality, explainability and wide variability in operating environments. the contextual matrix profile ( cmp ) is a configurable 2 - dimensional version of the matrix profile ( mp ) that uses the distance matrix of all subsequences of a time series to discover patterns and anomalies. the cmp is shown to enhance the effectiveness of the mp and other sota methods at detecting, visualising and interpreting true anomalies in noisy real world data from different domains. it excels at zooming out and identifying temporal patterns at configurable time scales. however, the cmp does not address cross - sensor information, and cannot scale to high dimensional data. we propose a novel, self - supervised graph - based approach for temporal anomaly detection that works on context graphs generated from the cmp distance matrix. the learned graph embeddings encode the anomalous nature of a time context. in addition, we evaluate other graph outlier algorithms for the same task. given our pipeline is modular, graph construction, generation of graph embeddings, and pattern recognition logic can all be chosen based on the specific pattern detection application. we verified the effectiveness of graph - based anomaly detection and compared it with the cmp and 3 state - of - the art methods on two real - world healthcare datasets with different anomalies. our proposed method demonstrated better recall, alert rate and generalisability.
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arxiv:2211.16122
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question answering ( qa ) has been the subject of a resurgence over the past years. the said resurgence has led to a multitude of question answering ( qa ) systems being developed both by companies and research facilities. while a few components of qa systems get reused across implementations, most systems do not leverage the full potential of component reuse. hence, the development of qa systems is currently still a tedious and time - consuming process. we address the challenge of accelerating the creation of novel or tailored qa systems by presenting a concept for a self - wiring approach to composing qa systems. our approach will allow the reuse of existing, web - based qa systems or modules while developing new qa platforms. to this end, it will rely on qa modules being described using the web ontology language. based on these descriptions, our approach will be able to automatically compose qa systems using a data - driven approach automatically.
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arxiv:1611.01802
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double tunneling junctions of ferromagnet - superconductor - ferromagnet electrodes ( fsf ) show a jump in the conductance when a parallel magnetic field reverses the magnetization of one of the ferromagnetic electrodes. this change is generally attributed to the spin - valve effect or to pair breaking in the superconductor because of spin accumulation. in this paper it is shown that the meservey - tedrov effect causes a similar change in the conductance since the magnetic field changes the energy spectrum of the quasi - particles in the superconductor. a reversal of the bias reverses the sign in the conductance jump.
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arxiv:cond-mat/0410486
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the physics of flat band is novel and rich but difficult to access. in this regard, recently twisting of bilayer van der waals ( vdw ) - bounded two - dimensional ( 2d ) materials has attracted much attention, because the reduction of brillouin zone will eventually lead to a diminishing kinetic energy. alternatively, one may start with a 2d kagome lattice, which already possesses flat bands at the fermi level, but unfortunately these bands connect quadratically to other ( dispersive ) bands, leading to undesirable effects. here, we propose, by first - principles calculation and tight - binding modeling, that the same bilayer twisting approach can be used to isolate the kagome flat bands. as the starting kinetic energy is already vanishingly small, the interlayer vdw potential is always sufficiently large irrespective of the twisting angle. as such the electronic states in the ( connected ) flat bands become unstable against a spontaneous wigner crystallization, which is expected to have interesting interplays with other flat - band phenomena such as novel superconductivity and anomalous quantum hall effect.
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arxiv:2108.07641
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= =
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https://en.wikipedia.org/wiki/Pseudoscience
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the subgroups of gl ( n, r ) that act irreducibly on r ^ n and that can occur as the holonomy of a torsion - free affine connection on an n - manifold are classified, thus completing the work on this subject begun by m. berger in the 1950s. the methods employed include representation theory, the theory of hermitian symmetric spaces, twistor theory, and poisson geometry. the latter theory is especially important for the construction and classification of those torsion - free connections whose holonomy falls into one of the so - called ` exotic ' cases, i. e., those that were not included in berger ' s original lists. some remarks involving an interpretation of some of the examples in terms of supersymmetric constructions are also included.
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arxiv:math/9907206
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hyperatlas is an open standard intended to facilitate the large - scale federation of image - based data. the subject of hyperatlas is the space of sphere - to - plane projection mappings ( the fits - wcs information ), and the standard consists of coherent collections of these on which data can be resampled and thereby federated with other image data. we hope for a distributed effort that will produce a multi - faceted image atlas of the sky, made by federating many different surveys at different wavelengths and different times. we expect that hyperatlas - compliant imagery will be published and discovered through an international virtual observatory alliance ( ivoa ) registry, and that grid - based services will emerge for the required resampling and mosaicking.
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arxiv:astro-ph/0312195
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whether a quantum critical point ( qcp ) lies beneath the superconducting dome has been a long - standing issue that remains unresolved in many classes of unconventional superconductors, notably cuprates, heavy fermion compounds and most recently iron - pnictides. the existence of a qcp may offer a route to understand : the origin of their anomalous non - fermi liquid properties, the microscopic coexistence between unconventional superconductivity and magnetic or some exotic order, and ultimately the mechanism of superconductivity itself. the isovalent substituted iron - pnictide bafe $ _ 2 $ ( as $ _ { 1 - x } $ p $ _ x $ ) $ _ 2 $ offers a new platform for the study of quantum criticality, providing a unique opportunity to study the evolution of the electronic properties in a wide range of the phase diagram. recent experiments in bafe $ _ 2 $ ( as $ _ { 1 - x } $ p $ _ x $ ) $ _ 2 $ have provided the first clear and unambiguous evidence of a second order quantum phase transition lying beneath the superconducting dome.
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arxiv:1304.6387
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the presence of multiple populations in globular clusters has been well established thanks to high - resolution spectroscopy. it is widely accepted that distinct populations are a consequence of different stellar generations : intra - cluster pollution episodes are required to produce the peculiar chemistry observed in almost all clusters. unfortunately, the progenitors responsible have left an ambiguous signature and their nature remains unresolved. to constrain the candidate polluters, we have measured lithium and aluminium abundances in more than 180 giants across three systems : ngc ~ 1904, ngc ~ 2808, and ngc ~ 362. the present investigation along with our previous analysis of m12 and m5 affords us the largest database of simultaneous determinations of li and al abundances. our results indicate that li production has occurred in each of the three clusters. in ngc ~ 362 we detected an m12 - like behaviour, with first and second - generation stars sharing very similar li abundances favouring a progenitor that is able to produce li, such as agb stars. multiple progenitor types are possible in ngc ~ 1904 and ngc ~ 2808, as they possess both an intermediate population comparable in lithium to the first generation stars and also an extreme population, that is enriched in al but depleted in li. a simple dilution model fails in reproducing this complex pattern. finally, the internal li variation seems to suggest that the production efficiency of this element is a function of the cluster ' s mass and metallicity - low - mass or relatively metal - rich clusters are more adept at producing li.
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arxiv:1503.05925
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mathematical engineering ( or engineering mathematics ) is a branch of applied mathematics, concerning mathematical methods and techniques that are typically used in engineering and industry. along with fields like engineering physics and engineering geology, both of which may belong in the wider category engineering science, engineering mathematics is an interdisciplinary subject motivated by engineers ' needs both for practical, theoretical and other considerations outside their specialization, and to deal with constraints to be effective in their work. = = description = = historically, engineering mathematics consisted mostly of applied analysis, most notably : differential equations ; real and complex analysis ( including vector and tensor analysis ) ; approximation theory ( broadly construed, to include asymptotic, variational, and perturbative methods, representations, numerical analysis ) ; fourier analysis ; potential theory ; as well as linear algebra and applied probability, outside of analysis. these areas of mathematics were intimately tied to the development of newtonian physics, and the mathematical physics of that period. this history also left a legacy : until the early 20th century subjects such as classical mechanics were often taught in applied mathematics departments at american universities, and fluid mechanics may still be taught in ( applied ) mathematics as well as engineering departments. the success of modern numerical computer methods and software has led to the emergence of computational mathematics, computational science, and computational engineering ( the last two are sometimes lumped together and abbreviated as cs & e ), which occasionally use high - performance computing for the simulation of phenomena and the solution of problems in the sciences and engineering. these are often considered interdisciplinary fields, but are also of interest to engineering mathematics. specialized branches include engineering optimization and engineering statistics. engineering mathematics in tertiary education typically consists of mathematical methods and models courses. = = see also = = industrial mathematics control theory, a mathematical discipline concerned with engineering further mathematics and additional mathematics, a - level mathematics courses with similar content mathematical methods in electronics, signal processing and radio engineering = = references = =
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https://en.wikipedia.org/wiki/Engineering_mathematics
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the proton structure function f _ 2 ( x, q ^ 2 ) is measured in inelastic qed compton scattering using data collected with the h1 detector at hera. qed compton events are used to access the kinematic range of very low virtualities of the exchanged photon, q ^ 2, down to 0. 5 gev ^ 2, and bjorken x up to \ sim 0. 06, a region which has not been covered previously by inclusive measurements at hera. the results are in agreement with the measurements from fixed target lepton - nucleon scattering experiments.
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arxiv:hep-ex/0406029
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we use an exact solution of the relaxation - time boltzmann equation in a uniform ac electric field to describe the nonlinear optical response of graphene in the terahertz ( thz ). the cases of monolayer, bilayer and aba - stacked trilayer graphene are considered, and the monolayer species is shown to be the most appropriate one to exploit the nonlinear free electron response. we find that a single layer of monolayer graphene shows an optical bistability in the thz range, within the electromagnetic power range attainable in practice. the current associated with the third harmonic generation is also computed.
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arxiv:1406.5889
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the coherent transfer of excitations between different locations of a quantum many - body system is of primary importance in many research areas, from transport properties in spintronics and atomtronics to quantum state transfer in quantum information processing. we address the transfer of $ n > 1 $ bosonic and fermionic excitations between the edges of a one - dimensional chain modeled by a quadratic hopping hamiltonian, where the block edges, embodying the sender and the receiver sites, are weakly coupled to the quantum wire. we find that perturbatively perfect coherent transfer is attainable in the weak - coupling limit, for both bosons and fermions, only for certain modular arithmetic equivalence classes of the wire ' s length. finally we apply our findings to the transport of spins and the charging of a many - body quantum battery.
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arxiv:1911.12211
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purpose : to develop an automated algorithm allowing extraction of quantitative corneal transparency parameters from clinical spectral - domain oct images. to establish a representative dataset of normative transparency values from healthy corneas. methods : sd - oct images of 83 normal corneas ( ages 22 - 50 years ) from a standard clinical device ( rtvue - xr avanti, optovue inc. ) were processed. a pre - processing procedure is applied first, including a derivative approach and a pca - based correction mask, to eliminate common central artifacts ( i. e., apex - centered column saturation artifact and posterior stromal artifact ) and enable standardized analysis. the mean intensity stromal - depth profile is then extracted over a 6 - mm - wide corneal area and analyzed according to our previously developed method deriving quantitative transparency parameters related to the physics of light propagation in tissues, notably tissular heterogeneity ( birge ratio ; $ b _ r $ ), followed by the photon mean - free path ( $ l _ s $ ) in homogeneous tissues ( i. e., $ b _ r \ sim 1 $ ). results : after confirming stromal homogeneity ( $ b _ r < 10 $, idr : 1. 9 - 5. 1 ), we measured a median $ l _ s $ of 570 $ \ mu $ m ( idr : 270 - 2400 $ \ mu $ m ). considering corneal thicknesses, this may be translated into a median fraction of transmitted ( coherent ) light $ t _ { coh ( stroma ) } $ of 51 $ \ % $ ( idr : 22 - 83 $ \ % $ ). no statistically significant correlation between transparency and age or thickness was found. conclusions : our algorithm provides robust and quantitative measurement of corneal transparency from standard clinical sd - oct images. it yields lower transparency values than previously reported, which may be attributed to our method being exclusively sensitive to spatially coherent light. excluding images with central artifacts wider than 300 $ \ mu $ m also raises our median $ t _ { coh ( stroma ) } $ to 70 $ \ % $ ( idr : 34 - 87 $ \ % $ ).
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arxiv:2112.00528
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we compare the mean mass assembly histories of compact and fossil galaxy groups in the millennium dark matter simulation and an associated semi - analytic galaxy formation model. tracing the halo mass of compact groups ( cgs ) from z = 0 to z = 1 shows that, on average, 55 per cent of the halo mass in compact groups is assembled since z ~ 1, compared to 40 per cent of the halo mass in fossil groups ( fgs ) in the same time interval, indicating that compared to fgs, cgs are relatively younger galaxy systems. at z = 0, for a given halo mass, fossil groups tend to have a larger concentration than compact groups. investigating the evolution of cg ' s parameters show that they become more compact with time. cgs at z = 0. 5 see their magnitude gaps increase exponentially, but it takes ~ 10 gyr for them to reach a magnitude gap of 2 magnitudes. the slow growth of the magnitude gap leads to only a minority ( ~ 41 per cent ) of cgs selected at z = 0. 5 turning into a fg by z = 0. also, while three - quarters of fgs go through a compact phase, most fail to meet the cg isolation criterion, leaving only ~ 30 per cent of fgs fully satisfying the cg selection criteria. therefore, there is no strong link of cgs turning into fgs or fgs originating from cgs. the relation between cgs and fgs is thus more complex, and in most cases, fgs and cgs follow different evolutionary tracks.
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arxiv:1704.00731
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the history - dependent behaviors of classical plasticity models are often driven by internal variables evolved according to phenomenological laws. the difficulty to interpret how these internal variables represent a history of deformation, the lack of direct measurement of these internal variables for calibration and validation, and the weak physical underpinning of those phenomenological laws have long been criticized as barriers to creating realistic models. in this work, geometric machine learning on graph data ( e. g. finite element solutions ) is used as a means to establish a connection between nonlinear dimensional reduction techniques and plasticity models. geometric learning - based encoding on graphs allows the embedding of rich time - history data onto a low - dimensional euclidean space such that the evolution of plastic deformation can be predicted in the embedded feature space. a corresponding decoder can then convert these low - dimensional internal variables back into a weighted graph such that the dominating topological features of plastic deformation can be observed and analyzed.
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arxiv:2208.00246
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conversation designers continue to face significant obstacles when creating production quality task - oriented dialogue systems. the complexity and cost involved in schema development and data collection is often a major barrier for such designers, limiting their ability to create natural, user - friendly experiences. we frame the classification of user intent as the generation of a canonical form, a lightweight semantic representation using natural language. we show that canonical forms offer a promising alternative to traditional methods for intent classification. by tuning soft prompts for a frozen large language model, we show that canonical forms generalize very well to new, unseen domains in a zero - or few - shot setting. the method is also sample - efficient, reducing the complexity and effort of developing new task - oriented dialogue domains.
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arxiv:2211.05596
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we construct examples of variational bivectors that are not poissonian.
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arxiv:2505.03765
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the novatron magnetic mirror fusion reactor concept features significant advantages. these include stability against mhd interchange and kinetic dclc modes, axisymmetry, and minimized radial particle drifts and neoclassical losses. for achieving a ratio q > 30 of fusion power to heating power, axial particle confinement is uniquely designed to rely on the simultaneous use of three distinct forces ; magnetic mirrors, electrostatic potentials, and ponderomotive forces in a tandem - like configuration. axial confinement physics theory is here analyzed and compared to earlier mirror configurations. scenarios for d - t, d - d, and catalyzed d - d fusion plasmas are outlined.
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arxiv:2410.20134
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we study the cantor real base numeration system which is a common generalization of two positional systems, namely the cantor system with a sequence of integer bases and the r \ ' enyi system with one real base. we focus on the so - called alternate base $ b $ given by a purely periodic sequence of real numbers greater than 1. we answer an open question of charlier et al. on the set of numbers with eventually periodic $ b $ - expansions. we also investigate for which bases all sufficiently small rationals have a purely periodic $ b $ - expansion.
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arxiv:2402.01367
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given a graph with positive and negative edge labels, the correlation clustering problem aims to cluster the nodes so to minimize the total number of between - cluster positive and within - cluster negative edges. this problem has many applications in data mining, particularly in unsupervised learning. inspired by the prevalence of large graphs and constantly changing data in modern applications, we study correlation clustering in dynamic, parallel ( mpc ), and local computation ( lca ) settings. we design an approach that improves state - of - the - art runtime complexities in all these settings. in particular, we provide the first fully dynamic algorithm that runs in an expected amortized constant time, without any dependence on the graph size. moreover, our algorithm essentially matches the approximation guarantee of the celebrated pivot algorithm.
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arxiv:2402.15668
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we analyze the bianchi ix universe in the polymer quantum mechanics framework by facing both semiclassical and purely quantum effects near the cosmological singularity. we adopt misner variables to describe the model dynamics, applying the polymer paradigm simultaneously to the isotropic one ( linked to the universe volume ) and to the two anisotropy ones ( characterizing the physical gravitational degrees of freedom ). setting two different cut - off scales for the two different variable sets, i. e. the geometrical volume and the gravity tensor modes, we demonstrate how the semiclassical properties of the bianchi ix dynamics are sensitive to the ratio of the cut - off parameters. in particular, the semiclassical evolution turns out to be chaotic only if the parameter associated to the volume discretization is greater or equal to that one of the anisotropies. concerning the chaotic case we perform a purely quantum polymer analysis, demonstrating that the original misner result about the existence of quasi - classical states near the singularity ( in the sense of high occupation numbers ) is still valid in the revised approach and able to account for cut - off physics effects. the possibility for a comparison with the original study by misner is possible because the singularity is still present in the semiclassical evolution of the cosmological model for all the parameter space. we interpret this surprising feature as the consequence of a geometrical volume discretization which does not prevent the volume from vanishing, i. e. restoring in the minisuperspace analysis its zero value.
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arxiv:1907.12083
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no true extrasolar earth analog is known. hundreds of planets have been found around sun - like stars that are either earth - sized but on shorter periods, or else on year - long orbits but somewhat larger. under strong assumptions, exoplanet catalogs have been used to make an extrapolated estimate of the rate at which sun - like stars host earth analogs. these studies are complicated by the fact that every catalog is censored by non - trivial selection effects and detection efficiencies, and every property ( period, radius, etc. ) is measured noisily. here we present a general hierarchical probabilistic framework for making justified inferences about the population of exoplanets, taking into account survey completeness and, for the first time, observational uncertainties. we are able to make fewer assumptions about the distribution than previous studies ; we only require that the occurrence rate density be a smooth function of period and radius ( employing a gaussian process ). by applying our method to synthetic catalogs, we demonstrate that it produces more accurate estimates of the whole population than standard procedures based on weighting by inverse detection efficiency. we apply the method to an existing catalog of small planet candidates around g dwarf stars ( petigura et al. 2013 ). we confirm a previous result that the radius distribution changes slope near earth ' s radius. we find that the rate density of earth analogs is about 0. 02 ( per star per natural logarithmic bin in period and radius ) with large uncertainty. this number is much smaller than previous estimates made with the same data but stronger assumptions.
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arxiv:1406.3020
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it is well known that the addition of noise in a multistable system can induce random transitions between stable states. the rate of transition can be characterised in terms of the noise - free system ' s dynamics and the added noise : for potential systems in the presence of asymptotically low noise the well - known kramers ' escape time gives an expression for the mean escape time. this paper examines some general properties and examples of transitions between local steady and oscillatory attractors within networks : the transition rates at each node may be affected by the dynamics at other nodes. we use first passage time theory to explain some properties of scalings noted in the literature for an idealised model of initiation of epileptic seizures in small systems of coupled bistable systems with both steady and oscillatory attractors. we focus on the case of sequential escapes where a steady attractor is only marginally stable but all nodes start in this state. as the nodes escape to the oscillatory regime, we assume that the transitions back are very infrequent in comparison. we quantify and characterise the resulting sequences of noise - induced escapes. for weak enough coupling we show that a master equation approach gives a good quantitative understanding of sequential escapes, but for strong coupling this description breaks down.
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arxiv:1705.08462
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aims : we investigate a new method to for obtaining the plasma parameters of solar prominences observed in the mgii h & k spectral lines by comparing line profiles from the iris satellite to a bank of profiles computed with a one - dimensional non - local thermodynamic equilibrium ( non - lte ) radiative transfer code. methods : using a grid of 1007 one - dimensional non - lte radiative transfer models we carry out this new method to match computed spectra to observed line profiles while accounting for line core shifts not present in the models. the prominence observations were carried out by the iris satellite on 19 april 2018. results : the prominence is very dynamic with many flows. the models are able to recover satisfactory matches in areas of the prominence where single line profiles are observed. we recover : mean temperatures of 6000 to 50, 000k ; mean pressures of 0. 01 to 0. 5 dyne cm $ ^ { - 2 } $ ; column masses of 3. 7 $ \ times10 ^ { - 8 } $ to 5 $ \ times10 ^ { - 4 } $ g cm $ ^ { - 2 } $ ; a mean electron density of 7. 3 $ \ times10 ^ { 8 } $ to 1. 8 $ \ times10 ^ { 11 } $ cm $ ^ { - 3 } $ ; and an ionisation degree $ { n _ \ text { hii } } / { n _ \ text { hi } } = 0. 03 - 4500 $. the highest values for the ionisation degree are found in areas where the line of sight crosses mostly plasma from the pctr, correlating with high mean temperatures and correspondingly no h $ \ alpha $ emission. conclusions : this new method naturally returns information on how closely the observed and computed profiles match, allowing the user to identify areas where no satisfactory match between models and observations can be obtained. regions where satisfactory fits were found were more likely to contain a model encompassing a pctr. the line core shift can also be recovered from this new method, and it shows a good qualitative match with that of the line core shift found by the quantile method. this demonstrates the effectiveness of the approach to line core shifts in the new method.
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arxiv:2106.10351
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the dueling bandits problem is an online learning framework for learning from pairwise preference feedback, and is particularly well - suited for modeling settings that elicit subjective or implicit human feedback. in this paper, we study the problem of multi - dueling bandits with dependent arms, which extends the original dueling bandits setting by simultaneously dueling multiple arms as well as modeling dependencies between arms. these extensions capture key characteristics found in many real - world applications, and allow for the opportunity to develop significantly more efficient algorithms than were possible in the original setting. we propose the \ selfsparring algorithm, which reduces the multi - dueling bandits problem to a conventional bandit setting that can be solved using a stochastic bandit algorithm such as thompson sampling, and can naturally model dependencies using a gaussian process prior. we present a no - regret analysis for multi - dueling setting, and demonstrate the effectiveness of our algorithm empirically on a wide range of simulation settings.
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arxiv:1705.00253
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we prove an averaging principle which asserts convergence of diffusion processes on domains separated by semi - permeable membranes, when diffusion coefficients tend to infinity while the flux through the membranes remains constant. in the limit, points in each domain are lumped into a single state of a limit markov chain. the limit chain ' s intensities are proportional to the membranes ' permeability and inversely proportional to the domains ' sizes. analytically, the limit is an example of a singular perturbation in which boundary and transmission conditions play a crucial role. this averaging principle is strongly motivated by recent signaling pathways models of mathematical biology, which are discussed towards the end of the paper.
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arxiv:1603.00494
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we consider random fields indexed by finite subsets of an amenable discrete group, taking values in the banach - space of bounded right - continuous functions. the field is assumed to be equivariant, local, coordinate - wise monotone, and almost additive, with finite range dependence. using the theory of quasi - tilings we prove an uniform ergodic theorem, more precisely, that averages along a foelner sequence converge uniformly to a limiting function. moreover we give explicit error estimates for the approximation in the sup norm.
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arxiv:1711.07525
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let $ y _ 1 $ be a closed, oriented 3 - manifold and $ \ sigma $ denote a non - separating closed, orientable surface in $ y _ 1 $ which consists of two connected components of the same genus. by cutting $ y _ 1 $ along $ \ sigma $ and re - gluing it using an orientation - preserving diffeomorphism of $ \ sigma $ we obtain another closed, oriented 3 - manifold $ y _ 2 $. when the excision surface $ \ sigma $ is of genus one, we show that twisted heegaard floer homology groups of $ y _ 1 $ and $ y _ 2 $ ( twisted with coefficients in the universal novikov ring ) are isomorphic. we use this excision theorem to demonstrate that certain manifolds are not related by the excision construction on a genus one surface. additionally, we apply the excision formula to compute twisted heegaard floer homology groups of 0 - surgery on certain two - component links, including some families of 2 - bridge links.
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arxiv:2410.20307
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we give an explicit dimension formula for paramodular forms of degree two of prime level with plus or minus sign of the atkin - - lehner involution of weight $ \ det ^ k \ operatorname { sym } ( j ) $ with $ k \ geq 3 $, as well as a dimension formula for algebraic modular forms of any weight associated with the binary quaternion hermitian maximal lattices in non - principal genus of prime discriminant with fixed sign of the involution. these two formulas are essentially equivalent by a recent result of n. dummigan, a. pacetti. g. rama and g. tornar \ ' ia on correspondence between algebraic modular forms and paramodular forms with signs. so we give the formula by calculating the latter. when $ p $ is odd, our formula for the latter is based on a class number formula of some quinary lattices by t. asai and its interpretation to the type number of quaternion hermitian forms given in our previous works. on paramodular forms, we also give a dimensional bias between plus and minus eigenspaces, some list of palindromic hilbert series, numerical examples for small $ p $ and $ k $, and the complete list of primes $ p $ such that there is no paramodular cusp form of level $ p $ of weight 3 with plus sign. this last result has geometric meaning on moduli of kummer surface with $ ( 1, p ) $ polarization.
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arxiv:2208.13578
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twitter is now a gold marketing tool for entities concerned with online reputation. to automatically monitor online reputation of entities, systems have to deal with ambiguous entity names, polarity detection and topic detection. we propose three approaches to tackle the first issue : monitoring twitter in order to find relevant tweets about a given entity. evaluated within the framework of the replab - 2013 filtering task, each of them has been shown competitive with state - of - the - art approaches. mainly we investigate on how much merging strategies may impact performances on a filtering task according to the evaluation measure.
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arxiv:1510.07385
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the quantum behavior of superconducting qubits coupled to resonators is very similar to that of atoms in optical cavities [ 1, 2 ], in which the resonant cavity confines photons and promotes strong light - matter interactions. the cavity end - mirrors determine the performance of the coupled system, with higher mirror reflectivity yielding better quantum coherence, but higher mirror transparency giving improved measurement and control, forcing a compromise. an alternative is to control the mirror transparency, enabling switching between long photon lifetime during quantum interactions and large signal strength when performing measurements. here we demonstrate the superconducting analogue, using a quantum system comprising a resonator and a qubit, with variable coupling to a measurement transmission line. the coupling can be adjusted through zero to a photon emission rate 1, 000 times the intrinsic photon decay rate. we use this system to control photons in coherent states as well as in non - classical fock states, and dynamically shape the waveform of released photons. this has direct applications to circuit quantum electrodynamics [ 3 ], and may enable high - fidelity quantum state transfer between distant qubits, for which precisely - controlled waveform shaping is a critical and non - trivial requirement [ 4, 5 ].
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arxiv:1208.2950
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