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we analyze the $ \ eta n $ interaction using a coupled channel separable potential model that implements the chiral symmetry. the model predicts an $ \ eta n $ stattering length $ \ re a _ { \ eta n } \ approx 0. 7 $ fm and in - medium subthreshold attraction most likely sufficient to generate $ \ eta $ - nuclear bound states. the energy dependence of the $ \ eta n $ amplitude and pole content of the model are discussed. an idea of the same origin of the baryon resonances $ n ^ { \ star } ( 1535 ) $ and $ n ^ { \ star } ( 1650 ) $ is presented. | arxiv:1308.4300 |
in this article, some properties of complex wiener - it \ ^ o multiple integrals and complex ornstein - uhlenbeck operators and semigroups are obtained. those include stroock ' s formula, hu - meyer formula, clark - ocone formula and the hypercontractivity of complex ornstein - uhlenbeck semigroups. as an application, several expansions of the fourth moments of complex wiener - it \ ^ o multiple integrals are given. | arxiv:1902.09111 |
the two underlying requirements of face age progression, i. e. aging accuracy and identity permanence, are not well studied in the literature. in this paper, we present a novel generative adversarial network based approach. it separately models the constraints for the intrinsic subject - specific characteristics and the age - specific facial changes with respect to the elapsed time, ensuring that the generated faces present desired aging effects while simultaneously keeping personalized properties stable. further, to generate more lifelike facial details, high - level age - specific features conveyed by the synthesized face are estimated by a pyramidal adversarial discriminator at multiple scales, which simulates the aging effects in a finer manner. the proposed method is applicable to diverse face samples in the presence of variations in pose, expression, makeup, etc., and remarkably vivid aging effects are achieved. both visual fidelity and quantitative evaluations show that the approach advances the state - of - the - art. | arxiv:1711.10352 |
in scenarios where electrons are confined to a flat surface, such as graphene, quantizing electrodynamics reveals intriguing insights. we find that one of maxwell ' s equations manifests as part of the hamiltonian, leading to novel constraints on physical states due to residual gauge invariance. we identify two quantum states with zero energy expectation values : one replicates the scattering and absorption of light, a phenomenon familiar in classical optics, while the other is more fundamentally associated with photon creation. these states form an inseparable two - state system, giving a new formula for reflection and transmission coefficients with photon emission effects. notably, there exists a special thickness of the surface where these states decouple, offering intriguing possibilities for exploring physics through symmetry - based perturbations involving concepts of parity, axial gauge fields, and surface deformation. | arxiv:2303.08395 |
we consider self - avoiding polymers attached to the tip of an impenetrable probe. the scaling exponents $ \ gamma _ 1 $ and $ \ gamma _ 2 $, characterizing the number of configurations for the attachment of the polymer by one end, or at its midpoint, vary continuously with the tip ' s angle. these apex exponents are calculated analytically by $ \ epsilon $ - expansion, and numerically by simulations in three dimensions. we find that when the polymer can move through the attachment point, it typically slides to one end ; the apex exponents quantify the entropic barrier to threading the eye of the probe. | arxiv:cond-mat/0409055 |
we investigate the luminosity evolution of the host galaxies of radio - loud agn through hubble space telescope imaging of 72 bl lac objects, including new stis imaging of nine z > 0. 6 bl lacs. with their intrinsically low accretion rates and their strongly beamed jets, bl lacs provide a unique opportunity to probe host galaxy evolution independent of the biases and ambiguities implicit in quasar studies. we find that the host galaxies of bl lacs evolve strongly, consistent with passive evolution from a period of active star formation in the range 0. 5 < ~ z < ~ 2. 5, and inconsistent with either passive evolution from a high formation redshift or a non - evolving population. this evolution is broadly consistent with that observed in the hosts of other radio - loud agn, and inconsistent with the flatter luminosity evolution of quiescent early types and radio - quiet hosts. this indicates that active star formation, and hence galaxy interactions, are associated with the formation for radio - loud agn, and that these host galaxies preferentially accrete less material after their formation epoch than galaxies without powerful radio jets. we discuss possible explanations for the link between merger history and the incidence of a radio jet. | arxiv:astro-ph/0411099 |
we consider a non - newtonian incompressible heat conducting fluid with prescribed nonuniform temperature on the boundary and with the no - slip boundary conditions for the velocity. we assume no external body forces. for the power - law like models with the power law index bigger than $ 11 / 5 $ in three dimensions, we identify a class of solutions fulfilling the entropy equality and converging to the equilibria exponentially in a proper metric. in fact, we show the existence of a lyapunov functional for the problem. consequently, the steady solution is nonlinearly stable and attracts all suitable weak solutions. | arxiv:2210.10878 |
in previous works, we proposed to estimate cosmological parameters with the artificial neural network ( ann ) and the mixture density network ( mdn ). in this work, we propose an improved method called the mixture neural network ( mnn ) to achieve parameter estimation by combining ann and mdn, which can overcome shortcomings of the ann and mdn methods. besides, we propose sampling parameters in a hyper - ellipsoid for the generation of the training set, which makes the parameter estimation more efficient. a high - fidelity posterior distribution can be obtained using $ \ mathcal { o } ( 10 ^ 2 ) $ forward simulation samples. in addition, we develop a code - named colfi for parameter estimation, which incorporates the advantages of mnn, ann, and mdn, and is suitable for any parameter estimation of complicated models in a wide range of scientific fields. colfi provides a more efficient way for parameter estimation, especially for cases where the likelihood function is intractable or cosmological models are complex and resource - consuming. it can learn the conditional probability density $ p ( \ boldsymbol \ theta | \ boldsymbol { d } ) $ using samples generated by models, and the posterior distribution $ p ( \ boldsymbol \ theta | \ boldsymbol { d } _ 0 ) $ can be obtained for a given observational data $ \ boldsymbol { d } _ 0 $. we tested the mnn using power spectra of the cosmic microwave background and type ia supernovae and obtained almost the same result as the markov chain monte carlo method. the numerical difference only exists at the level of $ \ mathcal { o } ( 10 ^ { - 2 } \ sigma ) $. the method can be extended to higher - dimensional data. | arxiv:2306.11102 |
assuming $ d ^ * _ { sj } ( 2317 ) $ and $ d _ { sj } ( 2460 ) $ to be the $ ( 0 ^ +, 1 ^ + ) $ chiral partners of regular $ d _ { s } ( 1968 ) $ and $ d ^ { * } _ { s } ( 2112 ) $, we calculate the semileptonic decays of $ b _ s $ to $ d _ s ( 1968 ) $, $ d ^ * _ s ( 2112 ) $, $ d _ { sj } ^ { * } ( 2317 ) $, $ d _ { sj } ( 2460 ) $ in terms of the constituent quark meson ( cqm ) model. the large branching ratios of the semileptonic decays of $ b _ s $ to $ d _ { sj } ^ { * } ( 2317 ) $ and $ d _ { sj } ( 2460 ) $ indicate that those two semileptonic decays should be seen in future experiments. | arxiv:hep-ph/0612008 |
cite [ chap ii, \ s12, theorem 12. 1 ] { ursul } are not true, then we corrected this result in the right way. | arxiv:2303.02634 |
the motivation for the development of a local finite density theory is discussed. one of the problems related to an instability in the baryon number fluctuation of the chiral symmetry breaking phase of the quark system in the local theory is shown to exist. such an instability problem is removed by taking into account the statistical blocking effects for the quark propagator, which depends on a macroscopic { \ em statistical blocking parameter } $ \ epsilon $. this new frame work is then applied to study color superconducting phase of the light quark system. | arxiv:hep-ph/0001184 |
within the context of a chern - simons running - vacuum - model ( rvm ) cosmology, one expects an early - matter dominated ( emd ) reheating period after rvm inflation driven by the axion field. treating thus in this work chern - simons rvm cosmology as an effective $ f ( r ) $ gravity theory characterized by logarithmic corrections of the spacetime curvature, we study the gravitational - wave ( gw ) signal induced by the nearly - scale invariant inflationary adiabatic curvature perturbations during the transition from the emd era driven by the axion to the late radiation - dominated era. remarkably, by accounting for the extra gw scalaron polarization present within $ f ( r ) $ gravity theories, we find regions in the parameter space of the theory where one is met with a distinctive induced gw signal with a universal $ f ^ 6 $ high - frequency scaling compared to the $ f ^ 7 $ scaling present in general relativity ( gr ). interestingly enough, for axion masses $ m _ a $ higher than 1 gev and axion gauge couplings $ f _ a $ above $ 10 ^ { - 3 } $ planck mass, one can produce induced gw spectra within the sensitivity bands of future gw observatories such as the einstein telescope ( et ), the laser interferometer space antenna ( lisa ), the big bang observer ( bbo ) and the square kilometer arrays ( ska ). | arxiv:2411.14223 |
this paper presents a novel control strategy to herd a group of non - cooperative evaders by means of a team of robotic herders. in herding problems, the motion of the evaders is typically determined by strong nonlinear reactive dynamics, escaping from the herders. many applications demand the herding of numerous and / or heterogeneous entities, making the development of flexible control solutions challenging. in this context, our main contribution is a control approach that finds suitable herding actions even when the nonlinearities in the evaders ' dynamics yield to implicit equations. we resort to numerical analysis theory to characterise the existence conditions of such actions and propose two design methods to compute them, one transforming the continuous time implicit system into an expanded explicit system, and the other applying a numerical method to find the action in discrete time. simulations and real experiments validate the proposal in different scenarios. | arxiv:2010.10895 |
we extend the seminal model of pathak and s \ " onmez ( 2008 ) to a setting with multiple school districts, each running its own separate centralized match, and focus on the case of two districts. in our setting, in addition to each student being either sincere or sophisticated, she is also either constrained - able to apply only to schools within her own district of residence - or unconstrained - able to choose any single district within which to apply. we show that several key results from pathak and s \ " onmez ( 2008 ) qualitatively flip : a sophisticated student may prefer for a sincere student to become sophisticated, and a sophisticated student may prefer for her own district to use deferred acceptance over the boston mechanism, irrespective of the mechanism used by the other district. we furthermore investigate the preferences of students over the constraint levels of other students. many of these phenomena appear abundantly in large random markets. | arxiv:2403.04530 |
the main aim of this paper is to study existence and stability properties of rotationally symmetric proper biharmonic maps between two $ m $ - dimensional models ( in the sense of greene and wu ). we obtain a complete classification of rotationally symmetric, proper biharmonic conformal diffeomorphisms in the special case that $ m = 4 $ and the models have constant sectional curvature. then, by introducing the hamiltonian associated to this problem, we also obtain a complete description of conformal proper biharmonic solutions in the case that the domain model is $ { \ mathbb r } ^ 4 $. in the second part of the paper we carry out a stability study with respect to equivariant variations ( equivariant stability ). in particular, we prove that : ( i ) the inverse of the stereographic projection from the open $ 4 $ - dimensional euclidean ball to the hyperbolic space is equivariant stable ; ( ii ) the inverse of the stereographic projection from the closed $ 4 $ - dimensional euclidean ball to the sphere is equivariant stable with respect to variations which preserve the boundary data. | arxiv:1501.04576 |
), safe 2 ), effective and 3 ), applicable to all the manufactured devices. a product is safe if patients, users, and third parties do not run unacceptable risks of physical hazards, such as injury or death, in its intended use. protective measures must be introduced on devices that are hazardous to reduce residual risks at an acceptable level if compared with the benefit derived from the use of it. a product is effective if it performs as specified by the manufacturer in the intended use. proof of effectiveness is achieved through clinical evaluation, compliance to performance standards or demonstrations of substantial equivalence with an already marketed device. the previous features have to be ensured for all the manufactured items of the medical device. this requires that a quality system shall be in place for all the relevant entities and processes that may impact safety and effectiveness over the whole medical device lifecycle. the medical device engineering area is among the most heavily regulated fields of engineering, and practicing biomedical engineers must routinely consult and cooperate with regulatory law attorneys and other experts. the food and drug administration ( fda ) is the principal healthcare regulatory authority in the united states, having jurisdiction over medical devices, drugs, biologics, and combination products. the paramount objectives driving policy decisions by the fda are safety and effectiveness of healthcare products that have to be assured through a quality system in place as specified under 21 cfr 829 regulation. in addition, because biomedical engineers often develop devices and technologies for " consumer " use, such as physical therapy devices ( which are also " medical " devices ), these may also be governed in some respects by the consumer product safety commission. the greatest hurdles tend to be 510k " clearance " ( typically for class 2 devices ) or pre - market " approval " ( typically for drugs and class 3 devices ). in the european context, safety effectiveness and quality is ensured through the " conformity assessment " which is defined as " the method by which a manufacturer demonstrates that its device complies with the requirements of the european medical device directive ". the directive specifies different procedures according to the class of the device ranging from the simple declaration of conformity ( annex vii ) for class i devices to ec verification ( annex iv ), production quality assurance ( annex v ), product quality assurance ( annex vi ) and full quality assurance ( annex ii ). the medical device directive specifies detailed procedures for certification. in general terms, these procedures include tests and verifications that are to be contained in specific deliveries such as the risk management file, the technical file, and the quality system deliveries. the risk management file | https://en.wikipedia.org/wiki/Biomedical_engineering |
this review aims to provide a simple introduction to the application of optical correlation methods in colloidal science. in particular, i plan to show that full appraisal of the intimate relation between light scattering and microscopy allows designing novel powerful investigation techniques that combine their powers. an extended version of this paper will appear in " colloidalfoundations of nanoscience ", edited by d. berti and g. palazzo, elsevier ( isbn 978 - 0 - 444 - 59541 - 6 ). i am very grateful to the publisher for having granted me the permission to post this preprint on arxiv. | arxiv:1306.1401 |
we introduce vemoclap : video emotion classifier using pretrained features, the first readily available and open - source web application that analyzes the emotional content of any user - provided video. we improve our previous work, which exploits open - source pretrained models that work on video frames and audio, and then efficiently fuse the resulting pretrained features using multi - head cross - attention. our approach increases the state - of - the - art classification accuracy on the ekman - 6 video emotion dataset by 4. 3 % and offers an online application for users to run our model on their own videos or youtube videos. we invite the readers to try our application at serkansulun. com / app. | arxiv:2410.21303 |
we prove functional inequalities in any dimension controlling the iterated derivatives along a transport of the coulomb or super - coulomb riesz modulated energy in terms of the modulated energy itself. this modulated energy was introduced by the second author and collaborators in the study of mean - field limits and statistical mechanics of coulomb / riesz gases, where control of such derivatives by the energy itself is an essential ingredient. in this paper, we extend and improve such functional inequalities, proving estimates which are now sharp in their additive error term, in their density dependence, valid at arbitrary order of differentiation, and localizable to the support of the transport. our method relies on the observation that these iterated derivatives are the quadratic form of a commutator. taking advantage of the riesz nature of the interaction, we identify these commutators as solutions to a degenerate elliptic equation with a right - hand side exhibiting a recursive structure in terms of lower - order commutators and develop a local regularity theory for the commutators, which may be of independent interest. these estimates have applications to obtaining sharp rates of convergence for mean - field limits, quasi - neutral limits, and in proving central limit theorems for the fluctuations of coulomb / riesz gases. in particular, we show here the expected $ n ^ { \ frac { \ mathsf { s } } { \ mathsf { d } } - 1 } $ - rate in the modulated energy distance for the mean - field convergence of first - order hamiltonian and gradient flows. | arxiv:2407.15650 |
we present vespa, an intentionally simple yet novel zero - shot system for layout, locale, and domain agnostic document extraction. in spite of the availability of large corpora of documents, the lack of labeled and validated datasets makes it a challenge to discriminatively train document extraction models for enterprises. we show that this problem can be addressed by simply transferring the information extraction ( ie ) task to a natural language question - answering ( qa ) task without engineering task - specific architectures. we demonstrate the effectiveness of our system by evaluating on a closed corpus of real - world retail and tax invoices with multiple complex layouts, domains, and geographies. the empirical evaluation shows that our system outperforms 4 prominent commercial invoice solutions that use discriminatively trained models with architectures specifically crafted for invoice extraction. we extracted 6 fields with zero upfront human annotation or training with an avg. f1 of 87. 50. | arxiv:2108.06069 |
in this contribution some aspects of supergravity and super yang - mills systems in d = 6 are briefly reviewed and, in some cases, are contrasted with the analogous features in d = 4. particular emphasis is laid on the stringy solutions of the d = 6 super yang - mills systems. | arxiv:hep-th/9809044 |
in this paper, we compute the slice genus for many low - crossing virtual knots. for instance, we show that 1295 out of 92800 virtual knots with 6 or fewer crossings are slice, and that all but 248 of the rest are not slice. key to these results are computations of turaev ' s graded genus, which we show extends to give an invariant of virtual knot concordance. the graded genus is remarkably effective as a slice obstruction, and we develop an algorithm that applies virtual unknotting operations to determine the slice genus of many virtual knots with 6 or fewer crossings. | arxiv:1708.05982 |
this paper presents a novel framework for state - of - charge estimation of rechargeable batteries in electric vehicles using a two - stage nonlinear estimator called the exogenous kalman filter ( xkf ). the nonlinear estimator consists of a cascade of nonlinear observer ( nlo ) and linearized kalman filter ( lkf ). the nlo is used to produce a globally convergent auxiliary state estimate that is used to generate a linearized model in the time - varying kalman filter algorithm. to demonstrate the proposed approach, we present a model of a lithium - ion battery from an equivalent circuit model ( ecm ). the model has linear process equations and a nonlinear output voltage equation. the method is tested using experimental data of a lithium iron phosphate ( lifepo $ _ 4 $ ) battery under dynamic stress test ( dst ) and federal urban driving schedule ( fuds ). effect on different ambient temperatures is also discussed. compared with ekf and ukf, our proposed xkf achieve faster convergence rate, which can be attributed to the use of the nlo. | arxiv:1810.09014 |
websites have become increasingly important in people ' s lives, fulfilling a wide range of needs across various domains such as shopping, education, news, and booking. among the most heavily used website categories are online shopping platforms, whose usage has particularly increased during the covid - 19 pandemic, as they eliminate time and geographical barriers, providing access to a broader customer base. for these websites to effectively meet user needs and deliver a positive experience, they must be well - designed and adhere to usability principles. however, some existing shopping websites are poorly designed and do not follow usability best practices, resulting in suboptimal user experiences. traditional manual website evaluation methods are time - consuming, and there is a need for more intelligent, automated approaches, particularly those leveraging machine learning techniques. this study aims to assist fashion shopping website developers in improving the usability of their platforms by providing an intelligent approach that can evaluate website usability. the study employs two complementary approaches for the evaluation process. the first model utilizes a support vector machine ( svm ) to assess websites based on specific usability principles, while the second model is a convolutional neural network ( cnn ) that evaluates websites using features extracted from their screenshot images. the datasets for this project were custom - built, comprising a textual dataset for the svm model and a screenshot dataset for the cnn model. the results demonstrate that the svm model achieved an impressive 99 % accuracy, while the cnn model attained 69 % accuracy. these findings highlight the potential of this intelligent approach to provide comprehensive, data - driven insights for improving the usability of fashion shopping websites. | arxiv:2411.12770 |
the summarization of conversation, that is, discourse over discourse, elevates pragmatic considerations as a pervasive limitation of both summarization and other applications of contemporary conversational ai. building on impressive progress in both semantics and syntax, pragmatics concerns meaning in the practical sense. in this paper, we discuss several challenges in both summarization of conversations and other conversational ai applications, drawing on relevant theoretical work. we illustrate the importance of pragmatics with so - called star sentences, syntactically acceptable propositions that are pragmatically inappropriate in conversation or its summary. because the baseline for quality of ai is indistinguishability from human behavior, we draw heavily on the psycho - linguistics literature, and label our complaints as " turing test triggers " ( ttts ). we discuss implications for the design and evaluation of conversation summarization methods and conversational ai applications like voice assistants and chatbots | arxiv:2304.14543 |
the origin of the anomalous, 400 % increase of the piezoelectric coefficient in sc $ _ x $ al $ _ { 1 - x } $ n alloys is revealed. quantum mechanical calculations show that the effect is intrinsic. it comes from a strong change in the response of the internal atomic coordinates to strain and pronounced softening of c $ _ { 33 } $ elastic constant. the underlying mechanism is the flattening of the energy landscape due to a competition between the parent wurtzite and the so far experimentally unknown hexagonal phases of the alloy. our observation provides a route for the design of materials with high piezoelectric response. | arxiv:1003.3353 |
in this paper we study the variational method and integral equation methods for a conical diffraction problem for imperfectly conducting gratings modeled by the impedance boundary value problem of the helmholtz equation in periodic structures. we justify the strong ellipticity of the sesquilinear form corresponding to the variational formulation and prove the uniqueness of solutions at any frequency. convergence of the finite element method using the transparent boundary condition ( dirichlet - to - neumann mapping ) is verified. the boundary integral equation method is also discussed. | arxiv:2304.04434 |
the amateur sky survey ( tass ) is a loose confederation of amateur and professional astronomers. we describe the design and construction of our mark iv systems, a set of wide - field telescopes with ccd cameras which take simultaneous images in the $ v $ and $ i _ c $ passbands. we explain our observational procedures and the pipeline which processes and reduces the images into lists of stellar positions and magnitudes. we have compiled a large database of measurements for stars in the northern celestial hemisphere with $ v $ - band magnitudes in the range 7 < v < 13. this paper describes data taken over the four - year period starting november, 2001. one of our results is a catalog of repeated measurements on the johnson - cousins system for over 4. 3 million stars. | arxiv:astro-ph/0610529 |
we present a comprehensive investigation into disorder - mediated charge transport in inp nanowires in the statistical doping regime. at zero gate voltage transport is well described by the space charge limited current model and efros - shklovskii variable range hopping, but positive gate voltage ( electron accumulation ) reveals a previously unexplored regime of nanowire charge transport that is not well described by existing theory. the ability to continuously tune between these regimes provides guidance for the extension of existing models and directly informs the design of next - generation nanoscale electronic devices. | arxiv:1106.4492 |
we give $ q $ - analogues of the following two ramanujan - type formulas for $ 1 / \ pi $ : \ begin { align * } \ sum _ { k = 0 } ^ \ infty ( 6k + 1 ) \ frac { ( \ frac { 1 } { 2 } ) _ k ^ 3 } { k! ^ 3 4 ^ k } = \ frac { 4 } { \ pi } \ quad \ text { and } \ quad \ sum _ { k = 0 } ^ \ infty ( - 1 ) ^ k ( 6k + 1 ) \ frac { ( \ frac { 1 } { 2 } ) _ k ^ 3 } { k! ^ 3 8 ^ k } = \ frac { 2 \ sqrt { 2 } } { \ pi }. \ end { align * } our proof is based on two $ q $ - wz pairs found by the first author in his earlier work. | arxiv:1802.01944 |
investigating the reasoning abilities of transformer models, and discovering new challenging tasks for them, has been a topic of much interest. recent studies have found these models to be surprisingly strong at performing deductive reasoning over formal logical theories expressed in natural language. a shortcoming of these studies, however, is that they do not take into account that logical theories, when sampled uniformly at random, do not necessarily lead to hard instances. we propose a new methodology for creating challenging algorithmic reasoning datasets that focus on natural language satisfiability ( nlsat ) problems. the key idea is to draw insights from empirical sampling of hard propositional sat problems and from complexity - theoretic studies of language. this methodology allows us to distinguish easy from hard instances, and to systematically increase the complexity of existing reasoning benchmarks such as ruletaker. we find that current transformers, given sufficient training data, are surprisingly robust at solving the resulting nlsat problems of substantially increased difficulty. they also exhibit some degree of scale - invariance - the ability to generalize to problems of larger size and scope. our results, however, reveal important limitations too : a careful sampling of training data is crucial for building models that generalize to larger problems, and transformer models ' limited scale - invariance suggests they are far from learning robust deductive reasoning algorithms. | arxiv:2112.09054 |
thanks to hubble and chandra telescopes, some of the large scale jets in extragalactic radio sources are now being observed at optical and x - ray frequencies. for the fr i objects the synchrotron nature of this emission is surely established, although a lot of uncertainties - connected for example with the particle acceleration processes involved - remain. in this paper we study production of high energy gamma - rays in fr i kiloparsec - scale jets by inverse - compton emission of the synchrotron - emitting electrons. we consider different origin of seed photons contributing to the inverse - compton scattering, including nuclear jet radiation as well as ambient, stellar and circumstellar emission of the host galaxies. we discuss how future detections or non - detections of the evaluated gamma - ray fluxes can provide constraints on the unknown large scale jet parameters, i. e. the magnetic field intensity and the jet doppler factor. for the nearby sources centaurus a and m 87, we find measurable fluxes of tev photons resulting from synchrotron self - compton process and from comptonisation of the galactic photon fields, respectively. in the case of centaurus a, we also find a relatively strong emission component due to comptonisation of the nuclear blazar photons, which could be easily observed by glast at energy ~ 10 gev, providing important test for the unification of fr i sources with bl lac objects. | arxiv:astro-ph/0306251 |
a permutation $ \ pi $ of a multiset is said to be a { \ em quasi - stirling } permutation if there does not exist four indices $ i < j < k < \ ell $ such that $ \ pi _ i = \ pi _ k $ and $ \ pi _ j = \ pi _ { \ ell } $. define $ $ \ overline { q } _ { \ mathcal { m } } ( t, u, v ) = \ sum _ { \ pi \ in \ overline { \ mathcal { q } } _ { \ mathcal { m } } } t ^ { des ( \ pi ) } u ^ { asc ( \ pi ) } v ^ { plat ( \ pi ) }, $ $ where $ \ overline { \ mathcal { q } } _ { \ mathcal { m } } $ denotes the set of quasi - stirling permutations on the multiset $ \ mathcal { m } $, and $ asc ( \ pi ) $ ( resp. $ des ( \ pi ) $, $ plat ( \ pi ) $ ) denotes the number of ascents ( resp. descents, plateaux ) of $ \ pi $. denote by $ \ mathcal { m } ^ { \ sigma } $ the multiset $ \ { 1 ^ { \ sigma _ 1 }, 2 ^ { \ sigma _ 2 }, \ ldots, n ^ { \ sigma _ n } \ } $, where $ \ sigma = ( \ sigma _ 1, \ sigma _ 2, \ ldots, \ sigma _ n ) $ is an $ n $ - composition of $ k $ for positive integers $ k $ and $ n $. in this paper, we show that $ \ overline { q } _ { \ mathcal { m } ^ { \ sigma } } ( t, u, v ) = \ overline { q } _ { \ mathcal { m } ^ { \ tau } } ( t, u, v ) $ for any two $ n $ - compositions $ \ sigma $ and $ \ tau $ of $ k $. this is accomplished by establishing an $ ( asc, des, plat ) $ - preserving bijection between $ \ overline { \ mathcal { q } } _ { \ mathcal { m } ^ { \ sigma } } $ and $ \ overline { \ mathcal { q } } | arxiv:2106.04348 |
whereas their photophysics exhibits an intricate interplay of carriers with the lattice, most reports have so far relied on single compound studies. with the exception of variations of the organic spacer cations, the effect of constituent substitution on the photophysics and the nature of emitting species, in particular, has remained largely under - explored. here pea $ _ 2 $ pbbr $ _ 4 $, pea $ _ 2 $ pbi $ _ 4 $, and pea $ _ 2 $ sni $ _ 4 $ are studied through a variety of optical spectroscopy techniques to reveal a complex set of excitonic transitions at low temperature. we attribute the emergence of weak high energy features to a vibronic progression breaking kasha ' s rule and highlight that the responsible phonons cannot be accessed through simple raman spectroscopy. bright peaks at lower energy are due to two distinct excitons, of which the upper is a convolution of a bright exciton and a localised state, whereas the lower is attributed to shallow defects. our study offers deeper insights into the photophysics of two - dimensional perovskites through compositional substitution and highlights critical limits to the communities ' current understanding of the photophysics of these compounds. | arxiv:2104.10393 |
linear codes with a few weights are very important in coding theory and have attracted a lot of attention. in this paper, we present a construction of $ q $ - ary linear codes from trace and norm functions over finite fields. the weight distributions of the linear codes are determined in some cases based on gauss sums. it is interesting that our construction can produce optimal or almost optimal codes. furthermore, we show that our codes can be used to construct secret sharing schemes with interesting access structures and strongly regular graphs with new parameters. | arxiv:1605.04063 |
we propose a scheme to implement the phase - robust topological router based on a one - dimensional dimerized superconducting circuit lattice with long - range hopping. we show that the proposed dimerized superconducting circuit lattice can be mapped into an extended chiral - symmetric su - schrieffer - heeger ( ssh ) model with long - range hopping, in which the existence of long - range hopping induces a special zero - energy mode. the peculiar distribution of the zero - energy mode enables us to engineer a phase - robust topological router, which can achieve quantum state transfer ( qst ) from one site ( input port ) to multiple sites ( output ports ). benefiting from the topological protection of chiral symmetry, we demonstrate that the presence of the mild disorder in nearest - neighbor and long - range hopping has no appreciable effects on qst in the lattice. especially, after introducing another new long - range hopping into the extended ssh lattice, we propose an optimized protocol of the phase - robust topological router, in which the number of the output ports can be efficiently increased. resorting to the bose statistical properties of the superconducting circuit lattice, the input port and output ports assisted by the zero - energy mode can be detected via the mean distribution of the photons. our work breaks the traditional qst form with only one outport by the zero - energy mode and opens a pathway to construct large - scale quantum information processing in the ssh chains with long - range hopping. | arxiv:2206.07285 |
we introduce a new approach to a century old assumption which enhances not only planetary interior calculations but also high pressure material physics. we show that the polytropic index is the derivative of the bulk modulus with respect to pressure. we then augment the traditional polytrope theory by including a variable polytrope index within the confines of the lane - emden differential equation. to investigate the possibilities of this method we create a high quality universal equation of state, transforming the traditional polytrope method to a tool with the potential for excellent predictive power. the theoretical foundation of our equation of state is the same elastic observable which we found equivalent to the polytrope index, the derivative of the bulk modulus with respect to pressure. we calculate the density - pressure of six common materials up to 10 $ ^ { 18 } $ pa, mass - radius relationships for the same materials, and produce plausible density - radius models for the rocky planets of our solar system. we argue that the bulk modulus and its derivatives have been under utilized in previous planet formation methods. we constrain the material surface observables for the inner core, outer core, and mantle of planet earth in a systematic way including pressure, bulk modulus, and the polytrope index in the analysis. we believe this variable polytrope method has the necessary apparatus to be extended further to gas giants and stars. as supplemental material we provide computer code to calculate multi - layered planets. | arxiv:1409.5525 |
we propose a new method for the calculation of error rates in automatic speech recognition ( asr ). this new metric is for languages that contain half characters and where the same character can be written in different forms. we implement our methodology in hindi which is one of the main languages from indic context and we think this approach is scalable to other similar languages containing a large character set. we call our metrics alternate word error rate ( awer ) and alternate character error rate ( acer ). we train our asr models using wav2vec 2. 0 \ cite { baevski2020wav2vec } for indic languages. additionally we use language models to improve our model performance. our results show a significant improvement in analyzing the error rates at word and character level and the interpretability of the asr system is improved upto $ 3 $ \ % in awer and $ 7 $ \ % in acer for hindi. our experiments suggest that in languages which have complex pronunciation, there are multiple ways of writing words without changing their meaning. in such cases awer and acer will be more useful rather than wer and cer as metrics. further, we open source a new benchmarking dataset of 21 hours for hindi with the new metric scripts. | arxiv:2203.16601 |
ly $ \ alpha $ $ \ lambda $ 1216 ( ly $ \ alpha $ ) emission extending over $ \ gtrsim \, \ rm 10 \, kiloparsec \, ( kpc ) $ around dusty, massive starbursts at $ z \ gtrsim3 $ might represent a short - lived phase in the evolution of present - day, massive quiescent galaxies. to obtain empirical constraints on this emerging scenario, we present ly $ \ alpha $, civ $ \ lambda $ 1550 ( civ ), and heii $ \ lambda $ 1640 ( heii ) observations taken with the multi unit spectroscopic explorer towards j1000 $ + $ 0234 : a galaxy pair at $ z = 4. 5 $ composed of a low - mass starburst ( j1000 $ + $ 0234 $ - $ south ) neighboring a massive submillimeter galaxy ( smg ; j1000 $ + $ 0234 $ - $ north ) that harbors a rotationally supported gas disk. based on the spatial distribution and relative strength of ly $ \ alpha $, civ, and heii, we find that star formation in j1000 + 0234 $ - $ south and an active galactic nucleus in j1000 + 0234 $ - $ north are dominant factors in driving the observed 40 kiloparsec - scale ly $ \ alpha $ blob ( lab ). we use the non - resonant heii line to infer kinematic information of the lab. we find marginal evidence for two spatially and spectrally separated heii regions, which suggests that the two - peaked ly $ \ alpha $ profile is mainly a result of two overlapping and likely interacting hi clouds. we also report the serendipitous identification of three ly $ \ alpha $ emitters spanning over a redshift bin $ \ delta z \ leq 0. 007 $ ( i. e., $ \ lesssim 380 \, \ rm km \, s ^ { - 1 } $ ) located at $ \ lesssim 140 \, \ rm kpc $ from j1000 + 0234. a galaxy overdensity analysis confirms that j1000 + 0234 lies near the center of a megaparsec - scale galaxy overdensity at $ z = 4. 5 $ that might evolve into a galaxy cluster at $ z = 0 $. the properties of j1000 + 02 | arxiv:2210.07982 |
low - energy electronic states in heterosrtuctures formed by ultranarrow layer ( single or several monolayers thickness ) are studied theoretically. the host material is described within the effective mass approximation and effect of ultranarrow layers is taken into account within the framework of the transfer matrix approach. using the current conservation requirement and the inversion symmetry of ultranarrow layer, the transfer matrix is written through two phenomenological parameters. the binding energy of localized state, the reflection ( transmission ) coefficient for the single ultranarrow layer case, and the energy spectrum of superlattice are determined by these parameters. spectral dependency of absorption in superlattice due to photoexcitation of electrons from localized states into minibands is strongly dependent on the ultranarrow layers characteristics. such a dependency can be used for verification of the transfer matrix parameters. | arxiv:1110.0744 |
the modular transformations of the $ ( 1 | 1 ) $ complex supermanifolds in the like - schottky modular parameterization are discussed. it is shown that these " supermodular " transformations depend on the spinor structure of the supermanifold by terms proportional to the odd modular parameters. the above terms are calculated in the explicit form. they are urgent for the divergency problem in the ramond - neveu - schwarz superstring theory and for calculating the fundamental domain in the modular space. the supermodular transformations of the multi - loop superstring partition functions calculated by the solution of the ward identities are studied. the above ward identities are shown to be covariant under the supermodular transformations. so the partition functions necessarily possess the covariance under the transformations discussed. it is demonstrated explicitly the covariance of the above partition functions at zero odd moduli under those supermodular transformations, which turn a pair of even genus - 1 spinor structures to a pair of the odd genus - 1 spinor ones. the brief consideration of the cancellation of divergences is given. | arxiv:hep-th/9512057 |
the role of the uncertainty principle is examined through the examples of squeezing, information capacity, and position monitoring. it is suggested that more attention should be directed to conceptual considerations in quantum information science and technology. | arxiv:quant-ph/0510069 |
robotic manipulation behavior should be robust to disturbances that violate high - level task - structure. such robustness can be achieved by constantly monitoring the environment to observe the discrete high - level state of the task. this is possible because different phases of a task are characterized by different sensor patterns and by monitoring these patterns a robot can decide which controllers to execute in the moment. this relaxes assumptions about the temporal sequence of those controllers and makes behavior robust to unforeseen disturbances. we implement this idea as probabilistic filter over discrete states where each state is direcly associated with a controller. based on this framework we present a robotic system that is able to open a drawer and grasp tennis balls from it in a surprisingly robust way. | arxiv:2205.04172 |
we directly measure the thermal energy of the gas surrounding galaxies through the thermal sunyaev - zel ' dovich ( tsz ) effect. we perform a stacking analysis of microwave background images from the atacama cosmology telescope, around 1179 massive quiescent elliptical galaxies at 0. 5 < = z < = 1. 0 ( ' low - z ' ) and 3274 galaxies at 1. 0 < = z < = 1. 5 ( ' high - z ' ), selected using data from the wide - field infrared survey explorer all - sky survey and the sloan digital sky survey ( sdss ) within the sdss stripe - 82 field. the gas surrounding these galaxies is expected to contain energy from past episodes of active galactic nucleus ( agn ) feedback, and after using modeling to subtract undetected contaminants, we detect a tsz signal at a significance of 0. 9 - sigma for our low - z galaxies and 1. 8 - sigma for our high - z galaxies. we then include data from the high - frequency planck bands for a subset of 227 low - z galaxies and 529 high - z galaxies and find low - z and high - z tsz detections of 1. 0 - sigma and 1. 5 - sigma, respectively. these results indicate an average thermal heating around these galaxies of 5. 6 ( + 5. 9 / - 5. 6 ) x 10 ^ 60 erg for our low - z galaxies and 7. 0 ( + 4. 7 / - 4. 4 ) x 10 ^ 60 erg for our high - z galaxies. based on simple heating models, these results are consistent with gravitational heating without additional heating due to agn feedback. | arxiv:1610.02068 |
we study the problem of learning granger causality between event types from asynchronous, interdependent, multi - type event sequences. existing work suffers from either limited model flexibility or poor model explainability and thus fails to uncover granger causality across a wide variety of event sequences with diverse event interdependency. to address these weaknesses, we propose cause ( causality from attributions on sequence of events ), a novel framework for the studied task. the key idea of cause is to first implicitly capture the underlying event interdependency by fitting a neural point process, and then extract from the process a granger causality statistic using an axiomatic attribution method. across multiple datasets riddled with diverse event interdependency, we demonstrate that cause achieves superior performance on correctly inferring the inter - type granger causality over a range of state - of - the - art methods. | arxiv:2002.07906 |
numerical integration over the real line for analytic functions is studied. our main focus is on the sharpness of the error bounds. we first derive two general lower estimates for the worst - case integration error, and then apply these to establish lower bounds for various quadrature rules. these bounds turn out to be either novel or improve upon existing results, leading to lower bounds that closely match upper bounds for various formulas. specifically, for the suitably truncated trapezoidal rule, we improve upon general lower bounds on the worst - case error obtained by sugihara [ \ textit { numer. math. }, 75 ( 1997 ), pp. ~ 379 - - 395 ] and provide exceptionally sharp lower bounds apart from a polynomial factor, and in particular show that the worst - case error for the trapezoidal rule by sugihara is not improvable by more than a polynomial factor. additionally, our research reveals a discrepancy between the error decay of the trapezoidal rule and sugihara ' s lower bound for general numerical integration rules, introducing a new open problem. moreover, gauss - - hermite quadrature is proven sub - optimal under the decay conditions on integrands we consider, a result not deducible from upper - bound arguments alone. furthermore, to establish the near - optimality of the suitably scaled gauss - - legendre and clenshaw - - curtis quadratures, we generalize a recent result of trefethen [ \ textit { siam rev. }, 64 ( 2022 ), pp. ~ 132 - - 150 ] for the upper error bounds in terms of the decay conditions. | arxiv:2401.07196 |
\ in \ widehat { \ mathbb { z } } $ and $ \ lim _ { n \ to \ infty } \ underline { c } _ n \ to 0 $. | arxiv:1511.03465 |
monte carlo simulations of protein folding show the emergence of a strong correlation between the relative contact order parameter, co, and the folding time, t, of two - state folding proteins for longer chains with number of amino acids, n > = 54, and higher contact order, co > 0. 17. the correlation is particularly strong for n = 80 corresponding to slow and more complex folding kinetics. these results are qualitatively compatible with experimental data where a general trend towards increasing t with co is indeed observed in a set of proteins with chain length ranging from 41 to 154 amino acids. | arxiv:cond-mat/0205631 |
crowdsourcing has emerged as a popular approach for collecting annotated data to train supervised machine learning models. however, annotator bias can lead to defective annotations. though there are a few works investigating individual annotator bias, the group effects in annotators are largely overlooked. in this work, we reveal that annotators within the same demographic group tend to show consistent group bias in annotation tasks and thus we conduct an initial study on annotator group bias. we first empirically verify the existence of annotator group bias in various real - world crowdsourcing datasets. then, we develop a novel probabilistic graphical framework groupanno to capture annotator group bias with a new extended expectation maximization ( em ) training algorithm. we conduct experiments on both synthetic and real - world datasets. experimental results demonstrate the effectiveness of our model in modeling annotator group bias in label aggregation and model learning over competitive baselines. | arxiv:2110.08038 |
we investigate possible list extensions of generalised majority edge colourings of graphs and provide several results concerning these. given a graph $ g = ( v, e ) $, a list assignment $ l : e \ to 2 ^ c $ and some level of majority tolerance $ \ alpha \ in ( 0, 1 ) $, an $ \ alpha $ - majority $ l $ - colouring of $ g $ is a colouring $ \ omega : e \ to c $ from the given lists such that for every $ v \ in v $ and each $ c \ in c $, the number of edges coloured $ c $ which are incident with $ v $ does not exceed $ \ alpha \ cdot d ( v ) $. we present a simple argument implying that for every integer $ k \ geq 2 $, each graph with minimum degree $ \ delta \ geq 2k ^ 2 - 2k $ admits a $ 1 / k $ - majority $ l $ - colouring from any assignment of lists of size $ k + 1 $. this almost matches the best result in a non - list setting and solves a conjecture posed for the basic majority edge colourings, i. e. for $ k = 2 $, from lists. we further discuss restrictions which permit obtaining corresponding results in a more general setting, i. e. for diversified $ \ alpha = \ alpha ( c ) $ majority tolerances for distinct colours $ c \ in c $. consider a list assignment $ l : e \ to 2 ^ c $ with $ \ sum _ { c \ in l ( e ) } \ alpha ( c ) \ geq 1 + \ varepsilon $ for each edge $ e $, and suppose that $ \ alpha ( c ) \ geq a $ for every $ c $ or $ | l ( e ) | \ leq \ ell $ for all edges $ e $, where $ a \ in ( 0, 1 ) $, $ \ varepsilon > 0 $, $ \ ell \ in \ mathbb { n } $ are any given constants. then we in particular show that there exists an $ \ alpha $ - majority $ l $ - colouring of $ g $ from any such list assignment, provided that $ \ delta ( g ) = \ omega ( a ^ { - 1 } \ varepsilon ^ { - 2 } \ ln ( a \ varepsilon ) ^ { - 1 } ) $ or $ \ delta = | arxiv:2502.12688 |
we present the calculation of the nlo qcd corrections to the electroweak production of top - antitop pairs at the cern lhc in the presence of a new neutral gauge boson. the corrections are implemented in the parton shower monte carlo program powheg. standard model ( sm ) and new physics interference effects are properly taken into account. qed singularities, first appearing at this order, are consistently subtracted. numerical results are presented for sm and $ z ' $ total cross sections and distributions in invariant mass, transverse momentum, azimuthal angle and rapidity of the top - quark pair. the remaining theoretical uncertainty from scale and pdf variations is estimated, and the potential of the charge asymmetry to distinguish between new physics models is investigated for the sequential sm and a leptophobic topcolor model. | arxiv:1511.08185 |
let $ g $ be a simple finite graph. a famous theorem of dirac says that $ g $ is chordal if and only if $ g $ admits a perfect elimination order. it is known by fr \ " oberg that the edge ideal $ i ( g ) $ of $ g $ has a linear resolution if and only if the complementary graph $ g ^ c $ of $ g $ is chordal. in this article, we discuss some algebraic consequences of dirac ' s theorem in the theory of homological shift ideals of edge ideals. recall that if $ i $ is a monomial ideal, $ \ mbox { hs } _ k ( i ) $ is the monomial ideal generated by the $ k $ th multigraded shifts of $ i $. we prove that $ \ mbox { hs } _ 1 ( i ) $ has linear quotients, for any monomial ideal $ i $ with linear quotients generated in a single degree. for and edge ideal $ i ( g ) $ with linear quotients, it is not true that $ \ mbox { hs } _ k ( i ( g ) ) $ has linear quotients for all $ k \ ge0 $. on the other hand, if $ g ^ c $ is a proper interval graph or a forest, we prove that this is the case. finally, we discuss a conjecture of bandari, bayati and herzog that predicts that if $ i $ is polymatroidal, $ \ mbox { hs } _ k ( i ) $ is polymatroidal too, for all $ k \ ge0 $. we are able to prove that this conjecture holds for all polymatroidal ideals generated in degree two. | arxiv:2212.00395 |
the classical 1991 result by brightwell and winkler states that the number of linear extensions of a poset is # p - complete. we extend this result to posets with certain restrictions. first, we prove that the number of linear extension for posets of height two is # p - complete. furthermore, we prove that this holds for incidence posets of graphs. finally, we prove that the number of linear extensions for posets of dimension two is # p - complete. | arxiv:1802.06312 |
a reduced - order model based on proper orthogonal decomposition ( pod ) is proposed for the bidomain equations of cardiac electrophysiology. its accuracy is assessed through electrocardiograms in various configurations, including myocardium infarctions and long - time simulations. we show in particular that a restitution curve can efficiently be approximated by this approach. the reduced - order model is then used in an inverse problem solved by an evolutionary algorithm. some attempts are presented to identify ionic parameters and infarction locations from synthetic ecgs. | arxiv:1111.5926 |
in this paper we, first, present a class of charged rotating solutions in four - dimensional einstein - maxwell - dilaton gravity with zero and liouville - type potentials. we find that these solutions can present a black hole / string with two regular horizons, an extreme black hole or a naked singularity provided the parameters of the solutions are chosen suitable. we also compute the conserved and thermodynamic quantities, and show that they satisfy the first law of thermodynamics. second, we obtain the ( $ n + 1 $ % ) - dimensional rotating solutions in einstein - dilaton gravity with liouville - type potential. we find that these solutions can present black branes, naked singularities or spacetimes with cosmological horizon if one chooses the parameters of the solutions correctly. again, we find that the thermodynamic quantities of these solutions satisfy the first law of thermodynamics. | arxiv:hep-th/0412049 |
we establish a necessary and sufficient condition for the quantile process based on iid sampling to converge in distribution in $ l ^ 1 ( 0, 1 ) $. the condition is that the quantile function is locally absolutely continuous on the open unit interval and satisfies a slight strengthening of square integrability. we further establish a necessary and sufficient condition for the p - p process based on iid sampling from two populations to converge in distribution in $ l ^ 1 ( 0, 1 ) $. the condition is that the p - p curve is locally absolutely continuous on the open unit interval. if either process converges in distribution then it may be approximated using the bootstrap. | arxiv:2502.01254 |
in this paper, we introduce and characterize max - doubly stochastic matrices within the framework of max algebra, where the operations are defined as $ x \ oplus y = \ max ( x, y ) $ and $ x \ otimes y = xy $. we explore the fundamental properties of max - doubly stochastic matrices and their role in vector majorization. specifically, we establish that for vectors $ x $ and $ y $ in max algebra, $ x $ is majorized by $ y $ if there exists a max - doubly stochastic matrix $ d $ such that $ x = d \ otimes y $. this provides a new approach to majorization theory within tropical mathematics and enhances the understanding of vector relations in max algebra. | arxiv:2504.19340 |
for arbitrary permutations. for example, tr ( abc ) = tr ( bac ), in general. also, the trace of a matrix is equal to that of its transpose, that is, tr ( a ) = tr ( a t ). { \ displaystyle \ operatorname { tr } ( { \ mathbf { a } } ) = \ operatorname { tr } ( { \ mathbf { a } } ^ { \ rm { t } } ). } = = = = determinant = = = = the determinant of a square matrix a ( denoted det ( a ) or | a | ) is a number encoding certain properties of the matrix. a matrix is invertible if and only if its determinant is nonzero. its absolute value equals the area ( in r 2 { \ displaystyle \ mathbb { r } ^ { 2 } } ) or volume ( in r 3 { \ displaystyle \ mathbb { r } ^ { 3 } } ) of the image of the unit square ( or cube ), while its sign corresponds to the orientation of the corresponding linear map : the determinant is positive if and only if the orientation is preserved. the determinant of 2 - by - 2 matrices is given by det [ a b c d ] = a d − b c. { \ displaystyle \ det { \ begin { bmatrix } a & b \ \ c & d \ end { bmatrix } } = ad - bc. } the determinant of 3 - by - 3 matrices involves 6 terms ( rule of sarrus ). the more lengthy leibniz formula generalizes these two formulae to all dimensions. the determinant of a product of square matrices equals the product of their determinants : det ( a b ) = det ( a ) ⋅ det ( b ), { \ displaystyle \ det ( { \ mathbf { ab } } ) = \ det ( { \ mathbf { a } } ) \ cdot \ det ( { \ mathbf { b } } ), } or using alternate notation : | a b | = | a | ⋅ | b |. { \ displaystyle | { \ mathbf { ab } } | = | { \ mathbf { a } } | \ cdot | { \ mathbf { b } } |. } adding a multiple of any row to another row, or a multiple of any column to another column, does not change | https://en.wikipedia.org/wiki/Matrix_(mathematics) |
we present a fluid dynamics video showing simulations of flexible bodies falling in an inviscid fluid. vortex sheets are shed from the trailing edges of the bodies according to the kutta condition. the basic behavior is a repeated series of accelerations to a critical speed at which the sheet buckles, and rapidly decelerates, shedding large vortices. examples of persistent circling, quasi - periodic flapping, and more complex trajectories are shown. | arxiv:1008.0802 |
the boolardy engineering test array is a 6 x 12 m dish interferometer and the prototype of the australian square kilometre array pathfinder ( askap ), equipped with the first generation of askap ' s phased array feed ( paf ) receivers. these facilitate rapid wide - area imaging via the deployment of simultaneous multiple beams within a 30 square degree field of view. by cycling the array through 12 interleaved pointing positions and using 9 digitally formed beams we effectively mimic a traditional 1 hour x 108 pointing survey, covering 150 square degrees over 711 - 1015 mhz in 12 hours of observing time. three such observations were executed over the course of a week. we verify the full bandwidth continuum imaging performance and stability of the system via self - consistency checks and comparisons to existing radio data. the combined three epoch image has arcminute resolution and a 1 - sigma thermal noise level of 375 micro - jy per beam, although the effective noise is a factor 3 higher due to residual sidelobe confusion. from this we derive a catalogue of 3, 722 discrete radio components, using the 35 percent fractional bandwidth to measure in - band spectral indices for 1, 037 of them. a search for transient events reveals one significantly variable source within the survey area. the survey covers approximately two - thirds of the spitzer south pole telescope deep field. this pilot project demonstrates the viability and potential of using pafs to rapidly and accurately survey the sky at radio wavelengths. | arxiv:1601.05857 |
we introduce a highly performant 3d object detector for point clouds using the detr framework. the prior attempts all end up with suboptimal results because they fail to learn accurate inductive biases from the limited scale of training data. in particular, the queries often attend to points that are far away from the target objects, violating the locality principle in object detection. to address the limitation, we introduce a novel 3d vertex relative position encoding ( 3dv - rpe ) method which computes position encoding for each point based on its relative position to the 3d boxes predicted by the queries in each decoder layer, thus providing clear information to guide the model to focus on points near the objects, in accordance with the principle of locality. in addition, we systematically improve the pipeline from various aspects such as data normalization based on our understanding of the task. we show exceptional results on the challenging scannetv2 benchmark, achieving significant improvements over the previous 3detr in $ \ rm { ap } _ { 25 } $ / $ \ rm { ap } _ { 50 } $ from 65. 0 \ % / 47. 0 \ % to 77. 8 \ % / 66. 0 \ %, respectively. in addition, our method sets a new record on scannetv2 and sun rgb - d datasets. code will be released at http : / / github. com / yichaoshen - ms / v - detr. | arxiv:2308.04409 |
in this work, multilayer crisscross error and erasures are considered, which affect entire rows and columns in the matrices of a list of matrices. to measure such errors and erasures, the multi - cover metric is introduced. several bounds are derived, including a singleton bound, and maximum multi - cover distance ( mmcd ) codes are defined as those attaining it. duality, puncturing and shortening of linear mmcd codes are studied. it is shown that the dual of a linear mmcd code is not necessarily mmcd, and those satisfying this duality condition are defined as dually mmcd codes. finally, some constructions of codes in the multi - cover metric are given, including dually mmcd codes, together with efficient decoding algorithms for them. | arxiv:2203.07238 |
various distribution free goodness - of - fit test procedures have been extracted from literature. we present two new binning free tests, the univariate three - region - test and the multivariate energy test. the power of the selected tests with respect to different slowly varying distortions of experimental distributions are investigated. none of the tests is optimum for all distortions. the energy test has high power in many applications and is superior to the chi ^ 2 test. | arxiv:math/0207300 |
we experimentally investigated the characteristics of two - photon transmission resonances in rb vapor cells with different amount of buffer gas under the conditions of steady - state coherent population trapping ( cpt ) and pulsed raman - ramsey ( rr - ) cpt interrogation scheme. we particularly focused on the influence of the rb atoms diffusing in and out of the laser beam. we showed that this effect modifies the shape of both cpt and raman - ramsey resonances, as well as their projected performance for cpt clock applications. in particular we found that at moderate buffer gas pressures rr - cpt did not improved the projected atomic clock stability compare to the regular steady - state cpt resonance. | arxiv:1511.07550 |
solving complex visual tasks such as " who invented the musical instrument on the right? " involves a composition of skills : understanding space, recognizing instruments, and also retrieving prior knowledge. recent work shows promise by decomposing such tasks using a large language model ( llm ) into an executable program that invokes specialized vision models. however, generated programs are error - prone : they omit necessary steps, include spurious ones, and are unable to recover when the specialized models give incorrect outputs. moreover, they require loading multiple models, incurring high latency and computation costs. we propose visual program distillation ( vpd ), an instruction tuning framework that produces a vision - language model ( vlm ) capable of solving complex visual tasks with a single forward pass. vpd distills the reasoning ability of llms by using them to sample multiple candidate programs, which are then executed and verified to identify a correct one. it translates each correct program into a language description of the reasoning steps, which are then distilled into a vlm. extensive experiments show that vpd improves the vlm ' s ability to count, understand spatial relations, and reason compositionally. our vpd - trained pali - x outperforms all prior vlms, achieving state - of - the - art performance across complex vision tasks, including mmbench, ok - vqa, a - okvqa, tallyqa, pope, and hateful memes. an evaluation with human annotators also confirms that vpd improves model response factuality and consistency. finally, experiments on content moderation demonstrate that vpd is also helpful for adaptation to real - world applications with limited data. | arxiv:2312.03052 |
we study the coulomb branch of class $ \ mathcal { s } _ k $ $ \ mathcal { n } = 1 $ scfts by constructing and analyzing their spectral curves. | arxiv:1512.06079 |
in superconducting quantum processors, the predictability of device parameters is of increasing importance as many labs scale up their systems to larger sizes in a 3d - integrated architecture. in particular, the properties of superconducting resonators must be controlled well to ensure high - fidelity multiplexed readout of qubits. here we present a method, based on conformal mapping techniques, to predict a resonator ' s parameters directly from its 2d cross - section, without computationally heavy and time - consuming 3d simulation. we demonstrate the method ' s validity by comparing the calculated resonator frequency and coupling quality factor with those obtained through 3d finite - element - method simulation and by measurement of 15 resonators in a flip - chip - integrated architecture. we achieve a discrepancy of less than 2 % between designed and measured frequencies, for 6 - ghz resonators. we also propose a design method that reduces the sensitivity of the resonant frequency to variations in the inter - chip spacing. | arxiv:2305.05502 |
we study the interaction of small amplitude, long wavelength solitary waves in the fermi - pasta - ulam model with general nearest - neighbor interaction potential. we establish global - in - time existence and stability of counter - propagating solitary wave solutions. these solutions are close to the linear superposition of two solitary waves for large positive and negative values of time ; for intemediate values of time these solutions describe the interaction of two counterpropagating pulses. these solutions are stable with respect to perturbations in $ \ ell ^ 2 $ and asymptotically stable with respect to perturbations which decay exponentially at spatial $ \ pm \ infty $. } | arxiv:0806.1637 |
inverse imaging problems are inherently under - determined, and hence it is important to employ appropriate image priors for regularization. one recent popular prior - - - the graph laplacian regularizer - - - assumes that the target pixel patch is smooth with respect to an appropriately chosen graph. however, the mechanisms and implications of imposing the graph laplacian regularizer on the original inverse problem are not well understood. to address this problem, in this paper we interpret neighborhood graphs of pixel patches as discrete counterparts of riemannian manifolds and perform analysis in the continuous domain, providing insights into several fundamental aspects of graph laplacian regularization for image denoising. specifically, we first show the convergence of the graph laplacian regularizer to a continuous - domain functional, integrating a norm measured in a locally adaptive metric space. focusing on image denoising, we derive an optimal metric space assuming non - local self - similarity of pixel patches, leading to an optimal graph laplacian regularizer for denoising in the discrete domain. we then interpret graph laplacian regularization as an anisotropic diffusion scheme to explain its behavior during iterations, e. g., its tendency to promote piecewise smooth signals under certain settings. to verify our analysis, an iterative image denoising algorithm is developed. experimental results show that our algorithm performs competitively with state - of - the - art denoising methods such as bm3d for natural images, and outperforms them significantly for piecewise smooth images. | arxiv:1604.07948 |
let $ x $ be an infinite graph of bounded degree ; e. g., the cayley graph of a free product of finite groups. if $ g $ is a finite graph covered by $ x $, it is said to be $ x $ - ramanujan if its second - largest eigenvalue $ \ lambda _ 2 ( g ) $ is at most the spectral radius $ \ rho ( x ) $ of $ x $, and more generally $ k $ - quasi - $ x $ - ramanujan if $ \ lambda _ k ( g ) $ is at most $ \ rho ( x ) $. in case $ x $ is the infinite $ \ delta $ - regular tree, this reduces to the well known notion of a finite $ \ delta $ - regular graph being ramanujan. inspired by the interlacing polynomials method of marcus, spielman, and srivastava, we show the existence of infinitely many $ k $ - quasi - $ x $ - ramanujan graphs for a variety of infinite $ x $. in particular, $ x $ need not be a tree ; our analysis is applicable whenever $ x $ is what we call an additive product graph. this additive product is a new construction of an infinite graph $ \ mathsf { addprod } ( a _ 1, \ dots, a _ c ) $ from finite ' atom ' graphs $ a _ 1, \ dots, a _ c $ over a common vertex set. it generalizes the notion of the free product graph $ a _ 1 * \ cdots * a _ c $ when the atoms $ a _ j $ are vertex - transitive, and it generalizes the notion of the universal covering tree when the atoms $ a _ j $ are single - edge graphs. key to our analysis is a new graph polynomial $ \ alpha ( a _ 1, \ dots, a _ c ; x ) $ that we call the additive characteristic polynomial. it generalizes the well known matching polynomial $ \ mu ( g ; x ) $ in case the atoms $ a _ j $ are the single edges of $ g $, and it generalizes the $ r $ - characteristic polynomial introduced in [ ravichandran ' 16, leake - ravichandran ' 18 ]. we show that $ \ alpha ( a _ 1, \ dots, a _ c ; x ) $ is real - rooted, and all of its roots have magnitude at most $ \ rho ( \ mathsf { | arxiv:1904.03500 |
microlensing of a gamma - ray burst afterglow by an intervening star can be used to infer the radial structure of the afterglow image. near the peak of the microlensing event, the outer edge of the image is more highly magnified than its central region, whereas the situation is reversed at later times due to the rapid radial expansion of the image on the sky. thus, the microlensed afterglow light curve can be inverted to recover the self - similar radial intensity profile of the afterglow image. we calculate the expected errors in the recovered intensity profile as a function of the number of resolution elements, under the assumption that the afterglow and microlensing event parameters are known. for a point - mass lens and uniform source, we derive a simple scaling relation between these parameters and the resultant errors. the afterglow need not be monitored for its entire duration ; rather, observations from the peak magnification time t _ p of the microlensing event until 7 t _ p are sufficient to resolve the majority of the image. thus, microlensing events can be alerted by relatively infrequent observations of afterglows and then monitored intensively, without significant loss of information about the afterglow intensity profile. the relative intensity profile of about 1 % of all afterglows can be measured with 10 resolution elements to an accuracy of 1 % in the optical and 10 % in the infrared, using 4m - class telescopes. weak microlensing events with large impact parameters are more common ; we estimate that for about 10 % of afterglows the image profile may be inverted to a fractional accuracy 20 % through frequent optical observations. we also calculate the effects of external shear due to the host galaxy or a binary companion, and contamination by background light from the host galaxy. | arxiv:astro-ph/0102003 |
zinc and cadmium clusters interacting with a gupta potential have previously been identified as prototypical metallic systems that exhibiting disordered cluster structures. here, putative global minima of the potential energy have been located for these clusters for all sizes up to n < 125. although none of the usual structural forms are lowest in energy and many of the clusters have no overall order, strong structural preferences have been identified. many of the clusters are based on distorted oblate marks decahedra, where the distortion involves the bringing together of atoms on either side of a re - entrant groove of the marks decahedron. | arxiv:cond-mat/0306225 |
we present results of the suzaku observation of the dipping, periodically bursting low mass x - ray binary xb 1323 - 619 in which we concentrate of the spectral evolution in dipping in the energy range 0. 8 - 70 kev. it is shown that spectral evolution in dipping is well - described by absorption on the bulge in the outer accretion disk of two continuum components : emission of the neutron star plus the dominant, extended comptonized emission of the accretion disk corona ( adc ). this model is further supported by detection of a relatively small, energy - independent decrease of flux above 20 kev due to thomson scattering. it is shown that this is consistent with the electron scattering expected of the bulge plasma. we address the recent proposal that the dip sources may be explained by an ionized absorber model giving a number of physical arguments against this model. in particular, that model is inconsistent with the extended nature of the adc for which the evidence is now overwhelming. | arxiv:0910.4258 |
we construct two functors from the submodule category of a self - injective representation - finite algebra $ \ lambda $ to the module category of the stable auslander algebra of $ \ lambda $. these functors factor through the module category of the auslander algebra of $ \ lambda $. moreover they induce equivalences from the quotient categories of the submodule category modulo their respective kernels and said kernels have finitely many indecomposable objects up to isomorphism. their construction uses a recollement of the module category of the auslander algebra induced by an idempotent and this recollement determines a characteristic tilting and cotilting module. if $ \ lambda $ is taken to be a nakayama algebra, then said tilting and cotilting module is a characteristic tilting module of a quasi - hereditary structure on the auslander algebra. we prove that the self - injective nakayama algebras are the only algebras with this property. | arxiv:1607.08504 |
we present a proof that quantum yang - mills theory can be consistently defined as a renormalized, perturbative quantum field theory on an arbitrary globally hyperbolic curved, lorentzian spacetime. to this end, we construct the non - commutative algebra of observables, in the sense of formal power series, as well as a space of corresponding quantum states. the algebra contains all gauge invariant, renormalized, interacting quantum field operators ( polynomials in the field strength and its derivatives ), and all their relations such as commutation relations or operator product expansion. it can be viewed as a deformation quantization of the poisson algebra of classical yang - mills theory equipped with the peierls bracket. the algebra is constructed as the cohomology of an auxiliary algebra describing a gauge fixed theory with ghosts and anti - fields. a key technical difficulty is to establish a suitable hierarchy of ward identities at the renormalized level that ensure conservation of the interacting brst - current, and that the interacting brst - charge is nilpotent. the algebra of physical interacting field observables is obtained as the cohomology of this charge. as a consequence of our constructions, we can prove that the operator product expansion closes on the space of gauge invariant operators. similarly, the renormalization group flow is proved not to leave the space of gauge invariant operators. | arxiv:0705.3340 |
we report the synthesis, magnetic susceptibility and crystal structure analysis for nbb2 + x ( x = 0. 0 to 1. 0 ) samples. the study facilitates in finding a correlation among the lattice parameters, chemical composition and the superconducting transition temperature tc. rietveld analysis is done on the x - ray diffraction patterns of all synthesized samples to determine the lattice parameters. the a parameter decreases slightly and has a random variation with increasing x, while c parameter increases from 3. 26 for pure nbb2 to 3. 32 for x = 0. 4 i. e. nbb2. 4. with higher boron content ( x > 0. 4 ) the c parameter decreases slightly. the stretching of lattice in c direction induces superconductivity in the non - stoichiometric niobium boride. pure nbb2 is non - superconductor while the other nbb2 + x ( x > 0. 0 ) samples show diamagnetic signal in the temperature range 8. 9 - 11k. magnetization measurements ( m - h ) at a fixed temperature of 5k are also carried out in both increasing and decreasing directions of field. the estimated lower and upper critical fields ( hc1 & hc2 ) as viewed from m - h plots are around 590 and 2000oe respectively for nbb2. 6 samples. in our case, superconductivity is achieved in nbb2 by varying the nb / b ratios, rather than changing the processing conditions as reported by others. | arxiv:0807.1198 |
in molecular discovery and drug design, structure - property relationships and activity landscapes are often qualitatively or quantitatively analyzed to guide the navigation of chemical space. the roughness ( or smoothness ) of these molecular property landscapes is one of their most studied geometric attributes, as it can characterize the presence of activity cliffs, with rougher landscapes generally expected to pose tougher optimization challenges. here, we introduce a general, quantitative measure for describing the roughness of molecular property landscapes. the proposed roughness index ( rogi ) is loosely inspired by the concept of fractal dimension and strongly correlates with the out - of - sample error achieved by machine learning models on numerous regression tasks. | arxiv:2207.09250 |
plastic deformation in crystalline materials is controlled by the motion and interactions of dislocations [ and 17 ]. discrete dislocation dynamics ( ddd ) simulations have now existed for about 25 years to investigate plastic flow at the mesoscale, which lies at a critical position between two very different scales. at small scale, atomistic simulations are particularly adapted to investigate the core structure or mobility of individual dislocations, while continuous approaches can simulate the complete and continuous mechanical behaviour at the scale of the components. the purpose of ddd is to simulate the evolution of large dislocation ensembles in reaction to an external load and to assess the collective behaviour of dislocations. | arxiv:2001.01604 |
this paper introduces posterior mean matching ( pmm ), a new method for generative modeling that is grounded in bayesian inference. pmm uses conjugate pairs of distributions to model complex data of various modalities like images and text, offering a flexible alternative to existing methods like diffusion models. pmm models iteratively refine noisy approximations of the target distribution using updates from online bayesian inference. pmm is flexible because its mechanics are based on general bayesian models. we demonstrate this flexibility by developing specialized examples : a generative pmm model of real - valued data using the normal - normal model, a generative pmm model of count data using a gamma - poisson model, and a generative pmm model of discrete data using a dirichlet - categorical model. for the normal - normal pmm model, we establish a direct connection to diffusion models by showing that its continuous - time formulation converges to a stochastic differential equation ( sde ). additionally, for the gamma - poisson pmm, we derive a novel sde driven by a cox process, which is a significant departure from traditional brownian motion - based generative models. pmms achieve performance that is competitive with generative models for language modeling and image generation. | arxiv:2412.13286 |
we derive scaling limits for integral functionals of it \ ^ o processes with fast nonlinear mean - reversion speed. we show that in these limits, the fast mean - reverting process is " averaged out " by integrating against its invariant measure. these convergence results hold uniformly in probability and, under mild integrability conditions, also in $ \ mathcal { s } ^ p $. they are a crucial building block for the analysis of portfolio choice models with small superlinear transaction costs, carried out in the companion paper of the present study. | arxiv:1710.11202 |
the physical model of a nonrelativistic quantized schrodinger ' s electron ( se ) is offered. the behaviour of the se well spread elementary electric charge had been understood by means of two independent and different in a frequency and size motions. the description of this resultant motion may be done by substitution of the classical wiener continuous integral with the quantized feynmam continuous integral. there are possibility to show by means of the existent not only formal but substantial analogy between the quadratic differential wave equation in partial derivatives of schrodinger and quadratic differential particle equation in partial derivatives of hamilton - jacoby that the addition of a kinetic energy of the stochastic harmonic oscillation of some quantized micro particles to the kinetic energy of classical motion of the same micro particles formally determines their wave behaviour. it turns out the stochastic motion of the quantized micro particles powerfully to break up the smooth thin line of the classical motion of the same micro particle in many broad cylindrically spread path. the se participate in stochastically roughly determined circumferences within different flats and with different radii, with centres which are successively arranjed over short and very disorderly orientated lines. therefore the quantized motion of some micro particle cannot be descripted by smooth thin well contured ( focused ) line, describing the classical motion of the macro particle. | arxiv:quant-ph/0001078 |
here we prove that for a 2k2 - free graph g with maximum degree greater than or equal to 5, the chromatic number is less than or equal to max { maximum degree - 1, maximum clique size }. this implies that borodin & kostochka conjecture is true for 2k2 - free graphs. | arxiv:1702.00914 |
we show that for some hopf subalgebras in u _ f ( so ( m ) ) nontrivially deformed by a twist f it is possible to find the nonlinear primitive copies. this enlarges the possibilities to construct chains of twists. for orthogonal algebra u ( so ( m ) ) we present a method to compose the full chains with carrier space as large as the borel subalgebra b ( so ( m ) ). these chains can be used to construct the new deformed yangians. | arxiv:math/0008044 |
a comprehensive model atom for fe with more than 3000 energy levels is presented. as a test and first application of this model atom, fe abundances are determined for the sun and five stars with well determined stellar parameters and high - quality observed spectra. non - lte leads to systematically depleted total absorption in the fe i lines and to positive abundance corrections in agreement with the previous studies, however, the magnitude of non - lte effect is smaller compared to the earlier results. non - lte corrections do not exceed 0. 1 dex for the solar metallicity and mildly metal - deficient stars, and they vary within 0. 21 dex and 0. 35 dex in the very metal - poor stars hd 84937 and hd 122563, respectively, depending on the assumed efficiency of collisions with hydrogen atoms. based on the analysis of the fe i / fe ii ionization equilibrium in these two stars, we recommend to apply the drawin formalism in non - lte studies of fe with a scaling factor of 0. 1. for the fe ii lines, non - lte corrections do not exceed 0. 01 dex in absolute value. the solar non - lte abundance obtained from 54 fe i lines is 7. 56 + - 0. 09 and the abundance from 18 fe ii lines varies between 7. 41 + - 0. 11 and 7. 56 + - 0. 05 depending on the source of the gf - values. thus, gf - values available for the iron lines are not accurate enough to pursue high - accuracy absolute abundance determinations. lines of fe i give, on average, a 0. 1 dex lower abundance compared to those of fe ii lines for hd 61421 and hd 102870, even when applying a differential analysis relative to the sun. a disparity between fe i and fe ii points to problems of stellar atmosphere modelling or / and effective temperature determination. | arxiv:1101.4570 |
as a tool for studying the structure of nuclei far off stability the technique of gamma - ray spectroscopy after low - energy single - nucleon transfer reactions with radioactive nuclear beams in inverse kinematics was investigated. modules of the miniball germanium array and a thin position - sensitive parallel plate avalanche counter ( ppac ) to be employed in future experiments at rex - isolde were used in a test experiment performed with a stable 36s beam on deuteron and 9be targets. it is demonstrated that the doppler broadening of gamma lines detected by the miniball modules is considerably reduced by exploiting their segmentation, and that for beam intensities up to 10 ^ 6 particles / s the ppac positioned around zero degrees with respect to the beam axis allows not only to significantly reduce the gamma background by requiring coincidences with the transfer products but also to control the beam and its intensity by single particle counting. the predicted large neutron pickup cross sections of neutron - rich light nuclei on 2h and 9be targets at rex - isolde energies of 2. 2 mev a are confirmed. | arxiv:nucl-ex/0010005 |
we experimentally study the influence of 1 - 40 ghz radiation on the resistance of normal ( n ) mesoscopic conductors coupled to superconducting ( s ) loops ( andreev interferometers ). at low rf amplitudes we observe the usual h / 2e superconducting - phase - periodic resistance oscillations as a function of applied magnetic flux. we find that the oscillations acquire a pi - shift with increasing rf amplitude, and consistent with this result the resistance at fixed phase is an oscillating function of the rf amplitude. the results are explained qualitatively as a consequence of two processes. the first is the modulation of the phase difference between the n / s interfaces by the rf field, with the resistance adiabatically following the phase. the second process is the change in the electron temperature caused by the rf field. from the data the response time of the andreev interferometer is estimated to be < 40ps. however there are a number of experimental features which remain unexplained ; these include the drastic difference in the behaviour of the resistance at different phases as a function of rf frequency and amplitude, and the existence of a " window of transparency " where heating effects are weak enough to allow for the pi - shift. a microscopic theory describing the influence of rf radiation on andreev interferometers is required. | arxiv:1003.2176 |
edge artificial intelligence ( ai ) incorporates a network of interconnected systems and devices that receive, cache, process, and analyze data in close communication with the location where the data is captured with ai technology. recent advancements in ai efficiency, the widespread use of internet of things ( iot ) devices, and the emergence of edge computing have unlocked the enormous scope of edge ai. edge ai aims to optimize data processing efficiency and velocity while ensuring data confidentiality and integrity. despite being a relatively new field of research from 2014 to the present, it has shown significant and rapid development over the last five years. this article presents a systematic literature review for edge ai to discuss the existing research, recent advancements, and future research directions. we created a collaborative edge ai learning system for cloud and edge computing analysis, including an in - depth study of the architectures that facilitate this mechanism. the taxonomy for edge ai facilitates the classification and configuration of edge ai systems while examining its potential influence across many fields through compassing infrastructure, cloud computing, fog computing, services, use cases, ml and deep learning, and resource management. this study highlights the significance of edge ai in processing real - time data at the edge of the network. additionally, it emphasizes the research challenges encountered by edge ai systems, including constraints on resources, vulnerabilities to security threats, and problems with scalability. finally, this study highlights the potential future research directions that aim to address the current limitations of edge ai by providing innovative solutions. | arxiv:2407.04053 |
we consider $ n $ classical particles interacting via the coulomb potential in spatial dimension $ d $ and in the presence of an external trap, at equilibrium at inverse temperature $ \ beta $. in the large $ n $ limit, the particles are confined within a droplet of finite size. we study smooth linear statistics, i. e. the fluctuations of sums of the form $ { \ cal l } _ n = \ sum _ { i = 1 } ^ n f ( { \ bf x } _ i ) $, where $ { \ bf x } _ i $ ' s are the positions of the particles and where $ f ( { \ bf x } _ i ) $ is a sufficiently regular function. there exists at present standard results for the first and second moments of $ { \ cal l } _ n $ in the large $ n $ limit, as well as associated central limit theorems in general dimension and for a wide class of confining potentials. here we obtain explicit expressions for the higher order cumulants of $ { \ cal l } _ n $ at large $ n $, when the function $ f ( { \ bf x } ) = f ( | { \ bf x } | ) $ and the confining potential are both rotationnally invariant. a remarkable feature of our results is that these higher cumulants depend only on the value of $ f ' ( | { \ bf x } | ) $ and its higher order derivatives evaluated exactly at the boundary of the droplet, which in this case is a $ d $ - dimensional sphere. in the particular two - dimensional case $ d = 2 $ at the special value $ \ beta = 2 $, a connection to the ginibre ensemble allows us to derive these results in an alternative way using the tools of determinantal point processes. finally we also obtain the large deviation form of the full probability distribution function of $ { \ cal l } _ n $. | arxiv:2310.16420 |
we investigate point arrangements $ v _ i \ in \ mathbb r ^ d, i \ in \ { 1,..., n \ } $ with certain prescribed symmetries. the arrangement space of $ v $ is the column span of the matrix in which the $ v _ i $ are the rows. we characterize properties of $ v $ in terms of the arrangement space, e. g. we characterize whether an arrangement possesses certain symmetries or whether it can be continuously deformed into another arrangement while preserving symmetry in the process. we show that whether a symmetric arrangement can be continuously deformed into its mirror image depends non - trivially on several factors, e. g. the decomposition of its representation into irreducible constituents, and whether we are in even or odd dimensions. | arxiv:1907.11120 |
multi - strange ca, sn and pb hypernuclei with $ \ lambda \ lambda $ pairing interaction are investigated within the hartree - fock - bogoliubov approach. the unknown $ \ lambda \ lambda $ pairing strength is calibrated to match with the maximal value for the prediction of the $ \ lambda $ pairing gap in uniform matter for densities and isospin asymmetries equivalent to those existing in multi - $ \ lambda $ hypernuclei. in this way, we provide an upper bound for the prediction of the $ \ lambda $ pairing gap and its effects in hypernuclei. the condensation energy is predicted to be about 3 ~ mev as a maximum value, yielding small corrections on density distributions and shell structure. in addition, conditions on both fermi energies and orbital angular momenta are expected to quench the nucleon - $ \ lambda $ pairing for most of hypernuclei. | arxiv:1803.05512 |
we present here a review of existing analytical methods to solve boundary value problems of diffusion in media containing n non - overlapping inclusions. | arxiv:1512.04379 |
we use new and published medium resolution 0. 6 - - 2. 5 $ \ mu $ m spectra of l and t dwarfs to develop a unified classification system for both of these new spectral classes. two indices of the system at 1. 2 $ \ mu $ m and 1. 5 $ \ mu $ m are based on nearby absorption bands of water vapor and two are associated with methane bands near 1. 6 $ \ mu $ m and 2. 2 $ \ mu $ m. the 1. 5 $ \ mu $ m index is monotonic through the l and t sequences, and forms the backbone of the system ; the indices for the other bands provide extensive, but only partial, coverage. we correlate the 1. 5 $ \ mu $ m index with continuum indices shortward of 1 $ \ mu $ m devised by others for classifying l dwarfs, in order to obtain a tight link between optical and infrared classifications. our proposed system defines ten spectral subclasses for l ( l0 - - l9 ) and nine for t ( t0 - - t8 ). the boundary between l and t is defined to be the onset of absorption by methane in the h band. methane absorption in the k band near 2. 2 $ \ mu $ m is found to begin approximately at l8. | arxiv:astro-ph/0109331 |
in this paper, the joule - thomson expansion of the higher dimensional nonlinearly ads black hole with power maxwell invariant source is investigated. the results show the joule - thomson coefficient has a zero point and a divergent point, which are coincide with the inversion temperature $ t _ i $ and the zero point of hawking temperature, respectively. the inversion temperature increases monotonously with inversion pressure. for high - pressure region, the inversion temperature decreases with the dimensionality $ d $ and the nonlinearity parameter $ s $, whereas it increases with the charge $ q $. however, $ t _ i $ for low - pressure region increase with $ d $ and $ s $, while it decreases with $ q $. the ratio $ { \ eta _ { \ rm { bh } } } $ between the minimum of inversion temperature and the critical temperature does not depend on $ q $, it recovers the higher dimensional reissner - n \ " { o } rdstrom ads black hole case when $ s = 1 $. however, for $ s > 1 $, it becomes smaller and smaller as $ d $ increase and approaches a constant when $ d \ rightarrow \ infty $. finally, we found that increase of mass $ m $ and $ s $, or reduce the charge $ q $ and $ d $ can enhance the isenthalpic curve, and the effect of $ s $ on the isenthalpic curve is much greater than other parameters. | arxiv:2009.02172 |
the universal gr \ " obner basis of an ideal is a gr \ " obner basis with respect to all term orders simultaneously. the aim of this paper is to present an algorithmic approach to compute the universal gr \ " obner basis for the toric ideal corresponding to an undirected graph, based on the theoretically knowledge of this set and on a recent, efficiently computable algorithmic characterization of the graver basis of the ideal. | arxiv:1307.7224 |
multimodal foundation models offer promising advancements for enhancing driving perception systems, but their high computational and financial costs pose challenges. we develop a method that leverages foundation models to refine predictions from existing driving perception models - - such as enhancing object classification accuracy - - while minimizing the frequency of using these resource - intensive models. the method quantitatively characterizes uncertainties in the perception model ' s predictions and engages the foundation model only when these uncertainties exceed a pre - specified threshold. specifically, it characterizes uncertainty by calibrating the perception model ' s confidence scores into theoretical lower bounds on the probability of correct predictions using conformal prediction. then, it sends images to the foundation model and queries for refining the predictions only if the theoretical bound of the perception model ' s outcome is below the threshold. additionally, we propose a temporal inference mechanism that enhances prediction accuracy by integrating historical predictions, leading to tighter theoretical bounds. the method demonstrates a 10 to 15 percent improvement in prediction accuracy and reduces the number of queries to the foundation model by 50 percent, based on quantitative evaluations from driving datasets. | arxiv:2410.01144 |
let $ e / f $ be an elliptic curve over a number field $ f $ with complex multiplication by the ring of integers in an imaginary quadratic field $ k $. we give a complete proof of the conjecture of birch and swinnerton - dyer for $ e / f $, as well as its equivariant refinement formulated by gross, under the assumption that $ l ( e / f, 1 ) \ neq 0 $ and that $ f ( e _ { tors } ) / k $ is abelian. we also prove analogous results for cm abelian varieties $ a / k $. | arxiv:2206.09874 |
we measure the spin lattice relaxation of the in ( 1 ) nuclei in the cemin _ 5 materials, extract quantitative information about the low energy spin dynamics of the lattice of ce moments in both cerhin _ 5 and cecoin _ 5, and identify a crossover in the normal state. above a temperature t * the ce lattice exhibits " kondo gas " behavior characterized by local fluctuations of independently screened moments ; below t * both systems exhibit a " kondo liquid " regime in which interactions between the local moments contribute to the spin dynamics. both the antiferromagnetic and superconducting ground states in these systems emerge from the " kondo liquid " regime. our analysis provides strong evidence for quantum criticality in cecoin _ 5. | arxiv:cond-mat/0205354 |
randomized smoothing is considered to be the state - of - the - art provable defense against adversarial perturbations. however, it heavily exploits the fact that classifiers map input objects to class probabilities and do not focus on the ones that learn a metric space in which classification is performed by computing distances to embeddings of classes prototypes. in this work, we extend randomized smoothing to few - shot learning models that map inputs to normalized embeddings. we provide analysis of lipschitz continuity of such models and derive robustness certificate against $ \ ell _ 2 $ - bounded perturbations that may be useful in few - shot learning scenarios. our theoretical results are confirmed by experiments on different datasets. | arxiv:2202.01186 |
one of interesting open questions for the high transition temperature ( tc ) superconductivity in sulfur hydrides is why high pressure phases of h3s have extremely high tc ' s. recently, it has been pointed out that the presence of the van hove singularities ( vhs ) around the fermi level is crucial. however, while there have been quantitative estimates of tc based on the migdal - eliashberg theory, the energy dependence of the density of states ( dos ) has been neglected to simplify the eliashberg equation. in this study, we go beyond the constant dos approximation and explicitly consider the electronic structure over 40ev around the fermi level. in contrast with the previous conventional calculations, this approach with a sufficiently large number of matsubara frequencies enables us to calculate tc without introducing the empirical pseudo coulomb potential. we show that while h3s has much higher tc than h2s for which the vhs is absent, the constant dos approximation employed so far seriously overestimates ( underestimates ) tc by ~ 60k ( ~ 10k ) for h3s ( h2s ). we then discuss the impact of the strong electron - phonon coupling on the electronic structure with and without the vhs and how it affects the superconductivity. especially, we focus on ( 1 ) the feedback effect in the self - consistent calculation of the self - energy, ( 2 ) the effect of the energy shift due to the zero - point motion, and ( 3 ) the effect of the changes in the phonon frequencies due to strong anharmonicity. we show that the effect of ( 1 ) - ( 3 ) on tc is about 10 - 30k for both h3s and h2s. eventually, tc is estimated to be 181k for h3s at 250gpa and 34k for h2s at 140gpa, which explains the pressure dependence of tc observed in the experiment. in addition, we evaluate the lowest order vertex correction beyond the migdal - eliashberg theory and discuss the validity of the migdal approximation for sulfur hydrides. | arxiv:1512.07365 |
we report a novel class microwave photonic ( mwp ) notch filter with a very narrow isolation bandwidth ( 10 mhz ), an ultrahigh stopband rejection ( > 60 db ), a wide frequency tuning ( 1 - 30 ghz ), and flexible bandwidth reconfigurability ( 10 - 65 mhz ). this record performance is enabled by a new concept of sidebands amplitude and phase controls using an electro - optic modulator and an optical filter. this new concept enables energy efficient operation in active mwp notch filters, and opens up the pathway to enable low - power nanophotonic devices as high performance rf filters. | arxiv:1308.1146 |
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