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analogical proportions are statements expressed in the form " a is to b as c is to d " and are used for several reasoning and classification tasks in artificial intelligence and natural language processing ( nlp ). in this paper, we focus on morphological tasks and we propose a deep learning approach to detect morphological analogies. we present an empirical study to see how our framework transfers across languages, and that highlights interesting similarities and differences between these languages. in view of these results, we also discuss the possibility of building a multilingual morphological model. | arxiv:2108.03938 |
disorder effects are especially pronounced around nodal points in linearly dispersing bandstructures as present in graphene or weyl semimetals. despite the enormous experimental and numerical progress, even a simple quantity like the average density of states cannot be assessed quantitatively by analytical means. we demonstrate how this important problem can be solved employing the functional renormalization group method and, for the two dimensional case, demonstrate excellent agreement with reference data from numerical simulations based on tight - binding models. in three dimensions our analytic results also improve drastically on existing approaches. | arxiv:1704.08457 |
business ontology can enhance the successful development of complex enterprise system ; this is being achieved through knowledge sharing and the ease of communication between every entity in the domain. through human semantic interaction with the web resources, machines to interpret the data published in a machine interpretable form under web. however, the theoretical practice of business ontology in ecommerce domain is quite a few especially in the section of electronic transaction, and the various techniques used to obtain efficient communication across spheres are error prone and are not always guaranteed to be efficient in obtaining desired result due to poor semantic integration between entities. to overcome the poor semantic integration this research focuses on proposed ontology called lb2co, which combines the framework of idef5 & snap as an analysis tool, for automated recommendation of product and services and create effective ontological framework for b2c transaction & communication across different business domains that facilitates the interoperability & integration of b2c transactions over the web. | arxiv:1401.0943 |
it is shown that a normalized complex hadamard matrix of order $ 6 $ having three distinct columns, each containing at least one $ - 1 $ entry necessarily belongs to the transposed fourier family, or to the family of $ 2 $ - circulant complex hadamard matrices. the proofs rely on solving polynomial system of equations by gr \ " obner basis techniques, and make use of a structure theorem concerning regular hadamard matrices. as a consequence, members of these two families can be easily recognized in practice. in particular, one can identify complex hadamard matrices appearing in known triplets of pairwise mutually unbiased bases in dimension $ 6 $. | arxiv:2405.09991 |
in this paper, we give an example of an autoequivalence with positive categorical entropy ( in the sense of dimitrov, haiden, katzarkov and kontsevich ) for any surface containing a ( - 2 ) - curve. then we show that this equivalence gives another counter - example to a conjecture proposed by kikuta and takahashi. in a second part, we study the action on cohomology induced by spherical twists composed with standard autoequivalences on a surface s and show that their spectral radii correspond to the topological entropy of the corresponding automorphisms of s. | arxiv:1909.02758 |
we first revisit the possibility of preserving the original flavor ratio of high energy cosmic neutrino flux by turning on a coupling between these neutrinos and ultra - light dark matter. we discuss the bound that can be set on such a coupling from the recent $ \ nu _ \ tau $ observation by icecube and outline the implications of the coupling for the eev range cosmic neutrino flux to be observed by upcoming neutrino detectors. we then focus on the $ 3 + 1 $ scheme when the active sterile oscillation length is of order of 1000 ~ km for eev range cosmic neutrinos. we show that within this scenario, the probability of survival of an active neutrino passing through the earth can be sizable, despite the fact that the mean free path of the eev neutrinos is much smaller than the earth radius. this opens up the possibility to have neutrino events similar to the two anomalous events reported by anita. | arxiv:2110.07222 |
three types of metallic nanostructures comprising niobium were investigated experimentally ; in all three types, electric transport at very low temperatures was governed by coulomb blockade effects. 1. thin film strips of niobium could be tuned into resistor strips by an electrochemical anodisation process, using microfabricated masks and in situ resistance monitoring. these resistors showed a transition from superconducting to insulating behaviour with increasing sheet resistance, occurring at a value approximately equal to the quantum resistance for cooper pairs, h / ( 4e ^ 2 ). 2. combining the anodisation technique with lateral size minimisation by shadow evaporation, devices in a single electron transistor - like configuration with two weak links and a small island between these were made. direct evidence for the coulomb blockade in the anodisation thinned niobium films was found when the transport characteristics could be modulated periodically by sweeping the voltage applied to a gate electrode placed on top of the structure. 3. conventional single electron transistors with al base electrodes, alo _ x barriers formed in situ by oxidation, and nb top electrodes were made by angular evaporation. the output current noise of such a transistor was measured as a function of bias voltage, gate voltage, and temperature. the low frequency noise was found to be dominated by charge input noise. the dependence of the noise on the bias voltage is consistent with self - heating of the transistor activating the noise sources. | arxiv:cond-mat/9901308 |
it is widely acknowledged that function symbols are an important feature in answer set programming, as they make modeling easier, increase the expressive power, and allow us to deal with infinite domains. the main issue with their introduction is that the evaluation of a program might not terminate and checking whether it terminates or not is undecidable. to cope with this problem, several classes of logic programs have been proposed where the use of function symbols is restricted but the program evaluation termination is guaranteed. despite the significant body of work in this area, current approaches do not include many simple practical programs whose evaluation terminates. in this paper, we present the novel classes of rule - bounded and cycle - bounded programs, which overcome different limitations of current approaches by performing a more global analysis of how terms are propagated from the body to the head of rules. results on the correctness, the complexity, and the expressivity of the proposed approach are provided. | arxiv:1512.04097 |
in this paper, firstly, we give the some fundamental properties of van der laan numbers. after, we define the circulant matrices c ( z ) which entries is third order linear recurrent sequence. in addition, we compute eigenvalues, spectral norm and determinant of this matrix. consequently, by using properties of this sequence, we obtain the eigenvalues, norms and determinants of circulant matrices with cordonnier, perrin and van der laan numbers. | arxiv:1406.5349 |
this paper proposes a digital amplitude - phase weighting array based a minimum variance multi - frequency distortionless restriction ( mvmfdr ) to aviod the frequency band signal distortion in digital beamformer and too short time delay line ( tdl ) requirement in analoge wideband tdl array. | arxiv:1005.3350 |
neuromorphic computing, inspired by the brain ' s parallel and energy - efficient processing, offers a transformative approach to artificial intelligence. in this study, we fabricated optimized spin - transfer torque nano - oscillators ( stnos ) and investigated their dynamic behaviors using a hybrid excitation scheme combining ac laser illumination and dc bias currents. laser - induced thermal gradients generate pulsed thermoelectric voltages ( $ v _ { \ text { ac } } $ ) via the tunnel magneto - seebeck ( tms ) effect, while the addition of bias currents enhances this response, producing both $ v _ { \ text { ac } } $ and a dc component ( $ v _ { \ text { dc } } $ ). magnetic field sweeps reveal distinct switching between parallel ( p ) and antiparallel ( ap ) magnetization states in both voltage components, supporting multistate memory applications. millivolt - range thermovoltage signals in open - circuit conditions demonstrate cmos compatibility, enabling simplified, scalable neuromorphic systems. under biased conditions, enhanced thermovoltage outputs exhibit intriguing phenomena, including spikes correlated with barkhausen jumps and double - switching behavior, offering insights into magnetization dynamics and vortex transitions. these features resemble neural spiking behavior, suggesting applications in spiking neural networks, reservoir computing, multistate logic, analog computing, and high - resolution sensing. by bridging spintronic phenomena with practical applications, this work provides a versatile platform for next - generation ai technologies and adaptive computing architectures. | arxiv:2501.00813 |
we review a recently developed method, based on a pseudoparticle representation of correlated electrons, to describe both fermi liquid and non - fermi liquid behavior in quantum impurity systems. the role of the projection onto the physical hilbert space and the impossibility of slave boson condensation are discussed. by summing the leading coherent spin and charge fluctuation processes in a fully self - consistent and gauge invariant way one obtains the correct infrared behavior of the pseudoparticles. the temperature dependence of the spin susceptibility for the single channel and two - channel anderson models is calculated and found to agree well with exact results. | arxiv:cond-mat/0005483 |
3d scene representations have gained immense popularity in recent years. methods that use neural radiance fields are versatile for traditional tasks such as novel view synthesis. in recent times, some work has emerged that aims to extend the functionality of nerf beyond view synthesis, for semantically aware tasks such as editing and segmentation using 3d feature field distillation from 2d foundation models. however, these methods have two major limitations : ( a ) they are limited by the rendering speed of nerf pipelines, and ( b ) implicitly represented feature fields suffer from continuity artifacts reducing feature quality. recently, 3d gaussian splatting has shown state - of - the - art performance on real - time radiance field rendering. in this work, we go one step further : in addition to radiance field rendering, we enable 3d gaussian splatting on arbitrary - dimension semantic features via 2d foundation model distillation. this translation is not straightforward : naively incorporating feature fields in the 3dgs framework encounters significant challenges, notably the disparities in spatial resolution and channel consistency between rgb images and feature maps. we propose architectural and training changes to efficiently avert this problem. our proposed method is general, and our experiments showcase novel view semantic segmentation, language - guided editing and segment anything through learning feature fields from state - of - the - art 2d foundation models such as sam and clip - lseg. across experiments, our distillation method is able to provide comparable or better results, while being significantly faster to both train and render. additionally, to the best of our knowledge, we are the first method to enable point and bounding - box prompting for radiance field manipulation, by leveraging the sam model. project website at : https : / / feature - 3dgs. github. io / | arxiv:2312.03203 |
pediatric low - grade neuroepithelial tumors ( plgnt ) are the most common pediatric cancer type, accounting for 40 % of brain tumors in children, and identifying plgnt molecular subtype is crucial for treatment planning. however, the gold standard to determine the plgnt subtype is biopsy, which can be impractical or dangerous for patients. this research improves the performance of convolutional neural networks ( cnns ) in classifying plgnt subtypes through mri scans by introducing a loss function that specifically improves the model ' s area under the receiver operating characteristic ( roc ) curve ( auroc ), offering a non - invasive diagnostic alternative. in this study, a retrospective dataset of 339 children with plgnt ( 143 braf fusion, 71 with braf v600e mutation, and 125 non - braf ) was curated. we employed a cnn model with monte carlo random data splitting. the baseline model was trained using binary cross entropy ( bce ), and achieved an auroc of 86. 11 % for differentiating braf fusion and braf v600e mutations, which was improved to 87. 71 % using our proposed auroc loss function ( p - value 0. 045 ). with multiclass classification, the auroc improved from 74. 42 % to 76. 59 % ( p - value 0. 0016 ). | arxiv:2402.03547 |
distributed distribution comparison aims to measure the distance between the distributions whose data are scattered across different agents in a distributed system and cannot even be shared directly among the agents. in this study, we propose a novel decentralized entropic optimal transport ( deot ) method, which provides a communication - efficient and privacy - preserving solution to this problem with theoretical guarantees. in particular, we design a mini - batch randomized block - coordinate descent ( mrbcd ) scheme to optimize the deot distance in its dual form. the dual variables are scattered across different agents and updated locally and iteratively with limited communications among partial agents. the kernel matrix involved in the gradients of the dual variables is estimated by a decentralized kernel approximation method, in which each agent only needs to approximate and store a sub - kernel matrix by one - shot communication and without sharing raw data. besides computing entropic wasserstein distance, we show that the proposed mrbcd scheme and kernel approximation method also apply to entropic gromov - wasserstein distance. we analyze our method ' s communication complexity and, under mild assumptions, provide a theoretical bound for the approximation error caused by the convergence error, the estimated kernel, and the mismatch between the storage and communication protocols. in addition, we discuss the trade - off between the precision of the eot distance and the strength of privacy protection when implementing our method. experiments on synthetic data and real - world distributed domain adaptation tasks demonstrate the effectiveness of our method. | arxiv:2301.12065 |
we introduce the macaulay2 package matchingpowers. it allows to compute and manipulate the matching powers of a monomial ideal. the basic theory of matching powers is explained and the main features of the package are presented. | arxiv:2312.13007 |
in this paper, we demonstrate that locally, the $ \ alpha ^ { \ prime } $ expansion of a string propagating in ads can be summed into a closed expression, where the $ \ alpha ' $ dependence is manifested. the t - dual of this sum exactly matches the expression controlling all genus expansion in the goparkumar - vafa formula, which in turn also matches the loop expansion of the chern - simons gauge theory. we therefore find an exact correspondence between the $ \ alpha ^ { \ prime } $ expansion for a string moving in ads and the genus expansion of a string propagating in four dimensional flat spacetime. we are then able to give a closed form of the $ \ alpha ' $ expansion for all values of $ \ sqrt { \ alpha ' } / r _ { ads } $. moreover, the correspondence makes it possible to conjecture the exact $ g _ s $ dependence of the strongly coupled theories. | arxiv:1703.05217 |
let m = p ( e ) be a ruled surface. we introduce metrics of finite volume on m whose singularities are parametrized by a parabolic structure over e. then, we generalise results of burns - - de bartolomeis and lebrun, by showing that the existence of a singular kahler metric of finite volume and constant non positive scalar curvature on m is equivalent to the parabolic polystability of e ; moreover these metrics all come from finite volume quotients of $ h ^ 2 \ times cp ^ 1 $. in order to prove the theorem, we must produce a solution of seiberg - witten equations for a singular metric g. we use orbifold compactifications $ \ overline m $ on which we approximate g by a sequence of smooth metrics ; the desired solution for g is obtained as the limit of a sequence of seiberg - witten solutions for these smooth metrics. | arxiv:math/0106077 |
we propose a decision triggered data transmission and collection ( dtdtc ) protocol for condition monitoring and anomaly detection in the industrial internet of things ( iiot ). in the iiot, the collection, processing, encoding, and transmission of the sensor readings are usually not for the reconstruction of the original data but for decision making at the fusion center. by moving the decision making process to the local end devices, the amount of data transmission can be significantly reduced, especially when normal signals with positive decisions dominate in the whole life cycle and the fusion center is only interested in collecting the abnormal data. the proposed concept combines compressive sensing, machine learning, data transmission, and joint decision making. the sensor readings are encoded and transmitted to the fusion center only when abnormal signals with negative decisions are detected. all the abnormal signals from the end devices are gathered at the fusion center for a joint decision with feedback messages forwarded to the local actuators. the advantage of such an approach lies in that it can significantly reduce the volume of data to be transmitted through wireless links. moreover, the introduction of compressive sensing can further reduce the dimension of data tremendously. an exemplary case, i. e., diesel engine condition monitoring, is provided to validate the effectiveness and efficiency of the proposed scheme compared to the conventional ones. | arxiv:2002.08857 |
we present a complete theoretical treatment of stark effects in doped silicon, whose predictions are supported by experimental measurements. a multi - valley effective mass theory, dealing non - perturbatively with valley - orbit interactions induced by a donor - dependent central cell potential, allows us to obtain a very reliable picture of the donor wave function within a relatively simple framework. variational optimization of the 1s donor binding energies calculated with a new trial wave function, in a pseudopotential with two fitting parameters, allows an accurate match of the experimentally determined donor energy levels, while the correct limiting behavior for the electronic density, both close to and far from each impurity nucleus, is captured by fitting the measured contact hyperfine coupling between the donor nuclear and electron spin. we go on to include an external uniform electric field in order to model stark physics : with no extra ad hoc parameters, variational minimization of the complete donor ground energy allows a quantitative description of the field - induced reduction of electronic density at each impurity nucleus. detailed comparisons with experimental values for the shifts of the contact hyperfine coupling reveal very close agreement for all the donors measured ( p, as, sb and bi ). finally, we estimate field ionization thresholds for the donor ground states, thus setting upper limits to the gate manipulation times for single qubit operations in kane - like architectures : the si : bi system is shown to allow for a gates as fast as around 10 mhz. | arxiv:1408.4375 |
we show that every finite - dimensional complex pointed hopf algebra with group of group - likes isomorphic to a sporadic group is a group algebra, except for the fischer group fi22, the baby monster and the monster. for these three groups, we give a short list of irreducible yetter - drinfeld modules whose nichols algebra is not known to be finite - dimensional. | arxiv:1001.1108 |
we present suzaku spectra of x - ray emission in the fields just off the lmc x - 3 sight line. ovii, oviii, and neix emission lines are clearly detected, suggesting the presence of an optically thin thermal plasma with an average temperature of 2. 4e6. this temperature is significantly higher than that inferred from existing x - ray absorption line data obtained with chandra grating observations of lmc x - 3, strongly suggesting that the gas is not isothermal. we then jointly analyze these data to characterize the spatial and temperature distributions of the gas. assuming a vertical exponential galactic disk model, we estimate the gas temperature and density at the galactic plane and their scale heights as 3. 6 ( 2. 9, 4. 7 ) e6 k and 1. 4 ( 0. 3, 3. 4 ) e - 3 cm ^ { - 3 } and 1. 4 ( 0. 2, 5. 2 ) kpc and $ 2. 8 ( 1. 0, 6. 4 ) $ kpc, respectively. this characterization can account for all the \ ovi line absorption, as observed in a fuse spectrum of lmc x - 3, but only predicts less than one tenth of the ovi line emission intensity typically detected at high galactic latitudes. the bulk of the ovi emission most likely arises at interfaces between cool and hot gases. | arxiv:0808.3985 |
this work deals with the challenge of learning and reasoning over language and vision data for the related downstream tasks such as visual question answering ( vqa ) and natural language for visual reasoning ( nlvr ). we design a novel cross - modality relevance module that is used in an end - to - end framework to learn the relevance representation between components of various input modalities under the supervision of a target task, which is more generalizable to unobserved data compared to merely reshaping the original representation space. in addition to modeling the relevance between the textual entities and visual entities, we model the higher - order relevance between entity relations in the text and object relations in the image. our proposed approach shows competitive performance on two different language and vision tasks using public benchmarks and improves the state - of - the - art published results. the learned alignments of input spaces and their relevance representations by nlvr task boost the training efficiency of vqa task. | arxiv:2005.06035 |
we show that slightly polydisperse disordered 2d foams can be used as a self - assembled template for isotropic photonic band gap ( pbg ) materials for transverse electric ( te ) polarization. calculations based on in - house experimental and simulated foam structures demonstrate that, at sufficient refractive index contrast, a dry foam organization with threefold nodes and long slender plateau borders is especially advantageous to open a large pbg. a transition from dry to wet foam structure rapidly closes the pbg mainly by formation of bigger fourfold nodes, filling the pbg with defect modes. by tuning the foam area fraction, we find an optimal quantity of dielectric material, which maximizes the pbg in experimental systems. the obtained results have a potential to be extended to 3d foams to produce a next generation of self - assembled disordered pbg materials, enabling fabrication of cheap and scalable photonic devices. | arxiv:1911.02443 |
we consider the dynamics and stationary regime of a capacitively - shunted transmon - type qubit in front of a mirror, affected by two signals : probe and dressing signals. by varying the parameters of these signals and then analyzing the probe signal ( reflected by the atom - mirror system ), it is possible to explore the system dynamics, which can be described by the bloch equation. the obtained time - dependent occupation probabilities are related to the experimentally measured reflection coefficient. the study of this type of dynamics opens up new horizons for better understanding of the system properties and underlying physical processes, such as landau - zener - stuckelberg - majorana transitions. | arxiv:2212.02545 |
we use f - theory to derive a general expression for the flux potential of type ii compactifications with d7 / d3 branes, including open string moduli and 2 - form fluxes on the branes. our main example is f - theory on k3 $ \ times $ k3 and its orientifold limit t ^ 2 / z _ 2 x k3. the full scalar potential cannot be derived from the bulk superpotential w = \ int \ omega \ wedge g _ 3 and generically destabilizes the orientifold. generically all open and closed string moduli are fixed, except for a volume factor. an alternative formulation of the problem in terms of the effective supergravity is given and we construct an explicit map between the f - theory fluxes and gaugings. we use the superpotential to compute the effective action for flux compactifications on orbifolds, including the \ mu - term and soft - breaking terms on the d7 - brane world - volume. | arxiv:hep-th/0501139 |
we consider a system where a waveguide is coupled to a cavity embedded with a two - level system ( tls ), and study the effects when a two - photon quantum state is injected into the waveguide. the wave function of two outgoing photons is exactly solved using the lehmann - symanzik - zimmermann ( lsz ) reduction formalism. our results explicitly exhibit the photon blockade effects in the strong atom - cavity coupling regime. the quantum statistical characters of the outgoing photons, including the photon bunching and anti - bunching behaviors, are also investigated in both the strong and weak coupling regimes. these results agree with the observations of recent experiments. | arxiv:1009.2828 |
in this paper, the connections are investigated between two different approaches towards the parametrization of multivariable stable all - pass systems in discrete - time. the first approach involves the tangential schur algorithm, which employs linear fractional transformations. it stems from the theory of reproducing kernel hilbert spaces and enables the direct construction of overlapping local parametrizations using schur parameters and interpolation points. the second approach proceeds in terms of state - space realizations. in the scalar case, a balanced canonical form exists that can also be parametrized by schur parameters. this canonical form can be constructed recursively, using unitary matrix operations. here, this procedure is generalized to the multivariable case by establishing the connections with the first approach. it gives rise to balanced realizations and overlapping canonical forms directly in terms of the parameters used in the tangential schur algorithm. | arxiv:1012.3272 |
in this paper, we show how behaviour trees ( bts ) can be used to design modular, versatile, and robust control architectures for mission - critical systems. in particular, we show this in the context of autonomous underwater vehicles ( auvs ). robustness, in terms of system safety, is important since manual recovery of auvs is often extremely difficult. further more, versatility is important to be able to execute many different kinds of missions. finally, modularity is needed to achieve a combination of robustness and versatility, as the complexity of a versatile systems needs to be encapsulated in modules, in order to create a simple overall structure enabling robustness analysis. the proposed design is illustrated using a typical auv mission. | arxiv:1811.00426 |
van der waals ( vdw ) interaction plays a fundamental role in the surface - molecules related phenomena. tuning of the correlated charge fluctuation in the vdw complex is a plausible way to modulate the molecules interaction at the atomic surface. we report vdw interaction tunability of the graphene - co $ _ 2 $ complex by combining the first principle calculations with the vdw exchange correlation density functionals and the time evaluation measurements of co $ _ 2 $ molecules adsorption / desorption on graphene under an external electric field. the field - dependent charge transfer within the complex unveils the controllable tuning of co $ _ 2 $ from acceptor to donor. meanwhile the configuration of the adsorbed molecule - the equilibrium distance from graphene and o - c - o bonding angle - is modified accordingly. the range of electrical tunability is a unique feature for each type of molecules. | arxiv:1507.01680 |
precision tests of the standard model and searches for new physics in the quark flavor sector depend on accurate theoretical calculations of decay rates and spectra for rare, flavor - changing processes. the theoretical status and recent developments of techniques allowing such calculations are reviewed. special attention is paid to the calculation of the b - > xs + gamma branching ratio, the extraction of the b - quark mass from a fit to b - > xc + l + nu moments, and the determination of | v ( ub ) | from spectra in the inclusive decay b - > xu + l + nu. from a reanalysis of different inclusive distributions the updated average value | v ( ub ) | = ( 3. 98 + - 0. 15 + - 0. 30 ) * 10 ^ { - 3 } is derived. using only the theoretically cleanest channels, we obtain | v ( ub ) | = ( 3. 70 + - 0. 15 + - 0. 28 ) * 10 ^ { - 3 }. | arxiv:0801.0675 |
we construct first - and second - order time discretization schemes for the cahn - hilliard - navier - stokes system based on the multiple scalar auxiliary variables approach ( msav ) approach for gradient systems and ( rotational ) pressure - correction for navier - stokes equations. these schemes are linear, fully decoupled, unconditionally energy stable, and only require solving a sequence of elliptic equations with constant coefficients at each time step. we carry out a rigorous error analysis for the first - order scheme, establishing optimal convergence rate for all relevant functions in different norms. we also provide numerical experiments to verify our theoretical results. | arxiv:2009.09353 |
microquasar stellar systems emit electromagnetic radiation and high - energy particles. thanks to their location within our own galaxy, they can be observed in high detail. still, many of their inner workings remain elusive ; hence, simulations, as the link between observations and theory, are highly useful. in this paper, both high - energy particle and synchrotron radio emissions from simulated microquasar jets are calculated using special relativistic imaging. a finite ray speed imaging algorithm is employed on hydrodynamic simulation data, producing synthetic images seen from a stationary observer. a hydrodynamical model is integrated in the above emission models. synthetic spectra and maps are then produced that can be compared to observations from detector arrays. as an application, the model synthetically observes microquasars during an episodic ejection at two different spatio - temporal scales : one on the neutrino emission region scale and the other on the synchrotron radio emission scale. the results are compared to the sensitivity of existing detectors. | arxiv:2311.07694 |
we present a review of our results for the masses and couplings of the scalar fully heavy four - quarks and $ t _ { qq \ bar { q } \ bar { q } ' } \, ( j ^ p = 0 ^ \ pm, 1 ^ \ pm ) $ tetraquarks states from qcd laplace sum rule ( lsr ), their ratios $ { \ cal r } $ and double ratio of sum rules ( drsr ) within stability criteria and including factorized next - to - leading order ( fnlo ) perturbative ( pt ) corrections. as the operator product expansion ( ope ) usually converges for $ d \ leqslant 6 - 8 $, we evaluated the qcd spectral functions at lowest order of pt qcd and up to $ \ langle g ^ 3 \ rangle $. our results for the $ 0 ^ { + + } $ fully heavy four - quark states may explain the lhcb broad structure around ( 6. 2 - 6. 7 ) gev which can be due to $ \ overline { \ eta _ c } \ eta _ c, ~ ~ \ overline { \ chi _ { c1 } } \ chi _ { c1 } $ and $ \ overline { j / \ psi } j / \ psi $ molecules or / and their analogue $ s _ c s _ c, ~ ~ a _ ca _ c $ and $ v _ cv _ c $ tetraquarks. the peak at ( 6. 8 - 6. 9 ) gev can be identified to the $ \ overline { \ chi _ { c0 } } \ chi _ { c0 } $ molecule or / and the $ p _ c p _ c $ tetraquark state. then, combining $ { \ cal r } $ and drsr we focus on the analysis of the four - quark nature of $ t _ { cc \ bar { q } \ bar { q } ' } $ $ 1 ^ { \ pm } $ and $ 0 ^ { \ pm } $ states. we show that combining $ { \ cal r } $ and drsr can provide more precise results : $ m _ { t ^ { 1 ^ + } _ { cc } } = 3886 ( 6 ) $ mev and $ m _ { t ^ { 0 ^ + } _ { cc } } = 3883 ( 3 ) $ mev. from our estimates of the masses of the pseudo | arxiv:2309.13547 |
we consider the one - armed bandit problem of woodroofe [ j. amer. statist. assoc. 74 ( 1979 ) 799 - - 806 ], which involves sequential sampling from two populations : one whose characteristics are known, and one which depends on an unknown parameter and incorporates a covariate. the goal is to maximize cumulative expected reward. we study this problem in a minimax setting, and develop rate - optimal polices that involve suitable modifications of the myopic rule. it is shown that the regret, as well as the rate of sampling from the inferior population, can be finite or grow at various rates with the time horizon of the problem, depending on " local " properties of the covariate distribution. proofs rely on martingale methods and information theoretic arguments. | arxiv:0909.0119 |
the belle ii detector at the superkekb accelerator complex is covering a wide range of exciting physics topics. to achieve the project ' s research goals, a substantial increase of the data sample to 50 ~ ab $ ^ { - 1 } $ is needed, and for that, the luminosity has to reach the ambitious goal of $ 6 \ times 10 ^ { 35 } $ cm $ ^ { - 2 } $ s $ ^ { - 1 } $. the progress towards the design luminosity is accompanied by research and development of the accelerator, detector components, operation methods, as well as their upgrades. in the present contribution, we will discuss the status and plans of the project, timescales for upgrades, their motivations, and opportunities, an overview of upgrade options, and finish with an outlook and perspectives. | arxiv:2211.13634 |
the dynamic density functional ( ddf ) theory and standard brownian dynamics simulations ( bds ) are used to study the drifting effects of a colloidal particle in a polymer solution, both for ideal and interacting polymers. the structure of the stationary density distributions and the total induced current are analyzed for different drifting rates. we find good agreement with the bds, which gives support to the assumptions of the ddf theory. the qualitative aspect of the density distribution are discussed and compared to recent results for driven colloids in one - dimensional channels and to analytical expansions for the ideal solution limit. | arxiv:cond-mat/0309586 |
it is widely believed that the parity of the partition function $ p ( n ) $ is ` ` random. ' ' contrary to this expectation, in this note we prove the existence of infinitely many congruence relations modulo 4 among its values. for each square - free integer $ 1 < d \ equiv 23 \ pmod { 24 }, $ we construct a weight 2 meromorphic modular form that is congruent modulo 4 to a certain twisted generating function for the numbers $ p \ big ( \ frac { dm ^ 2 + 1 } { 24 } \ big ) \ pmod 4 $. we prove the existence of infinitely many linear dependence congruences modulo 4 among suitable sets of holomorphic normalizations of these series. these results rely on the theory of class numbers and hilbert class polynomials, and { \ it generalized twisted borcherds products } developed by bruinier and the author. | arxiv:2212.06935 |
we study the entropy - corrected version of the new agegraphic dark energy ( nade ) model and dark matter in a spatially non - flat universe and in the framework of ho \ v { r } ava - lifshitz cosmology. for the two cases containing noninteracting and interacting entropy - corrected nade ( ecnade ) models, we derive the exact differential equation that determines the evolution of the ecnade density parameter. also the deceleration parameter is obtained. furthermore, using a parametrization of the equation of state parameter of the ecnade model as $ \ omega _ { \ lambda } ( z ) = \ omega _ 0 + \ omega _ 1 z $, we obtain both $ \ omega _ 0 $ and $ \ omega _ 1 $. we find that in the presence of interaction, the equation of state parameter $ \ omega _ 0 $ of this model can cross the phantom divide line which is compatible with the observation. | arxiv:1101.1774 |
the prototypical mira variable, $ o $ cet ( mira ), has been observed as a science verification target in the 2014 alma long baseline campaign with a longest baseline of 15 km. alma clearly resolves the images of the continuum and molecular line emission / absorption at an angular resolution of ~ 30 mas at 220 ghz. we image the data of the $ ^ { 28 } $ sio v = 0, 2 $ j $ = 5 - 4 and h $ _ 2 $ o $ \ nu _ 2 $ = 1 $ j ( k _ a, k _ c ) $ = 5 ( 5, 0 ) - 6 ( 4, 3 ) transitions and extract spectra from various lines - of - sight towards mira ' s extended atmosphere. in the course of imaging, we encountered ambiguities in the resulting images and spectra that appear to be related to the performance of the clean algorithm. we resolve mira ' s millimetre continuum emission and our data are consistent with a radio photosphere with a brightness temperature of 2611 $ \ pm $ 51 k, in agreement with recent results obtained with the vla. we do not confirm the existence of a compact region ( < 5 mas ) of enhanced brightness. we derive the gas density, kinetic temperature, molecular abundance and outflow / infall velocities in mira ' s extended atmosphere by modelling the sio and h $ _ 2 $ o lines. we find that sio - bearing gas starts to deplete beyond 4 $ r _ \ star $ and at a kinetic temperature of $ \ lesssim $ 600 k. the inner dust shells are probably composed of grain types other than pure silicates. during this observation, mira ' s atmosphere generally exhibited infall motion, with a shock front of velocity $ \ lesssim $ 12 km / s outside the radio photosphere. the structures predicted by the hydrodynamical model codex can reproduce the observed spectra in astonishing detail ; while some other models fail when confronted with the new data. combined with radiative transfer modelling, alma successfully demonstrates the ability to reveal the physical conditions of the extended atmospheres and inner winds of agb stars in unprecedented detail. ( abbreviated abstract ) | arxiv:1603.03371 |
we study random coloring of the hexagons of a honeycomb lattice into $ 2 ^ { n - 1 } $ colors ( that is the standard potts model at infinite temperature ). it may be considered as a generalization of percolation to $ n $ pairwise independent, but mutually dependent liquids. we introduce a new observable that can be interpreted as the fraction of percolated liquids. an analogue of the central limit theorem for this observable is proved and several conjectures based on numeric experiments are proposed. | arxiv:1908.11783 |
with the expanding application scope of unmanned aerial vehicles ( uavs ), the demand for stable uav control has significantly increased. however, in complex environments, gps signals are prone to interference, resulting in ineffective uav positioning. therefore, self - positioning of uavs in gps - denied environments has become a critical objective. some methods obtain geolocation information in gps - denied environments by matching ground objects in the uav viewpoint with remote sensing images. however, most of these methods only provide coarse - level positioning, which satisfies cross - view geo - localization but cannot support precise uav positioning tasks. consequently, this paper focuses on a newer and more challenging task : precise uav self - positioning based on remote sensing images. this approach not only considers the features of ground objects but also accounts for the spatial distribution of objects in the images. to address this challenge, we present a deep learning framework with geographic information adaptive loss, which achieves precise localization by aligning uav images with corresponding satellite imagery in fine detail through the integration of geographic information from multiple perspectives. to validate the effectiveness of the proposed method, we conducted a series of experiments. the results demonstrate the method ' s efficacy in enabling uavs to achieve precise self - positioning using remote sensing imagery. | arxiv:2502.16164 |
curriculum across the educational service area. in 2011, unesco started a yearly symposium called mobile learning week with the purpose of gathering stakeholders to discuss the m - learning initiative. implementation is not without its challenges. while mobile phone and internet use are increasing much more rapidly in sub - saharan africa than in other developing countries, the progress is still slow compared to the rest of the developed world, with smartphone penetration only expected to reach 20 % by 2017. additionally, there are gender, social, and geo - political barriers to educational access, and the severity of these barriers vary greatly by country. overall, 29. 6 million children in sub - saharan africa were not in school in the year 2012, owing not just to the geographical divide, but also to political instability, the importance of social origins, social structure, and gender inequality. once in school, students also face barriers to quality education, such as teacher competency, training and preparedness, access to educational materials, and lack of information management. = = = = growth in modern society and developing countries = = = = in modern society, ict is ever - present, with over three billion people having access to the internet. with approximately 8 out of 10 internet users owning a smartphone, information and data are increasing by leaps and bounds. this rapid growth, especially in developing countries, has led ict to become a keystone of everyday life, in which life without some facet of technology renders most of clerical, work and routine tasks dysfunctional. the most recent authoritative data, released in 2014, shows " that internet use continues to grow steadily, at 6. 6 % globally in 2014 ( 3. 3 % in developed countries, 8. 7 % in the developing world ) ; the number of internet users in developing countries has doubled in five years ( 2009 – 2014 ), with two - thirds of all people online now living in the developing world. " = = = = limitations = = = = however, hurdles are still large. " of the 4. 3 billion people not yet using the internet, 90 % live in developing countries. in the world ' s 42 least connected countries ( lccs ), which are home to 2. 5 billion people, access to icts remains largely out of reach, particularly for these countries ' large rural populations. " ict has yet to penetrate the remote areas of some countries, with many developing countries dearth of any type of internet. this also includes the availability of telephone lines, particularly the availability of cellular coverage, and other forms of electronic transmission of data. the latest | https://en.wikipedia.org/wiki/Information_and_communications_technology |
let $ k $ be an algebraically closed field of positive characteristic $ p $. we describe the full lattice of subfunctors of the diagonal $ p $ - permutation functor $ kr _ k $ obtained by $ k $ - linear extension from the functor $ r _ k $ of linear representations over $ k $. this leads to the description of the ` ` composition factors ' ' $ s _ p $ of $ kr _ k $, which are parametrized by finite $ p $ - groups ( up to isomorphism ), and of the evaluations of these particular simple diagonal $ p $ - permutation functors over $ k $. | arxiv:2412.04221 |
in this paper, we present some new nonexistence results on $ ( m, n ) $ - generalized bent functions, which improved recent results. more precisely, we derive new nonexistence results for general $ n $ and $ m $ odd or $ m \ equiv 2 \ pmod { 4 } $, and further explicitly prove nonexistence of $ ( m, 3 ) $ - generalized bent functions for all integers $ m $ odd or $ m \ equiv 2 \ pmod { 4 } $. the main tools we utilized are certain exponents of minimal vanishing sums from applying characters to group ring equations that characterize $ ( m, n ) $ - generalized bent functions. | arxiv:1908.00842 |
there exists a paradigm in which quantum mechanics is an exclusively developed theory to explain phenomena on a microscopic scale. as the planck ' s constant is extremely small, $ h \ sim10 ^ { - 34 } { j. s } $, and as in the relation of de broglie the wavelength is inversely proportional to the momentum ; for a mesoscopic or macroscopic object the broglie wavelength is very small, and consequently the undulatory behavior of this object is undetectable. in this paper we show that with a particle oscillating around its classical trajectory, the action is an integer multiple of a quantum of action, $ s = nh _ { o } $. the quantum of action, $ h _ { o } $, which plays a role equivalent to planck ' s constant, is a free parameter that must be determined and depends on the physical system considered. for a mesoscopic and macroscopic system : $ h _ { o } \ gg h $, this allows us to describe these systems with the formalism of quantum mechanics. | arxiv:1202.1876 |
based on bethe - ansatz approach and inelastic neutron scattering experiments, we reveal evolution of confinement of many - body bethe strings in ordered regions of quasi - one - dimensional antiferromagnet $ \ rm ybalo _ 3 $. in the antiferromagnetic phase, the spin dynamics is dominated by the confined length - 1 bethe strings, whose dominancy in the high - energy branch of the excitation spectrum yields to the confined length - 2 bethe strings when the material is tuned to the spin - density - wave phase. in the thermal - induced disordered region, the confinement effect disappears, and the system restores the conventional quantum integrable physics of the one - dimensional heisenberg model. our results establish a unified picture based on bethe string for the spin dynamics in different magnetic phases of $ \ rm ybalo _ 3 $, and thus provide profound insight into the many - body quantum magnetism. | arxiv:2212.03442 |
the quantum battery ( qb ) makes use of quantum effects to store and supply energy, which may outperform its classical counterpart. however, there are two challenges in this field. one is that the environment - induced decoherence causes the energy loss and aging of the qb, the other is that the decreasing of the charger - qb coupling strength with increasing their distance makes the charging of the qb become inefficient. here, we propose a qb scheme to realize a remote charging via coupling the qb and the charger to a rectangular hollow metal waveguide. it is found that an ideal charging is realized as long as two bound states are formed in the energy spectrum of the total system consisting of the qb, the charger, and the electromagnetic environment in the waveguide. using the constructive role of the decoherence, our qb is immune to the aging. additionally, without resorting to the direct charger - qb interaction, our scheme works in a way of long - range and wireless - like charging. effectively overcoming the two challenges, our result supplies an insightful guideline to the practical realization of the qb by reservoir engineering. | arxiv:2308.13784 |
we report a precise determination of the lifetime of the ( 4p ) $ ^ 2 $ p $ _ { 3 / 2 } $ state of $ ^ { 40 } $ ca $ ^ + $, $ \ tau _ { \ textrm { p } _ { 3 / 2 } } = 6. 639 ( 42 ) $ ns, using a combination of measurements of the induced light shift and scattering rate on a single trapped ion. good agreement with the result of a recent high - level theoretical calculation, $ 6. 69 ( 6 ) $ ns [ safronova et al., pra 83, 012503 ( 2011 ) ], but a 6 - $ \ sigma $ discrepancy with the most precise previous experimental value, $ 6. 924 ( 19 ) $ ns [ jin et al., prl 70, 3213 ( 1993 ) ] is found. to corroborate the consistency and accuracy of the new measurements, relativistically corrected ratios of reduced - dipole - matrix elements are used to directly compare our result with a recent result for the p $ _ { 1 / 2 } $ state, yielding a good agreement. the application of the present method to precise determinations of radiative quantities of molecular systems is discussed. | arxiv:1909.10516 |
stochastic approximation ( sa ) algorithms have been widely applied in minimization problems when the loss functions and / or the gradient information are only accessible through noisy evaluations. stochastic gradient ( sg ) descent - - - a first - order algorithm and a workhorse of much machine learning - - - is perhaps the most famous form of sa. among all sa algorithms, the second - order simultaneous perturbation stochastic approximation ( 2spsa ) and the second - order stochastic gradient ( 2sg ) are particularly efficient in handling high - dimensional problems, covering both gradient - free and gradient - based scenarios. however, due to the necessary matrix operations, the per - iteration floating - point - operations ( flops ) cost of the standard 2spsa / 2sg is $ o ( p ^ 3 ) $, where $ p $ is the dimension of the underlying parameter. note that the $ o ( p ^ 3 ) $ flops cost is distinct from the classical spsa - based per - iteration $ o ( 1 ) $ cost in terms of the number of noisy function evaluations. in this work, we propose a technique to efficiently implement the 2spsa / 2sg algorithms via the symmetric indefinite matrix factorization and show that the flops cost is reduced from $ o ( p ^ 3 ) $ to $ o ( p ^ 2 ) $. the formal almost sure convergence and rate of convergence for the newly proposed approach are directly inherited from the standard 2spsa / 2sg. the improvement in efficiency and numerical stability is demonstrated in two numerical studies. | arxiv:1906.09533 |
closed expressions are derived for resonant multidimensional x - ray spectroscopy using the quasiparticle nonlinear exciton representation of optical response. this formalism is applied to predict coherent four wave mixing signals which probe single and two core - hole states. nonlinear x - ray signals are compactly expressed in terms of one - and two - particle green ' s functions which can be obtained from the solution of hedin - like equations at the $ gw $ level. | arxiv:0906.0551 |
in this article we consider one - dimensional random systems of hyperbolic conservation laws. we first establish existence and uniqueness of random entropy admissible solutions for initial value problems of conservation laws which involve random initial data and random flux functions. based on these results we present an a posteriori error analysis for a numerical approximation of the random entropy admissible solution. for the stochastic discretization, we consider a non - intrusive approach, the stochastic collocation method. the spatio - temporal discretization relies on the runge - - kutta discontinuous galerkin method. we derive the a posteriori estimator using continuous reconstructions of the discrete solution. combined with the relative entropy stability framework this yields computable error bounds for the entire space - stochastic discretization error. the estimator admits a splitting into a stochastic and a deterministic ( space - time ) part, allowing for a novel residual - based space - stochastic adaptive mesh refinement algorithm. we conclude with various numerical examples investigating the scaling properties of the residuals and illustrating the efficiency of the proposed adaptive algorithm. | arxiv:1902.05375 |
the nonlinear optical ( nlo ) properties of 1 - ( 4 - methyl ) - piperazinylfullerene [ 60 ] ( mpf ) incorporated with a polysiloxane copolymer denoted as psi - 46 have been studied using nanosecond laser pulses at 532 - nm wavelength. the optical limiting performance of mpf itself is poorer than that of its parent c60, while the contribution of psi - 46 attached to the mpf shows marginally improvement from the ratio of mpf / psi - 46 ( 1 : 2 ) to mpf / psi - 46 ( 1 : 6 ). however, the effect can be neglected to the mpf optical limiting responses. the photoluminescence emission of mpf - containing polymers was slightly improved in comparison with that of mpf. the possible sources for the slightly improvement in the nlo behaviour are discussed. | arxiv:cond-mat/0302463 |
machine learning algorithms based on brain - inspired hyperdimensional ( hd ) computing imitate cognition by exploiting statistical properties of high - dimensional vector spaces. it is a promising solution for achieving high energy efficiency in different machine learning tasks, such as classification, semi - supervised learning, and clustering. a weakness of existing hd computing - based ml algorithms is the fact that they have to be binarized to achieve very high energy efficiency. at the same time, binarized models reach lower classification accuracies. to solve the problem of the trade - off between energy efficiency and classification accuracy, we propose the qubithd algorithm. it stochastically binarizes hd - based algorithms, while maintaining comparable classification accuracies to their non - binarized counterparts. the fpga implementation of qubithd provides a 65 % improvement in terms of energy efficiency, and a 95 % improvement in terms of training time, as compared to state - of - the - art hd - based ml algorithms. it also outperforms state - of - the - art low - cost classifiers ( such as binarized neural networks ) in terms of speed and energy efficiency by an order of magnitude during training and inference. | arxiv:1911.12446 |
in this first of a two - paper sequence, we report techniques and results of the cornell high - order adaptive optics survey for brown dwarf companions ( chaos ). at the time of this writing, this study represents the most sensitive published population survey of brown dwarf companions to main sequence stars, for separation akin to our own outer solar system. the survey, conducted using the palomar 200 - inch hale telescope, consists of k - short coronagraphic observations of 80 main sequence stars out to 22 parsecs. at 1 arcsecond separations from a typical target system, the survey achieves median sensitivities 10 magnitudes fainter than the parent star. in terms of companion mass, the survey achieves typical sensitivities of 25 jupiter masses ( 1 gyr ), 50 jupiter masses ( solar age ), and 60 jupiter masses ( 10 gyr ), using evolutionary models of baraffe et al. ( 2003 ). using common proper motion to distinguish companions from field stars, we find that no systems show positive evidence of a substellar companion ( searchable separation 1 - 15 arcseconds [ projected separation ~ 10 - 155 au at the median target distance ] ). in the second paper of the series we shall present our monte carlo population simulations. | arxiv:astro-ph/0506287 |
with an average eccentricity of about 0. 29, the eccentricity distribution of extrasolar planets is markedly different from the solar system. among other scenarios considered, it has been proposed that eccentricity may grow through planet - disc interaction. recently, it has been noticed that the thermodynamical state of the disc can significantly influence the migration properties of growing protoplanets. however, the evolution of planetary eccentricity in radiative discs has not been considered yet. in this paper we study the evolution of planets on eccentric orbits that are embedded in a three - dimensional viscous disc and analyse the disc ' s effect on the orbital evolution of the planet. we use the three - dimensional hydrodynamical code nirvana that includes full tensor viscosity and implicit radiation transport in the flux - limited diffusion approximation. the code uses the fargo - algorithm to speed up the simulations. first we measure the torque and power exerted on the planet by the disc for fixed orbits, and then we let the planet start with initial eccentricity and evolve it in the disc. for locally isothermal we confirm previous results and find eccentricity damping and inward migration for planetary cores. in the case of radiative discs, the planets experience an inward migration as long as its eccentricity lies above a certain threshold. after the damping of eccentricity cores with masses below 33 earthmasses begin to migrate outward in radiative discs, while higher mass cores always migrate inward. for all planetary masses studied ( up to 200 earthmasses ) we find eccentricity damping. in viscous discs the orbital eccentricity of embedded planets is damped during the evolution independent of the mass. hence, planet - disc interaction does not seem to be a viable mechanism to explain the observed high eccentricity of exoplanets. | arxiv:1008.2656 |
we study the locc - assisted quantum capacity of bosonic dephasing channel with energy constraint on input states. we start our analysis by focusing on the energy - constrained squashed entanglement of the channel, which is an upper bound for the energy - constrained locc - assisted quantum capacity. as computing energy - constrained squashed entanglement of the channel is challenging due to a double optimization ( over the set of density matrices and the isometric extensions of a squashing channel ), we first derive an upper bound for it, and then we discuss how tight that bound is for energy - constrained locc - assisted quantum capacity of bosonic dephasing channel. we prove that the optimal input state is diagonal in the fock basis. furthermore, we prove that for a generic channel, the optimal squashing channel belongs to the set of symmetric quantum markov chain inducer ( sqmci ) channels of the channel system - environment output, provided that such a set is non - empty. with supporting arguments, we conjecture that this is instead the case for the bosonic dephasing channel. hence, for it we analyze two explicit examples of squashing channels which are not sqmci, but are symmetric. through them, we derive explicit upper and lower bounds for the energy - constrained locc - assisted quantum capacity of the bosonic dephasing channel in terms of its quantum capacity with different noise parameters. as the difference between upper and lower bounds is at most of the order $ 10 ^ { - 1 } $, we conclude that the bounds are tight. hence we provide a very good estimation of the locc - assisted quantum capacity of the bosonic dephasing channel. | arxiv:2111.04173 |
the production of electrons from beauty - hadron decays was measured at midrapidity in proton - proton ( pp ) and central pb - pb collisions at center - of - mass energy per nucleon - nucleon pair $ \ sqrt { s _ { \ rm nn } } $ = 5. 02 tev, using the alice detector at the lhc. the cross section measured in pp collisions in the transverse momentum interval $ 2 < p _ { \ rm t } < 8 $ gev / $ c $ was compared with models based on perturbative quantum chromodynamics calculations. the yield in the 10 % most central pb - pb collisions, measured in the interval $ 2 < p _ { \ rm t } < 26 $ gev / $ c $, was used to compute the nuclear modification factor $ r _ { \ rm aa } $, extrapolating the pp reference cross section to $ p _ { \ rm t } $ larger than 8 gev / $ c $. the measured $ r _ { \ rm aa } $ shows significant suppression of the yield of electrons from beauty - hadron decays at high $ p _ { \ rm t } $ and does not show a significant dependence on $ p _ { \ rm t } $ above 8 gev / $ c $ within uncertainties. the results are described by several theoretical models based on different implementations of the interaction of heavy quarks with a quark - gluon plasma, which predict a smaller energy loss for beauty quarks compared to light and charm quarks. | arxiv:2211.13985 |
dispersionless ( flat ) electronic bands are investigated regarding their conductance properties. due to " caging " of carriers these bands are usually insulating at partial filling, at least on the non - interacting level. considering the specific example of a $ \ mathcal { t } _ 3 $ - - lattice we study long - range coulomb interactions. a non - trivial dependence of the conductivity on flat band filling is obtained, exhibiting an infinite number of zeros. near these zeros, the conductivity rises linearly with carrier density. at densities half way in between adjacent conductivity - zeros, strongly enhanced conductivity is predicted, accompanying a solid - solid phase transition. | arxiv:1407.6286 |
inversion symmetry breaking and spin - orbit coupling lead to valley and spin hall effect in mos2. because of the large valley separation in momentum space, the valley index is expected to be robust. in this paper, quantum hall effect in mos2 originated from berry curvature is analyzed after review of symmetry structure and spin - orbit coupling hamiltonian of mos2. finally an expression and rough calculation is given for valley and spin hall effect. | arxiv:1803.05325 |
we report on visible light emission from si - nanocrystal based optically active microdisk resonators. the room temperature photoluminescence ( pl ) from single microdisks shows the characteristic modal structure of whispering - gallery modes. the emission is both te and tm - polarized in 300 nm thick microdisks, while thinner ones ( 135 nm ) support only te - like modes. thinner disks have the advantage to filter out higher order radial mode families, allowing for measuring only the most intense first order modal structure. we reveal subnanometer linewidths and corresponding quality factors as high as 2800, limited by the spectral resolution of the experimental setup. moreover, we observe a modification of mode linewidth by a factor 13 as a function of pump power. the origin of this effect is attributed to an excited carrier absorption loss mechanism. | arxiv:0806.1128 |
we study cosmology on a bps d3 - brane evolving in the 10d sugra background describing a non - bps brane. initially the bps brane is taken to be a probe whose dynamics we determine in the non - compact non - bps background. the cosmology observed on the brane is of the frw type with a scale factor $ s ( \ tau ) $. in this mirage cosmology approach, there is no self - gravity on the brane which cannot inflate. self - gravity is then included by compactifying the background space - time. the low energy effective theory below the compactification scale is shown to be bi - metric, with matter coupling to a different metric than the geometrically induced metric on the brane. the geometrical scale factor on the brane is now $ s ( \ tau ) a ( \ tau ) $ where $ a ( \ tau ) $ arises from brane self - gravity. in this non - bps scenario the brane generically inflates. we study the resulting inflationary scenario taking into account the fact that the non - bps brane eventually decays on a time - scale much larger than the typical inflationary time - scale. after the decay, the theory ceases to be bi - metric and cobe normalization is used to estimate the string scale which is found to be of order $ 10 ^ { 14 } $ gev. | arxiv:hep-th/0204120 |
we derive an integro - differential equation for propagation of cosmological gravitation waves in spatially closed cosmology whereas the traceless transverse tensor part of the anisotropic stress tensor is free streaming neutrinos ( including antineutrinos ), which have been traveling essentially without collision since temperature dropped below about $ 10 ^ { 10 } k $. we studied the short wavelengths and long wavelengths of gravitational waves ( gws ) that enter the horizon in closed spacetime. the solution shows that the anisotropic stress reduces the squared amplitude by 76 % for wavelengths that enter the horizon during radiation - dominated phase and this reduction is less for the wavelength that enter the horizon at later times. at the end we compare the results to the | arxiv:1409.6958 |
the radiative decay of the massive neutrino $ \ nu _ i \ rightarrow \ nu _ j \ gamma $ is investigated in the framework of the standard model in external electromagnetic fields of various configurations : constant crossed field, constant uniform magnetic field, plane monochromatic wave ' s field. the effect of significant enhancement of the neutrino decay probability by the external field ( electromagnetic catalysis ) is discussed. an especially strong enhancement occurs in the case of the ultrarelativistic neutrino decay, since in this case the decay probability does not contain suppression caused by the smallness of the decaying neutrino mass. the ultrarelativistic neutrino decay catalysis is significant even in a relatively weak external field ( $ f / f _ e < < 1 $, where $ f _ e $ is the critical schwinger value ). the expression for the photon splitting probability into the neutrino pair $ \ gamma \ rightarrow \ nu _ i \ bar \ nu _ j $ in the wave field is given. the estimations of a number of gamma - quanta produced in a volume filled with an electromagnetic field and the neutrino lifetime in a strong magnetic field are presented. | arxiv:hep-ph/9610219 |
we explore the possibility of using amplitude and phase fluctuations of gravitational waves due to gravitational lensing as a probe of the small - scale matter power spectrum. the direct measurement of the small - scale matter power spectrum is made possible by making use of the frequency dependence of such gravitational lensing dispersions originating from the wave optics nature of the propagation of gravitational waves. we first study the small - scale behavior of the matter power spectrum in detail taking the so - called halo model approach including effects of baryons and subhalos. we find that the matter power spectrum at the wavenumber $ k \ sim 10 ^ 6h { \ rm mpc } ^ { - 1 } $ is mainly determined by the abundance of dark low - mass halos with mass $ 1h ^ { - 1 } m _ \ odot \ lesssim m \ lesssim 10 ^ 4h ^ { - 1 } m _ \ odot $ and is relatively insensitive to baryonic effects. the matter power spectrum at this wavenumber is probed by gravitational lensing dispersions of gravitational waves at frequencies of $ f \ sim 0. 1 - 1 $ ~ hz with predicted signals of $ \ mathcal { o } ( 10 ^ { - 3 } ) $. we also find that primordial black holes ( pbhs ) with $ m _ { \ rm pbh } \ gtrsim 0. 1 ~ m _ \ odot $ can significantly enhance the matter power spectrum at $ k \ gtrsim 10 ^ 5h { \ rm mpc } ^ { - 1 } $ due to both the enhanced halo formation and the shot noise from pbhs. we find that gravitational lensing dispersions at $ f \ sim 10 - 100 $ ~ hz are particularly sensitive to pbhs and can be enhanced by more than an order of magnitude depending on the mass and abundance of pbhs. | arxiv:2007.01936 |
we present a study of binary mixtures of bose - einstein condensates confined in a double - well potential within the framework of the mean field gross - pitaevskii equation. we reexamine both the single component and the binary mixture cases for such a potential, and we investigate in which situations a simpler two - mode approach leads to an accurate description of their dynamics. we also estimate the validity of the most usual dimensionality reductions used to solve the gross - pitaevskii equations. to this end, we compare both the semi - analytical two - mode approaches and the numerical simulations of the 1d reductions with the full 3d numerical solutions of the gross - pitaevskii equation. our analysis provides a guide to clarify the validity of several simplified models that describe mean field non - linear dynamics, using an experimentally feasible binary mixture of an f = 1 spinor condensate with two of its zeeman manifolds populated, m = + 1 and m = - 1. | arxiv:1005.5272 |
we experimentally investigate spectral statistics in anderson localization in two - dimensional amorphous disordered media. intensity distributions captured over an ultrabroad wavelength range of $ \ sim 600 $ ~ nm and averaged over numerous configurations provided the ioffe - regel parameter to be $ \ sim2. 5 $ over the investigated wavelength range. the spectra of the disordered structures provided access to several quasimodes, whose widths and separations allowed to directly estimate the optical thouless conductance $ g _ { th } $, consistently observed to be below unity. the probability distribution of $ g _ { th } $ was measured to be a log - normal. despite being in the anderson localization regime, the spacings of energy levels of the system was seen to follow a near wigner - dyson function. theoretical calculations based on the tight - binding model, modified to include coupling to a bath, yielded results that were in excellent agreement with experiments. from the model, the level - spacing behavior was attributed to the degree of localization obtained in the optical disordered system. | arxiv:1910.14451 |
we give another proof that $ m $ - dissimilarity vectors of weighted trees are points on the tropical grassmanian, as conjectured by cools, and proved by giraldo in response to a question of sturmfels and pachter. we accomplish this by relating $ m $ - dissimilarity vectors to the representation theory of $ sl _ m. $ | arxiv:1003.3970 |
many psychologists do not realize that exploratory use of the popular multiway analysis of variance ( anova ) harbors a multiple comparison problem. in the case of two factors, three separate null hypotheses are subject to test ( i. e., two main effects and one interaction ). consequently, the probability of at least one type i error ( if all null hypotheses are true ) is 14 % rather than 5 % if the three tests are independent. we explain the multiple comparison problem and demonstrate that researchers almost never correct for it. to mitigate the problem, we describe four remedies : the omnibus f test, the control of familywise error rate, the control of false discovery rate, and the preregistration of hypotheses. | arxiv:1412.3416 |
hayes equivalence is defined on monic polynomials over a finite field $ \ fq $ in terms of the prescribed leading coefficients and the residue classes modulo a given monic polynomial $ q $. we study the distribution of the number of zeros in a random polynomial over finite fields in a given hayes equivalence class. it is well known that the number of distinct zeros of a random polynomial over $ \ fq $ is asymptotically poisson with mean 1. we show that this is also true for random polynomials in any given hayes equivalence class. asymptotic formulas are also given for the number of such polynomials when the degree of such polynomials is proportional to $ q $ and the degree of $ q $ and the number of prescribed leading coefficients are bounded by $ \ sqrt { q } $. when $ q = 1 $, the problem is equivalent to the study of the distance distribution in reed - solomon codes. our asymptotic formulas extend some earlier results and imply that all words for a large family of reed - solomon codes are ordinary, which further supports the well - known { \ em deep - hole } conjecture. | arxiv:2203.06729 |
a set $ s $ of permutations is forcing if for any sequence $ \ { \ pi _ i \ } _ { i \ in \ mathbb { n } } $ of permutations where the density $ d ( \ pi, \ pi _ i ) $ converges to $ \ frac { 1 } { | \ pi |! } $ for every permutation $ \ pi \ in s $, it holds that $ \ { \ pi _ i \ } _ { i \ in \ mathbb { n } } $ is quasirandom. graham asked whether there exists an integer $ k $ such that the set of all permutations of order $ k $ is forcing ; this has been shown to be true for any $ k \ ge 4 $. in particular, the set of all twenty - four permutations of order $ 4 $ is forcing. we provide the first non - trivial lower bound on the size of a forcing set of permutations : every forcing set of permutations ( with arbitrary orders ) contains at least four permutations. | arxiv:2011.09434 |
we study the effect of thermal blurring caused by the use of ( momentum - space ) rapidity as a proxy of coordinate - space rapidity in experimental measurements of conserved charge fluctuations in relativistic heavy ion collisions. in theoretical studies assuming statistical mechanics, calculated fluctuations are those in a spatial volume. experiments, on the other hand, can measure fluctuations only in a momentum - space in the final state. in a standard argument to compare experimental results for a momentum space with theoretical studies for a coordinate space, rapidities of particles are implicitly regarded as equivalent to their coordinate - space rapidity. we show that the relation of two fluctuations is significantly altered by the existence of the thermal motion, i. e. thermal blurring. we discuss that the thermal blurring can be regarded as a part of the diffusion process, and the effect can be understood by studying the rapidity window dependences of fluctuations. centrality dependence of the thermal blurring effect is also discussed. | arxiv:1606.03827 |
we introduce the transformed generative pre - trained physics - informed neural networks ( tgpt - pinn ) for accomplishing nonlinear model order reduction ( mor ) of transport - dominated partial differential equations in an mor - integrating pinns framework. building on the recent development of the gpt - pinn that is a network - of - networks design achieving snapshot - based model reduction, we design and test a novel paradigm for nonlinear model reduction that can effectively tackle problems with parameter - dependent discontinuities. through incorporation of a shock - capturing loss function component as well as a parameter - dependent transform layer, the tgpt - pinn overcomes the limitations of linear model reduction in the transport - dominated regime. we demonstrate this new capability for nonlinear model reduction in the pinns framework by several nontrivial parametric partial differential equations. | arxiv:2403.03459 |
there are ongoing efforts in detecting hawking radiation from primordial black holes ( pbh ) formed during the early universe. here we put an upper limit on the pbh number density that could have been formed prior to the big bang nucleosynthesis era, based on the constraint that the pbh evaporation energy consisting of high energy radiation not affect the observed abundances ' of elements, by disintegrating the nuclei. | arxiv:1006.5342 |
in this paper we study the coleman - oort conjecture for superelliptic curves, i. e., curves defined by affine equations $ y ^ n = f ( x ) $ with $ f $ a separable polynomial. we prove that up to isomorphism there are at most finitely many superelliptic curves of fixed genus $ g \ geq 8 $ with cm jacobians. the proof relies on the geometric structures of shimura subvarieties in siegel modular varieties and the stability properties of higgs bundles associated to fibred surfaces. | arxiv:1611.08477 |
the $ t _ z $ ~ = ~ $ - \ frac { 3 } { 2 } $ nucleus $ { } ^ { 21 } $ mg has been studied by coulomb excitation on $ { } ^ { 196 } $ pt and $ { } ^ { 110 } $ pd targets. a 205. 6 ( 1 ) - kev $ \ gamma $ - ray transition resulting from the coulomb excitation of the $ \ frac { 5 } { 2 } ^ + $ ground state to the first excited $ \ frac { 1 } { 2 } ^ + $ state in $ { } ^ { 21 } $ mg was observed for the first time. coulomb excitation cross - section measurements with both targets and a measurement of the half - life of the $ \ frac { 1 } { 2 } ^ + $ state yield an adopted value of $ b ( e2 ; \ frac { 5 } { 2 } ^ + \ rightarrow \ frac { 1 } { 2 } ^ + ) $ ~ = ~ 13. 3 ( 4 ) ~ w. u. a new excited state at 1672 ( 1 ) ~ kev with tentative $ \ frac { 9 } { 2 } ^ + $ assignment was also identified in $ { } ^ { 21 } $ mg. this work demonstrates large difference of the $ b ( e2 ; \ frac { 5 } { 2 } ^ + \ rightarrow \ frac { 1 } { 2 } ^ + ) $ values between $ t $ ~ = ~ $ \ frac { 3 } { 2 } $, $ a $ ~ = ~ 21 mirror nuclei. the difference is investigated in the shell - model framework employing both isospin conserving and breaking usd interactions and using modern \ textsl { ab initio } nuclear structure calculations, which have recently become applicable in the $ sd $ shell. | arxiv:1811.00774 |
a finite - dimensional su ( $ n $ ) lie algebra equation is discussed that in the infinite $ n $ limit ( giving the area preserving diffeomorphism group ) tends to the two - dimensional, inviscid vorticity equation on the torus. the equation is numerically integrated, for various values of $ n $, and the time evolution of an ( interpolated ) stream function is compared with that obtained from a simple mode truncation of the continuum equation. the time averaged vorticity moments and correlation functions are compared with canonical ensemble averages. | arxiv:hep-th/9206025 |
these lectures address the effects of cosmic rays over macro - instabilities which develop in the interstellar medium and the micro - instabilities the particles are able to trigger themselves. the lectures are centered on the derivation of linear growth rates but also discuss some numerical simulations addressing the issue of magnetic field saturation. a particular emphasis is made on the streaming instability, an instability driven by anisotropic cosmic - ray distributions. | arxiv:2312.17134 |
we study the dynamics of the discrete nonlinear schr { \ " o } dinger lattice initialized such that a very long transitory period of time in which standard boltzmann statistics is insufficient is reached. our study of the nonlinear system locked in this { \ em non - gibbsian } state focuses on the dynamics of discrete breathers ( also called intrinsic localized modes ). it is found that part of the energy spontaneously condenses into several discrete breathers. although these discrete breathers are extremely long lived, their total number is found to decrease as the evolution progresses. even though the total number of discrete breathers decreases we report the surprising observation that the energy content in the discrete breather population increases. we interpret these observations in the perspective of discrete breather creation and annihilation and find that the death of a discrete breather cause effective energy transfer to a spatially nearby discrete breather. it is found that the concepts of a multi - frequency discrete breather and of internal modes is crucial for this process. finally, we find that the existence of a discrete breather tends to soften the lattice in its immediate neighborhood, resulting in high amplitude thermal fluctuation close to an existing discrete breather. this in turn nucleates discrete breather creation close to a already existing discrete breather. | arxiv:patt-sol/9901002 |
searching for exotic interactions provides a path for exploring new particles beyond the standard model. here, we used an ensemble - nv - diamond magnetometer to search for an exotic spin - and velocity - dependent interaction between polarized electron spins and unpolarized nucleons at the micrometer scale. a thin layer of nitrogen - vacancy electronic spin ensemble in diamond is utilized as both the solid - state spin quantum sensor and the polarized electron source, and a vibrating lead sphere serves as the moving unpolarized nucleon source. the exotic interaction is searched by detecting the possible effective magnetic field induced by the moving unpolarized nucleon source using the ensemble - nv - diamond magnetometer. our result establishes new bounds for the coupling parameter $ f _ \ perp $ within the force range from 5 to 400 $ \ rm \ mu $ m. the upper limit of the coupling parameter at 100 $ \ rm \ mu $ m is $ \ lvert f _ \ perp \ rvert \ leq 1. 1 \ times 10 ^ { - 11 } $, which is 3 orders of magnitude more stringent than the previous constraint. this result shows that nv ensemble can be a promising platform to search for hypothetical particles beyond the standard model. | arxiv:2308.02254 |
we report new results for lattice gauge theories with twelve fermion flavors in the fundamental representation and two fermion flavors in the two - index symmetric ( sextet ) representation of the su ( 3 ) color gauge group. both models are important in searching for a viable composite higgs mechanism in the beyond the standard model ( bsm ) paradigm. we subject both models to opposite hypotheses inside and outside of the conformal window. in the first hypothesis we test chiral symmetry breaking ( $ \ chi { \ rm sb } $ ) with its goldstone spectrum, $ f _ \ pi $, the $ \ chi { \ rm sb } $ condensate, and several composite hadron states as the fermion mass is varied in a limited range with our best effort to control finite volume effects. supporting results for $ \ chi { \ rm sb } $ from the running coupling based on the force between static sources is also presented. in the second test for the alternate hypothesis we probe conformal behavior driven by a single anomalous mass dimension under the assumption of unbroken chiral symmetry. our results show very low level of confidence in the conformal scenario. | arxiv:1103.5998 |
effective field theory is an effective approach to parameterizing effects of high energy scale physics in low energy measurements. the two popular frameworks for physics beyond the standard model are the so - called standard model effective field theory ( smeft ) and the higgs effective field theory ( heft ). while the description by the smeft deteriorates when the scale of new physics is not so high or it participates in spontaneous electroweak symmetry breaking, the heft makes use of nonlinear realization of spontaneously broken symmetry in which there are practically no restrictions on the higgs field as a singlet. in this work we present another framework, called broken phase effective field theory ( beft ), in which we deal directly with mass eigenstate fields after spontaneous symmetry breaking without employing nonlinear realization. we take the type - ii seesaw model as an example to demonstrate our approach. by matching the model to both the beft and the smeft at tree level, we compare the results for two processes, the higgs pair production via vector boson fusion which appears as a subprocess at the lhc and the higgs - strahlung process at a future electron - positron collider. we find that the beft reproduces the type - ii seesaw model more accurately than the smeft in the regions where the bare mass of the higgs triplet becomes close to the electroweak scale. therefore, the beft serves as a useful framework that can compensate for the shortcomings in both the smeft and the heft when dealing with uv models that involve higgs mixing or new particles with a mass close to the electroweak scale. | arxiv:2504.02580 |
the recent availability of wideband receivers and high sensitivity instruments in the mm and submm wavelengths has opened the possibility of studying in detail the chemistry of the interstellar medium in extragalactic objects. within the central few hundred parsec of galaxies, we find enormous amounts of molecular material fueling a wide variety of highly energetic events observed in starbursts ( galaxies undergoing an intense burst of star formation ) and active galactic nuclei ( agn, where activity is driven by the accretion of material onto the nuclear black hole ). here it is presented a brief summary of both the history and the latest results in observational chemistry in distant galaxies. it will be shown how the molecular emission, is a powerful tool to explore the physics of the dust - enshrouded, buried nuclei of distant ultraluminous galaxies, which are heavily obscured at other wavelengths. special attention will be given to the possibilities offered by next generationinstruments such as alma ( atacama large millimeter array ), expected to have a vast impact on the field of extragalactic chemistry. molecular studies in the early universe will become available at unprecedented sensitivity and resolution. | arxiv:0908.3016 |
the electrical resistivity rho of the iron - arsenide superconductor ba1 - xkxfe2as2 was measured in applied pressures up to 2. 6 gpa for four underdoped samples, with x = 0. 16, 0. 18, 0. 19 and 0. 21. the antiferromagnetic ordering temperature t _ n, detected as a sharp anomaly in rho ( t ), decreases linearly with pressure. at pressures above around 1. 0 gpa, a second sharp anomaly is detected at a lower temperature t _ 0, which rises with pressure. we attribute this second anomaly to the onset of a phase that causes a reconstruction of the fermi surface. this new phase expands with increasing x and it competes with superconductivity. we discuss the possibility that a second spin - density wave orders at t _ 0, with a q vector distinct from that of the spin - density wave that sets in at t _ n. | arxiv:1205.6730 |
we derive the allowed ranges of the spin - - independent interaction cross section $ \ sigsip $ for the elastic scattering of neutralinos on proton for wide ranges of parameters of the general minimal supersymmetric standard model. we investigate the effects of the lower limits on higgs and superpartner masses from colliders, as well as the impact of constraints from $ \ bsgamma $ and the new measurement of $ \ gmtwo $ on the upper and lower limits on $ \ sigsip $. we further explore the impact of the neutralino relic density, including coannihilation, and of theoretical assumptions about the largest allowed values of the supersymmetric parameters. for $ \ mu > 0 $, requiring the latter to lie below $ 1 \ tev $ leads to $ \ sigsip \ gsim 10 ^ { - 11 } \ pb $ at $ \ mchi \ sim100 \ gev $ and $ \ sigsip \ gsim 10 ^ { - 8 } \ pb $ at $ \ mchi \ sim1 \ tev $. when the supersymmetric parameters are allowed above $ 1 \ tev $, for $ 440 \ gev \ lsim \ mchi \ lsim 1020 \ gev $ we derive a { \ em parameter - - independent lower limit } of $ \ sigsip \ gsim 2 \ times 10 ^ { - 12 } \ pb $. ( no similar lower limits can be set for $ \ mu < 0 $ nor for $ 1020 \ gev \ lsim \ mchi \ lsim2. 6 \ tev $. ) requiring $ \ abundchi < 0. 3 $ implies a { \ em parameter - - independent upper limit } $ \ mchi \ lsim2. 6 \ tev $. the new $ \ epem $ - - based measurement of $ ( g - 2 ) _ { \ mu } $ restricts $ \ mchi \ lsim 350 \ gev $ at $ 1 \ sigma $ cl and $ \ mchi \ lsim515 \ gev $ at $ 2 \ sigma $ cl, and implies $ \ mu > 0 $. the largest allowed values of $ \ sigsip $ have already become accessible to recent experimental searches. | arxiv:hep-ph/0208069 |
this is a survey for the 2015 ams summer institute on algebraic geometry about the frobenius type techniques recently used extensively in positive characteristic algebraic geometry. we first explain the basic ideas through simple versions of the fundamental definitions and statements, and then we survey most of the recent algebraic geometry results obtained using these techniques. | arxiv:1610.03390 |
we report the x - ray study for the pyrochlore oxide cd2re2o7. two symmetry - lowering structural transitions were observed at ts1 = 200k and ts2 = 120k. the former is of the second order from the ideal cubic pyrochlore structure with space group fd - 3m to a tetragonally distorted structure with i - 4m2, while the latter is of the first order likely to another tetragonal space group i4122. we discuss the feature of the lattice deformation. | arxiv:cond-mat/0207497 |
we present the snapshot hubble u - band cluster survey ( shucs ), a project aimed at characterizing the star cluster populations of ten nearby galaxies ( d < 23 mpc, half within 12 mpc ) through new f336w ( u band equivalent ) imaging from wfc3, and archival bvi - equivalent data with hst. completing the ubvi baseline reduces the age - extinction degeneracy of optical colours, thus enabling the measurement of reliable ages and masses for the thousands of clusters covered by our survey. the sample consists chiefly of face - on spiral galaxies at low inclination, in various degrees of isolation ( isolated, in group, merging ), and includes two agn hosts. this first paper outlines the survey itself, the observational datasets, the analysis methods, and presents a proof - of - concept study of the large - scale properties and star cluster population of ngc 4041, a massive sabc galaxy at a distance of 23 mpc, and part of a small grouping of six giant members. we resolve two structural components with distinct stellar populations, a morphology more akin to merging and interacting systems. we also find strong evidence of a truncated, schechter - type mass function, and a similarly segmented luminosity function. these results indicate that binning must erase much of the substructure present in the mass and luminosity functions, and might account for the conflicting reports on the intrinsic shape of these functions in the literature. we also note a tidal feature in the outskirts of the galaxy in galex uv imaging, and follow it up with a comprehensive multi - wavelength study of ngc 4041 and its parent group. we deduce a minor merger as a likely cause of its segmented structure and the observed pattern of a radially decreasing star formation rate. we propose that combining the study of star cluster populations with broad - band metrics is not only advantageous, but often easily achievable through archival datasets. | arxiv:1302.6598 |
it is well - known that solutions to the basic problem in the calculus of variations may fail to be lipschitz continuous when the lagrangian depends on t. similarly, for viscosity solutions to time - dependent hamilton - jacobi equations one cannot expect lipschitz bounds to hold uniformly with respect to the regularity of coefficients. this phenomenon raises the question whether such solutions satisfy uniform estimates in some weaker norm. we will show that this is the case for a suitable h \ " older norm, obtaining uniform estimates in ( x, t ) for solutions to first and second order hamilton - jacobi equations. our results apply to degenerate parabolic equations and require superlinear growth at infinity, in the gradient variables, of the hamiltonian. proofs are based on comparison arguments and representation formulas for viscosity solutions, as well as weak reverse h \ " older inequalities. | arxiv:0903.5197 |
in this contribution we discuss about numerical modeling of nebulae. in particular we emphasize on the dynamical evolution of an hii region and the chemical structure of a photodissociation region. we do this using the smoothed particles hydrodynamics code seren and the recently developed astrochemistry code 3d - pdr, respectively. we show an example application by simulating a cometary globule using these two codes. | arxiv:1208.3116 |
a two higgs doublet model is employed to study the production of a cp - odd higgs boson ( $ a $ ) associated with a large transverse momentum jet ( $ j $ ) at hadron supercolliders. the cross section of $ pp \ to ja + x $ is evaluated with four subprocesses : $ gg \ to ga $, $ gq \ to qa $, $ g \ bar { q } \ to \ bar { q } a $ and $ q \ bar { q } \ to ga $. we find that $ pp \ to ja + x $ is a significant source of cp - odd higgs bosons at future hadron supercolliders. | arxiv:hep-ph/9310206 |
we consider two types of random networks grown in blocks. hooking networks are grown from a set of graphs as blocks, each with a labelled vertex called a hook. at each step in the growth of the network, a vertex called a latch is chosen from the hooking network and a copy of one of the blocks is attached by fusing its hook with the latch. bipolar networks are grown from a set of directed graphs as blocks, each with a single source and a single sink. at each step in the growth of the network, an arc is chosen and is replaced with a copy of one of the blocks. using p \ ' olya urns, we prove normal limit laws for the degree distributions of both networks. we extend previous results by allowing for more than one block in the growth of the networks and by studying arbitrarily large degrees. | arxiv:1910.13881 |
image inpainting is a widely used technique in computer vision for reconstructing missing or damaged pixels in images. recent advancements with generative adversarial networks ( gans ) have demonstrated superior performance over traditional methods due to their deep learning capabilities and adaptability across diverse image domains. residual networks ( resnet ) have also gained prominence for their ability to enhance feature representation and compatibility with other architectures. this paper introduces a novel architecture combining gan and resnet models to improve image inpainting outcomes. our framework integrates three components : transpose convolution - based gan for guided and blind inpainting, fast resnet - convolutional neural network ( fr - cnn ) for object removal, and co - modulation gan ( co - mod gan ) for refinement. the model ' s performance was evaluated on benchmark datasets, achieving accuracies of 96. 59 % on image - net, 96. 70 % on places2, and 96. 16 % on celeba. comparative analyses demonstrate that the proposed architecture outperforms existing methods, highlighting its effectiveness in both qualitative and quantitative evaluations. | arxiv:2412.19000 |
the study presents a novel approach for quantifying cellular interactions in digital pathology using deep learning - based image cytometry. traditional methods struggle with the diversity and heterogeneity of cells within tissues. to address this, we introduce the spatial interaction potential ( sip ) and the co - localization index ( cli ), leveraging deep learning classification probabilities. sip assesses the potential for cell - to - cell interactions, similar to an electric field, while cli incorporates distances between cells, accounting for dynamic cell movements. our approach enhances traditional methods, providing a more sophisticated analysis of cellular interactions. we validate sip and cli through simulations and apply them to colorectal cancer specimens, demonstrating strong correlations with actual biological data. this innovative method offers significant improvements in understanding cellular interactions and has potential applications in various fields of digital pathology. | arxiv:2408.16008 |
muon colliders offer special opportunities to discover and study new physics. with the high intensity source of muons at the front end, orders of magnitude improvements would be realized in searches for rare muon processes, in deep inelastic muon and neutrino scattering experiments, and in long - baseline neutrino oscillation experiments. at a 100 to 500 gev muon collider, neutral higgs boson ( or techni - particle ) masses, widths and couplings could be precisely measured via s - channel production. also, threshold cross - section studies of w + w -, t t - bar, zh and supersymmetric particle pairs would precisely determine the corrresponding masses and test supersymmetric radiative corrections. at the high energy frontier a 3 to 4 tev muon collider is ideally suited for the study of scalar supersymmetric particles and extra z - bosons or strong ww scattering. | arxiv:hep-ph/9803480 |
in this paper, we present astrophysical parameters of the open cluster king 13 based on the vi ccd and 2mass jhks photometric data. this is a poorly studied cluster, for which new results have been found in the present work. to identify probable members, we use proper motion data from gaia dr2 catalogue. the mean proper motion of the cluster is determined as - 2. 8 \ pm 0. 2 and - 0. 88 \ pm 0. 14 mas yr { - 1 } and cluster extent is derived as 3 '. 2. using color - magnitude diagrams, we estimate the age and distance of the cluster as 510 \ pm 60 myr and 3. 84 \ pm 0. 15 kpc respectively. interstellar reddening e ( b - v ) in the direction of the cluster is determined as 0. 80 \ pm 0. 2 mag using color - color diagram. mass function slope of the cluster is found to be comparable with the salpeter value. the total mass of this cluster is derived as 270 m _ { \ odot }. the present analysis shows that king 13 is a dynamically relaxed cluster. | arxiv:2001.07398 |
population - transfer schemes are commonly used to convert information robustly stored in some quantum system for manipulation and memory into more macroscopic degrees of freedom for measurement. these schemes may include, e. g., spin - to - charge conversion for spins in quantum dots, detuning of charge qubits between a noise - insensitive operating point and a measurement point, spatial shuttling of qubits encoded in spins or ions, and parity - to - charge conversion schemes for qubits based on majorana zero modes. a common strategy is to use a slow ( adiabatic ) conversion. however, in an adiabatic scheme, the adiabaticity conditions, on the one hand, and accumulation of errors through dephasing, leakage, and energy relaxation processes on the other hand, limit the fidelity that can be achieved. here, we give explicit fast quasiadiabatic ( fast - quad ) conversion strategies ( pulse shapes ) beyond the adiabatic approximation that allow for optimal state conversion. in contrast with many other approaches, here we account for noise in combination with pulse shaping. although we restrict to noise sources that can be modeled by a classical fluctuating parameter, we allow generally for anisotropic nongaussian noise that is nevertheless sufficiently weak to lead to a small error. inspired by analytic methods that have been developed for dynamical decoupling theory, we provide a general framework for unique noise mitigation strategies that can be tailored to the system and environment of interest. | arxiv:2203.07517 |
most of compact binary systems are expected to circularize before the frequency of emitted gravitational waves ( gws ) enters the sensitivity band of the ground based interferometric detectors. however, several mechanisms have been proposed for the formation of binary systems, which retain eccentricity throughout their lifetimes. since no matched - filtering algorithm has been developed to extract continuous gw signals from compact binaries on orbits with low to moderate values of eccentricity, and available algorithms to detect binaries on quasi - circular orbits are sub - optimal to recover these events, in this paper we propose a search method for detection of gravitational waves produced from the coalescences of eccentric binary black holes ( ebbh ). we study the search sensitivity and the false alarm rates on a segment of data from the second joint science run of ligo and virgo detectors, and discuss the implications of the eccentric binary search for the advanced gw detectors. | arxiv:1511.09240 |
recent works have shown the superior robustness of four - dimensional ( 4d ) radar - based three - dimensional ( 3d ) object detection in adverse weather conditions. however, processing 4d radar data remains a challenge due to the large data size, which require substantial amount of memory for computing and storage. in previous work, an online density reduction is performed on the 4d radar tensor ( 4drt ) to reduce the data size, in which the density reduction level is chosen arbitrarily. however, the impact of density reduction on the detection performance and memory consumption remains largely unknown. in this paper, we aim to address this issue by conducting extensive hyperparamter tuning on the density reduction level. experimental results show that increasing the density level from 0. 01 % to 50 % of the original 4drt density level proportionally improves the detection performance, at a cost of memory consumption. however, when the density level is increased beyond 5 %, only the memory consumption increases, while the detection performance oscillates below the peak point. in addition to the optimized density hyperparameter, we also introduce 4d sparse radar tensor ( 4dsrt ), a new representation for 4d radar data with offline density reduction, leading to a significantly reduced raw data size. an optimized development kit for training the neural networks is also provided, which along with the utilization of 4dsrt, improves training speed by a factor of 17. 1 compared to the state - of - the - art 4drt - based neural networks. all codes are available at : https : / / github. com / kaist - avelab / k - radar. | arxiv:2303.06342 |
the majority of model reduction approaches use an efficient representation of the state and then derive equations to temporally evolve the coefficients that encode the state in the representation. in this paper, we instead employ an efficient representation of the entire trajectory of the state over some time interval and solve for the coefficients that define the trajectory on the interval. we use spectral proper orthogonal decomposition ( spod ) modes, in particular, which possess properties that make them suitable for model reduction and are known to provide an accurate representation of trajectories. in fact, with the same number of total coefficients, the spod representation is substantially more accurate than any representation formed by specifying the coefficients in a spatial ( e. g., pod ) basis for the many time steps that make up the interval. we develop a method to solve for the spod coefficients that encode the trajectories in forced linear dynamical systems given the forcing and initial condition, thereby obtaining the accurate representation of the trajectory. we apply the method to two examples, a linearized ginzburg - landau problem and an advection - diffusion problem. in both, the error of the proposed method is orders of magnitude lower than both pod - galerkin and balanced truncation applied to the same problem, as well as the most accurate solution within the span of the pod modes. the method is also fast, with cpu time comparable to or lower than both benchmarks in the examples we present. | arxiv:2407.03334 |
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