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April 2020 arXiv papers — page 40

Showing 3,9014,000 of 15,077 papers

  1. Emil Jeřábek

    We investigate the proof complexity of extended Frege (EF) systems for basic transitive modal logics (K4, S4, GL, ...) augmented with the bounded branching axioms $\mathbf{BB}_k$. First, we study feasibility of the disjunction property and more general extension rules in EF systems for these logics: we show that the corresponding decision problems reduce to

  2. Shengwei Zeng, Chi Sin Tang, Xinmao Yin, Changjian Li

    Infinite-layer Nd1-xSrxNiO2 thin films with Sr doping level x from 0.08 to 0.3 were synthesized and investigated. We found a superconducting dome to be between 0.12 and 0.235 which is accompanied by a weakly insulating behaviour in both underdoped and overdoped regimes. The dome is akin to that in the electron-doped 214-type and infinite-layer cuprate superc

  3. Matthew Otten, Imène R. Goumiri, Benjamin W. Priest, George F. Chapline

    Quantum computers have the opportunity to be transformative for a variety of computational tasks. Recently, there have been proposals to use the unsimulatably of large quantum devices to perform regression, classification, and other machine learning tasks with quantum advantage by using kernel methods. While unsimulatably is a necessary condition for quantum

  4. Pietro Bonato, Paolo Cintia, Francesco Fabbri, Daniele Fadda

    Understanding collective mobility patterns is crucial to plan the restart of production and economic activities, which are currently put in stand-by to fight the diffusion of the epidemics. In this report, we use mobile phone data to infer the movements of people between Italian provinces and municipalities, and we analyze the incoming, outcoming and interna

  5. Samet Gul, Erkan Zergeroglu, Enver Tatlicioglu, Mesih Veysi Kilinc

    This work presents the design and the corresponding stability analysis of desired model based, joint position constrained, robot controller. Specifically, provided that the initial joint position tracking error signal starts below some predefined value, the proposed controller ensures that the joint tracking error signal remains inside the region (defined by

  6. Ji-Ping Dai, Jun-Qing Xia

    In this paper, we study the evolution of the ionization fraction $x_e(z)$ during the epoch of reionization by using the dispersion measurements (DMs) of fast radio bursts (FRBs). Different from the previous studies, here we turn to consider the large-scale clustering information of observed DMs of FRB catalog, which only needs the rough redshift distribution

  7. Enrico Massa, Carlo Paolo Sasso, Matteo Fretto, Luca Martino

    The measurement of the Si lattice parameter by x-ray interferometry assumes the use of strain-free crystals, which might not be true because of intrinsic stresses due to surface relaxation, reconstruction, and oxidation. We used x-ray phase-contrast topography to investigate the strain sensitivity to the finishing, annealing, and coating of the interferomete

  8. Wolfgang Gregor Hollik, Matthias Linster, Mustafa Tabet

    Searches for New Physics focus either on the direct production of new particles at colliders or at deviations from known observables at low energies. In order to discover New Physics in precision measurements, both experimental and theoretical uncertainties must be under full control. Laser spectroscopy nowadays offers a tool to measure transition frequencie

  9. Jianhe Yuan, Zhihai He

    Effective defense of deep neural networks against adversarial attacks remains a challenging problem, especially under powerful white-box attacks. In this paper, we develop a new method called ensemble generative cleaning with feedback loops (EGC-FL) for effective defense of deep neural networks. The proposed EGC-FL method is based on two central ideas. First

  10. Lucia Fornasari, Marco Passoni, Franco Marabelli, Yuyao Chen

    The polarization- and angle- resolved optical response of the anapole mode in silicon nano-disks array have been experimentally and theoretically investigated. The good agreement betweenmeasured data and simulations yields to a consistent description of the anapole mode behaviorthat exhibits different features for TE or TM polarization excitation. Scattering

  11. Martin Jesenko, Bernd Schmidt

    We derive geometrically linearized theories for incompressible materials from nonlinear elasticity theory in the small displacement regime. Our nonlinear stored energy densities may vary on the same (small) length scale as the typical displacements. This allows for applications to multiwell energies as, e.g., encountered in martensitic phases of shape memory

  12. Zehan Li, Sayan Choudhury, W. Vincent Liu

    Motivated by the question of whether all fast scramblers are holographically dual to quantum gravity, we study the dynamics of a non-integrable spin chain model composed of two ingredients - a nearest neighbor Ising coupling, and an infinite range $XX$ interaction. Unlike other fast scrambling many-body systems, this model is not known to be dual to a black

  13. Ayan Chatterjee, Amit Ghosh, Suresh Jaryal

    This paper deals with a detail study of gravitational collapse of dust and viscous fluids under the assumptions of spherical symmetry. Our main goal is to closely analyze the horizons which arise during this gravitational phenomenon. To this end, we examine the formation and evolution of trapped surfaces in these spacetimes, with special attention to trapped

  14. H. L. Che, Z. Y. Zhao, X. Rao, L. G. Chu

    Rare-earth pyrochlores are known to exhibit exotic magnetic phenomena. We report a study of crystal growth and characterizations of a new rare-earth compound Er$_2$AlSbO$_7$, in which Al$^{3+}$ and Sb$^{5+}$ ions share the same positions with a random distribution. The magnetism are studied by magnetic susceptibility, specific heat and thermal conductivity m

  15. Carlo Marcati, Christoph Schwab

    In a plane polygon $P$ with straight sides, we prove analytic regularity of the Leray-Hopf solution of the stationary, viscous, and incompressible Navier-Stokes equations. We assume small data, analytic volume force and no-slip boundary conditions. Analytic regularity is quantified in so-called countably normed, corner-weighted spaces with homogeneous norms.

  16. Marina Orio, Jeremy J. Drake, Jan-Uwe Ness, E. Behar

    The recurrent nova (RN) V3890 Sgr was observed during the 7th day after the onset of its most recent outburst, with the Chandra ACIS-S camera and High Energy Transmission Gratings (HETG). A rich emission line spectrum was detected, due to transitions of Fe-L and K-shell ions ranging from neon to iron. The measured absorbed flux is $\approx 10^{-10}$ erg cm$^

  17. Lukas Hedegaard, Omar Ali Sheikh-Omar, Alexandros Iosifidis

    Domain Adaptation is the process of alleviating distribution gaps between data from different domains. In this paper, we show that Domain Adaptation methods using pair-wise relationships between source and target domain data can be formulated as a Graph Embedding in which the domain labels are incorporated into the structure of the intrinsic and penalty grap

  18. Lachlan P. Lindoy, Thomas P. Fay, David E. Manolopoulos

    Radical pair recombination reactions are known to be sensitive to extremely weak magnetic fields, and can therefore be said to function as molecular magnetoreceptors. The classic example is a carotenoid-porphyrin-fullerene (C+PF-) radical pair that has been shown to provide a "proof-of-principle" for the operation of a chemical compass [K. Maeda et al., Natu

  19. F. Hadi Madjid, John M. Myers

    Entangled states of light exhibit measurable correlations between light detections at separated locations. These correlations are exploited in entangled-state quantum key distribution. To do so involves setting up and maintaining a rhythm of communication among clocks at separated locations. Here, we try to disentangle our thinking about clocks as used in ac

  20. Luciano Abadias, Gissell Estrada-Rodriguez, Ernesto Estrada

    We propose a model for the transmission of perturbations across the amino acids of a protein represented as an interaction network. The dynamics consists of a Susceptible-Infected (SI) model based on the Caputo fractional-order derivative. We find an upper bound to the analytical solution of this model which represents the worse-case scenario on the propagat

  21. Sascha Agne, Jeongwan Jin, Katanya B. Kuntz, Filippo M. Miatto

    The Hong-Ou-Mandel (HOM) effect ranks among the most notable quantum interference phenomena, and is central to many applications in quantum technologies. The fundamental effect appears when two independent and indistinguishable photons are superimposed on a beam splitter, which achieves a complete suppression of coincidences between the two output ports. Muc

  22. Tomás Liendro, Sebastián Zudaire

    Robotic research over the last decades have lead us to different architectures to automatically synthesise discrete event controllers and implement these motion and task plans in real-world robot scenarios. However, these architectures usually build on existing robot hardware, generating as a result solutions that are influenced and/or restricted in their de

  23. Dustin McPhate

    We extend recent results in order to construct projective resolutions for modules over twisted tensor products of truncated polynomial rings. We begin by taking note of the conditions necessary to think of these algebras as a type of Ore extension. We then use this parallel with Ore extensions to develop a method for constructing projective resolutions. Fina

  24. Andres Luna, Silvia Nagy, Chris White

    The double copy relates scattering amplitudes in gauge and gravity theories. It has also been extended to classical solutions, and a number of approaches have been developed for doing so. One of these involves expressing fields in a variety of (super-)gravity theories in terms of convolutions of gauge fields, including also BRST ghost degrees of freedom that

  25. Masoud Sabzevari

    Applying the equivariant moving frames method, we construct convergent normal forms for real-analytic 5-dimensional totally nondegenerate CR submanifolds of C^4. These CR manifolds are divided into several biholomorphically inequivalent subclasses, each of which has its own complete normal form. Moreover it is shown that, biholomorphically, Beloshapka's cubi

  26. H. A. Mohtashami-Borzadaran, M. Amini, H. Jabbari, A. Dolati

    In this paper, we present a new Marshall-Olkin exponential shock model. The new construction method gives the proposed model further ability to allocate the common joint shock on each of the components, making it suitable for application in fields like reliability and credit risk. The given model has a singular part and supports both positive and negative de

  27. Jingwei Hu, Kunlun Qi

    We introduce a fast Fourier spectral method for the spatially homogeneous Boltzmann equation with non-cutoff collision kernels. Such kernels contain non-integrable singularity in the deviation angle which arise in a wide range of interaction potentials (e.g., the inverse power law potentials). Albeit more physical, the non-cutoff kernels bring a lot of diffi

  28. A. Rene Geist, Sebastian Trimpe

    The identification of the constrained dynamics of mechanical systems is often challenging. Learning methods promise to ease an analytical analysis, but require considerable amounts of data for training. We propose to combine insights from analytical mechanics with Gaussian process regression to improve the model's data efficiency and constraint integrity. Th

  29. Khaoula El Mekkaoui, Diego Mesquita, Paul Blomstedt, Samuel Kaski

    Stochastic gradient MCMC methods, such as stochastic gradient Langevin dynamics (SGLD), employ fast but noisy gradient estimates to enable large-scale posterior sampling. Although we can easily extend SGLD to distributed settings, it suffers from two issues when applied to federated non-IID data. First, the variance of these estimates increases significantly

  30. Floris van der Tak, François Lique, Alex Faure, John Black

    The Leiden Atomic and Molecular Database (LAMDA) collects spectroscopic information and collisional rate coefficients for molecules, atoms, and ions of astrophysical and astrochemical interest. We describe the developments of the database since its inception in 2005, and outline our plans for the near future. Such a database is constrained both by the nature

  31. Parisa Fard Moshiri, Hojjat Navidan, Reza Shahbazian, Seyed Ali Ghorashi

    Indoor human activity recognition (HAR) explores the correlation between human body movements and the reflected WiFi signals to classify different activities. By analyzing WiFi signal patterns, especially the dynamics of channel state information (CSI), different activities can be distinguished. Gathering CSI data is expensive both from the timing and equipm

  32. Hongpeng Sun, Xuecheng Tai, Jing Yuan

    The Potts model has many applications. It is equivalent to some min-cut and max-flow models. Primal-dual algorithms have been used to solve these problems. Due to the special structure of the models, convergence proof is still a difficult problem. In this work, we developed two novel, preconditioned, and over-relaxed alternating direction methods of multipli

  33. Mylene Pischella, Arsenia Chorti, Inbar Fijalkow

    A new multiple access (MA) strategy, referred to as non orthogonal multiple access - Relevant (NOMA-R), allows selecting NOMA when this increases all individual rates, i.e., it is beneficial for both strong(er) and weak(er) individual users. This letter provides a performance analysis of the NOMA-R strategy in uplink networks with statistical delay constrain

  34. Jennifer G. Winters, Jonathan M. Irwin, David Charbonneau, David W. Latham

    We present the spectroscopic orbits of eleven nearby, mid-to-late M dwarf binary systems in a variety of configurations: two single-lined binaries (SB1s), seven double-lined binaries (SB2s), one double-lined triple (ST2), and one triple-lined triple (ST3). Eight of these orbits are the first published for these systems, while five are newly identified multip

  35. Valenti Bosch-Ramon, Nicola Bellomo

    Dark matter may consist, at least partially, of primordial black holes formed during the radiation-dominated era. The radiation produced by accretion onto primordial black holes leaves characteristic signatures on the properties of the medium at high redshift, before and after Hydrogen recombination. Therefore, reliable modelling of accretion onto these obje

  36. Shuang Du, Weihua Wang, Xuhao Wu, Renxin Xu

    We propose a geometrical explanation for periodically and nonperiodically repeating fast radio bursts (FRBs) under neutron star (NS)-companion systems. We suggest a constant critical binary separation, $r_{\rm c}$, within which the interaction between the NS and companion can trigger FRB bursts. For an elliptic orbit with the minimum and maximum binary separ

  37. Julia Kreutzer, Nathaniel Berger, Stefan Riezler

    Sequence-to-sequence learning involves a trade-off between signal strength and annotation cost of training data. For example, machine translation data range from costly expert-generated translations that enable supervised learning, to weak quality-judgment feedback that facilitate reinforcement learning. We present the first user study on annotation cost and

  38. A. Schmidt, J. R. Pybus, R. Weiss, E. P. Segarra

    The strong nuclear interaction between nucleons (protons and neutrons) is the effective force that holds the atomic nucleus together. This force stems from fundamental interactions between quarks and gluons (the constituents of nucleons) that are described by the equations of Quantum Chromodynamics (QCD). However, as these equations cannot be solved directly

  39. Mohd. Danish Siddiqi, Mehmet Akif Akyol

    In this research article, we establish the geometrical bearing on Riemannian submersions in terms of $\eta$-Ricci-Yamabe Soliton with the potential field and giving the classification of any fiber of Riemannian submersion is an $\eta$-Ricci-Yamabe soliton, $\eta$-Ricci soliton and $\eta$-Yamabe soliton. We also discuss the various conditions for which the ta

  40. Franco Dassi, Joscha Gedicke, Lorenzo Mascotto

    We present an hp-adaptive virtual element method (VEM) based on the hypercircle method of Prager and Synge for the approximation of solutions to diffusion problems. We introduce a reliable and efficient a posteriori error estimator, which is computed by solving an auxiliary global mixed problem. We show that the mixed VEM satisfies a discrete inf-sup conditi

  41. Irina Vortkamp, Sebastian J. Schreiber, Alan Hastings, Frank M. Hilker

    We present a discrete-time model of a spatially structured population and explore the effects of coupling when the local dynamics contain a strong Allee effect and overcompensation. While an isolated population can exhibit only bistability and essential extinction, a spatially structured population can exhibit numerous coexisting attractors. We identify mech

  42. Peng Zhao, Xinsheng Tan, Haifeng Yu, Shi-Liang Zhu

    We propose an approach to simultaneously excite two atoms by using cavity-assisted Raman process in combination with cavity photon-mediated interaction. The system consists of a two-level atom and a $\Lambda$-type or V-type three-level atom, which are coupled together with a cavity mode. Having derived the effective Hamiltonian, we find that under certain ci

  43. Ghislain Fourny

    This paper contributes a new class of games called spacetime games with perfect information. In spacetime games, the agents make decisions at various positions in Minkowski spacetime. Spacetime games can be seen as the least common denominator of strategic games on the one hand, and dynamic games with perfect information on the other hand. Indeed, strategic

  44. Galina Shchelkanova, Kohei Hayashi, Sergei Blinnikov

    We present nearly self-consistent stellar-halo models of the Fornax dwarf spheroidal galaxy associated with the Milky Way galaxy. Such galaxies are dominated by dark matter and have almost no gas in the system. Therefore, they are excellent objects for N-body modeling that takes into account visible and dark matter halo components. In order to model the dark

  45. P. Senger, for the CBM collaboration

    The future Facility for Antiproton and Ion Research (FAIR) is an accelerator-based international center for fundamental and applied research, which presently is under construction in Darmstadt, Germany. An important part of the program is devoted to questions related to astrophysics, including the origin of elements in the universe and the properties of stro

  46. Christian Bertram, Heike Faßbender

    The approximate solution of large-scale algebraic Riccati equations is considered. We are interested in approximate solutions which yield a Riccati residual matrix of a particular small rank. It is assumed that such approximate solutions can be written in factored form $ZYZ^*$ with a rectangular matrix $Z$ and a small quadratic matrix $Y$. We propose to choo

  47. Qianqian Zhou, Alexander Sakhanenko, Junyi Guo

    Prokhorov distances under sublinear expectations are presented in CLT and functional CLT, and the convergence rates for them are obtained by Lindeberg method. In particular, the obtained estimate in functional CLT yields known Borovkov's estimate in classical functional CLT with explicit constant.

  48. Nicholas Chimitt, Stanley H. Chan

    Simulating atmospheric turbulence is an essential task for evaluating turbulence mitigation algorithms and training learning-based methods. Advanced numerical simulators for atmospheric turbulence are available, but they require evaluating wave propagation which is computationally expensive. In this paper, we present a propagation-free method for simulating

  49. R. L. C. Starling, . A. Rowlinson, A. J. van der Horst, R. A. M. J. Wijers

    The prompt emission in long gamma-ray bursts arises from within relativistic outflows created during the collapse of massive stars, and the mechanism by which radiation is produced may be either magnetically- or matter-dominated. In this work we suggest an observational test of a magnetically-dominated Poynting flux model that predicts both gamma-ray and low

  50. Yaru Hao, Li Dong, Furu Wei, Ke Xu

    The great success of Transformer-based models benefits from the powerful multi-head self-attention mechanism, which learns token dependencies and encodes contextual information from the input. Prior work strives to attribute model decisions to individual input features with different saliency measures, but they fail to explain how these input features intera

  51. Pranav Gokhale, Ali Javadi-Abhari, Nathan Earnest, Yunong Shi

    Quantum computers are traditionally operated by programmers at the granularity of a gate-based instruction set. However, the actual device-level control of a quantum computer is performed via analog pulses. We introduce a compiler that exploits direct control at this microarchitectural level to achieve significant improvements for quantum programs. Unlike qu

  52. Nicola Demo, Giulio Ortali, Gianluca Gustin, Gianluigi Rozza

    This contribution describes the implementation of a data--driven shape optimization pipeline in a naval architecture application. We adopt reduced order models (ROMs) in order to improve the efficiency of the overall optimization, keeping a modular and equation-free nature to target the industrial demand. We applied the above mentioned pipeline to a realisti

  53. Kari Ruotsalainen, Matteo Gatti, James M. Ablett, Flora Yakhou-Harris

    We present a temperature and doping dependent resonant inelastic X-ray scattering experiment at the V L$_{2,3}$ and O K edges in La$_{1-x}$Sr$_x$VO$_3$ for $x=0$ and $x=0.1$. This material is a canonical example of a compound that exhibits a filling control metal-insulator transition and undergoes orbital ordering and antiferromagnetic transitions at low tem

  54. Antoine Grospellier, Lucien Grouès, Anirudh Krishna, Anthony Leverrier

    Hypergraph product codes are a class of constant-rate quantum low-density parity-check (LDPC) codes equipped with a linear-time decoder called small-set-flip (SSF). This decoder displays sub-optimal performance in practice and requires very large error correcting codes to be effective. In this work, we present new hybrid decoders that combine the belief prop

  55. Fabrizio Frasca, Emanuele Rossi, Davide Eynard, Ben Chamberlain

    Graph representation learning has recently been applied to a broad spectrum of problems ranging from computer graphics and chemistry to high energy physics and social media. The popularity of graph neural networks has sparked interest, both in academia and in industry, in developing methods that scale to very large graphs such as Facebook or Twitter social n

  56. Frank Dignum, Virginia Dignum, Paul Davidsson, Amineh Ghorbani

    During the COVID-19 crisis there have been many difficult decisions governments and other decision makers had to make. E.g. do we go for a total lock down or keep schools open? How many people and which people should be tested? Although there are many good models from e.g. epidemiologists on the spread of the virus under certain conditions, these models do n

  57. Goutam Manna, Arijit Panda, Aninda Karmakar, Saibal Ray

    The motto of this work is to generate a general formalism of $f(\bar{R}, L(X))-$gravity in the context of dark energy under the framework of the {\bf K-}essence emergent geometry with the Dirac-Born-Infeld (DBI) variety of action, where $\bar{R}$ is the familiar Ricci scalar, $L(X)$ is the DBI type non-canonical Lagrangian with $X={1\over 2}g^{\mu\nu}\nabla_

  58. Tomohiro Nishiyama, Igal Sason

    The relative entropy and chi-squared divergence are fundamental divergence measures in information theory and statistics. This paper is focused on a study of integral relations between the two divergences, the implications of these relations, their information-theoretic applications, and some generalizations pertaining to the rich class of $f$-divergences. A

  59. Peter A. Streufert

    This paper develops the category $\mathbf{NCG}$. Its objects are node-and-choice games, which include essentially all extensive-form games. Its morphisms allow arbitrary transformations of a game's nodes, choices, and players, as well as monotonic transformations of the utility functions of the game's players. Among the morphisms are subgame inclusions. Seve

  60. Shangzhi Hong, Yuqi Sun, Hanying Li, Henry S. Lynn

    Machine learning iterative imputation methods have been well accepted by researchers for imputing missing data, but they can be time-consuming when handling large datasets. To overcome this drawback, parallel computing strategies have been proposed but their impact on imputation results and subsequent statistical analyses are relatively unknown. This study e

  61. Darij Grinberg

    For any positive integer $k$ and nonnegative integer $m$, we consider the symmetric function $G\left( k,m\right)$ defined as the sum of all monomials of degree $m$ that involve only exponents smaller than $k$. We call $G\left( k,m\right)$ a "Petrie symmetric function" in honor of Flinders Petrie, as the coefficients in its expansion in the Schur basis are de

  62. Mirko Signorelli, Pietro Spitali, Roula Tsonaka

    We present a new modelling approach for longitudinal count data that is motivated by the increasing availability of longitudinal RNA-sequencing experiments. The distribution of RNA-seq counts typically exhibits overdispersion, zero-inflation and heavy tails; moreover, in longitudinal designs repeated measurements from the same subject are typically (positive

  63. Charlotte Wouters, Toni Markurt, Enzo Rotunno, Vincenzo Grillo

    In this work, we emphasize the important contribution of the 2s Bloch wave state to the properties of a STEM electron probe propagating on an atomic column. For a strong enough column potential, the confinement of the 2s state leads to a long-period oscillation of the electron wave function, which is reflected in the resulting STEM-HAADF intensity. We show h

  64. Qianqian Zhou, Alexander Sakhanenko, Junyi Guo

    In this paper, we investigate the ruin probabilities of non-homogeneous risk models. By employing martingale method, the Lundberg-type inequalities of ruin probabilities of non-homogeneous renewal risk models are obtained under weak assumptions. In addition, for the periodic and quasi-periodic risk models the adjustment coefficients of the Lundberg-type ineq

  65. Sergio Davis, Jalaj Jain, Biswajit Bora

    The thermodynamic properties of systems with long-range interactions is still an ongoing challenge, both from the point of view of theory as well as computer simulation. In this work we study a model system, a Coulomb gas confined inside a sphere, by using the Wang-Landau algorithm. We have computed the configurational density of states (CDOS), the thermodyn

  66. Divya Raghavan, Sukavanam Nagarajan

    A non-convex control system governed by a nonlinear impulsive evolution equation of Hilfer fractional order in a Banach space is considered. The existence of admissible state-control pair is established. Then the introduction of suitable measure-valued control convexifies the system, and the relaxed system is obtained. Further, the relaxation theorem for the

  67. Felix Nilsson, Jens Jakobsen, Fernando Alonso-Fernandez

    Industrial manufacturing has developed during the last decades from a labor-intensive manual control of machines to a fully-connected automated process. The next big leap is known as industry 4.0, or smart manufacturing. With industry 4.0 comes increased integration between IT systems and the factory floor from the customer order system to final delivery of

  68. Riku Murai, Sajad Saeedi, Paul H. J. Kelly

    Focal-plane Sensor-processor (FPSP) is a next-generation camera technology which enables every pixel on the sensor chip to perform computation in parallel, on the focal plane where the light intensity is captured. SCAMP-5 is a general-purpose FPSP used in this work and it carries out computations in the analog domain before analog to digital conversion. By e

  69. Christophe Lucas, Matteo Mio

    We design hypersequent calculus proof systems for the theories of Riesz spaces and modal Riesz spaces and prove the key theorems: soundness, completeness and cut elimination. These are then used to obtain completely syntactic proofs of some interesting results concerning the two theories. Most notably, we prove a novel result: the theory of modal Riesz space

  70. Jan Drgona, Aaron Tuor, Draguna Vrabie

    We present differentiable predictive control (DPC), a method for learning constrained neural control policies for linear systems with probabilistic performance guarantees. We employ automatic differentiation to obtain direct policy gradients by backpropagating the model predictive control (MPC) loss function and constraints penalties through a differentiable

  71. Guido Cavallaro, Roberto Garra, Carlo Marchioro

    We discuss the time evolution of a two-dimensional active scalar flow, which extends some properties valid for a two-dimensional incompressible nonviscous fluid. In particular we study some characteristics of the dynamics when the field is initially concentrated in $N$ small disjoint regions, and we discuss the conservation in time of this localization prope

  72. Adar Sharon

    We study "vacuum crossing", which occurs when the vacua of a theory are exchanged as we vary some periodic parameter $\theta$ in a closed loop. We show that vacuum crossing is a useful non-perturbative tool to study strongly-coupled quantum field theories, since finding vacuum crossing in a weakly-coupled regime of the theory can lead to nontrivial consequen

  73. Cosetta Baroni, Giacomo Gori, Maria Luisa Chiofalo, Andrea Trombettoni

    We study the non-linear beam splitter in matter-wave interferometers using ultracold quantum gases in a double-well configuration in presence of non-local interactions inducing inter-well density-density coupling, as they can be realized, e.g., with dipolar gases. We explore this effect after considering different input states, in the form of either coherent

  74. Alexey Galt, Vijay Joshi, Andrey Mamontov, Sergey Shpectorov

    Axial algebras are a class of commutative non-associative algebras generated by idempotents, called axes, with adjoint action semi-simple and satisfying a prescribed fusion law. Axial algebras were introduced by Hall, Rehren and Shpectorov \cite{hrs,hrs1} as a broad generalisation of Majorana algebras of Ivanov, whose axioms were derived from the properties

  75. Naoum Karchev

    We present a unified theory of magnetism and superconductivity of $UGe_2$. To this end, we consider part of $5f$ uranium electrons as mostly itinerant and other ones as mostly localized. The main feature that distinguishes the localized from the itinerant electrons is the effect of the pressure on them. The pressure strongly screens the itinerant electrons w

  76. Artur Jordao, Fernando Akio, Maiko Lie, William Robson Schwartz

    Modern convolutional networks such as ResNet and NASNet have achieved state-of-the-art results in many computer vision applications. These architectures consist of stages, which are sets of layers that operate on representations in the same resolution. It has been demonstrated that increasing the number of layers in each stage improves the prediction ability

  77. Alessandra De Luca, Veronica Felli

    In this work we develop an Almgren type monotonicity formula for a class of elliptic equations in a domain with a crack, in the presence of potentials satisfying either a negligibility condition with respect to the inverse-square weight or some suitable integrability properties. The study of the Almgren frequency function around a point on the edge of the cr

  78. Kristopher Cooper, Iain G. Hannah, Brian W. Grefenstette, Lindsay Glesener

    We present X-ray imaging spectroscopy of one of the weakest active region (AR) microflares ever studied. The microflare occurred at $\sim$11:04 UT on 2018 September 9 and we studied it using the Nuclear Spectroscopic Telescope ARray (NuSTAR) and the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). The microflare is observed clearly in 2.5-

  79. P. Arrabal Haro, J. M. Rodríguez Espinosa, C. Muñoz-Tuñón, D. Sobral

    The differences between the inherent stellar populations (SPs) of LAEs and LBGs are a key factor in understanding early galaxy formation and evolution. We have run a set of SP burst-like models for a sample of 1,558 sources at $3.4<z<6.8$ from the Survey for High-$z$ Absorption Red and Dead Sources (SHARDS) over the GOODS-N field. This work focuses on the di

  80. Patrick Tolksdorf

    The aim of this article is to deepen the understanding of the derivation of $\mathrm{L}^p$-estimates of non-local operators. We review the $\mathrm{L}^p$-extrapolation theorem of Shen which builds on a real variable argument of Caffarelli and Peral and adapt this theorem to account for non-local weak reverse H\"older estimates. These non-local weak reverse H

  81. Victor A. Campos, Guilherme C. M. Gomes, Allen Ibiapina, Raul Lopes

    We investigate a number of coloring problems restricted to bipartite graphs with bounded diameter. First, we investigate the $k$-List Coloring, List $k$-Coloring, and $k$-Precoloring Extension problems on bipartite graphs with diameter at most $d$, proving NP-completeness in most cases, and leaving open only the List $3$-Coloring and $3$-Precoloring Extensio

  82. Olga Y. Kushel, Raffaella Pavani

    We generalize the concepts of D-stability and additive D-stability of matrices. For this, we consider a family of unbounded regions defined in terms of Linear Matrix Inequalities (so-called LMI regions). We study the problem when the localization of a matrix spectrum in an unbounded LMI region is preserved under specific multiplicative and additive perturbat

  83. Luca Fabbri

    We write the most general parity-even re-normalizable Chern-Simons term for massive axial-vector propagating torsion fields. After obtaining the most comprehensive action, we perform the causal structure analysis to see what self-interaction term must be suppressed. In view of such a restriction for the Lagrangian, we will obtain the field equations, investi

  84. Shira Sardi, Roni Vardi, Yuval Meir, Yael Tugendhaft

    Attempting to imitate the brain functionalities, researchers have bridged between neuroscience and artificial intelligence for decades; however, experimental neuroscience has not directly advanced the field of machine learning. Here, using neuronal cultures, we demonstrate that increased training frequency accelerates the neuronal adaptation processes. This

  85. Josep Marti-Saumell, Angel Santamaria-Navarro, Carlos Ocampo-Martinez, Juan Andrade-Cetto

    Today's complex robotic designs comprise in some cases a large number of degrees of freedom, enabling for multi-objective task resolution (e.g., humanoid robots or aerial manipulators). This paper tackles the stability problem of a hierarchical losed-loop inverse kinematics algorithm for such highly redundant robots. We present a method to guarantee system s

  86. Marco Virgolin, Andrea De Lorenzo, Eric Medvet, Francesca Randone

    Many risk-sensitive applications require Machine Learning (ML) models to be interpretable. Attempts to obtain interpretable models typically rely on tuning, by trial-and-error, hyper-parameters of model complexity that are only loosely related to interpretability. We show that it is instead possible to take a meta-learning approach: an ML model of non-trivia

  87. Benjamin Avanzi, Gregory Clive Taylor, Bernard Wong, Xinda Yang

    In this paper, we develop a method to model and estimate several, _dependent_ count processes, using granular data. Specifically, we develop a multivariate Cox process with shot noise intensities to jointly model the arrival process of counts (e.g. insurance claims). The dependency structure is introduced via multivariate shot noise _intensity_ processes whi

  88. Nathalie Tkauc, Thao Tran, Kevin Hernandez-Diaz, Fernando Alonso-Fernandez

    This paper describes the implementation of a system to recognize employees and visitors wanting to gain access to a physical office through face images and speech-to-text recognition. The system helps employees to unlock the entrance door via face recognition without the need of tag-keys or cards. To prevent spoofing attacks and increase security, a randomly

  89. Francesca Bucci, Matthias Eller

    The Cauchy-Dirichlet problem for the Moore-Gibson-Thompson equation is analyzed. With the focus on non-homogeneous boundary data, two approaches are offered: one is based on the theory of hyperbolic equations, while the other one uses the theory of operator semigroups. This is a mixed hyperbolic problem with a characteristic spatial boundary. Hence, the regu

  90. Yuya Masumura, Taihei Oki, Yutaro Yamaguchi

    We study the generalized minimum Manhattan network (GMMN) problem: given a set $P$ of pairs of two points in the Euclidean plane $\mathbb{R}^2$, we are required to find a minimum-length geometric network which consists of axis-aligned segments and contains a shortest path in the $L_1$ metric (a so-called Manhattan path) for each pair in $P$. This problem com

  91. Susanne Dandl, Christoph Molnar, Martin Binder, Bernd Bischl

    Counterfactual explanations are one of the most popular methods to make predictions of black box machine learning models interpretable by providing explanations in the form of `what-if scenarios'. Most current approaches optimize a collapsed, weighted sum of multiple objectives, which are naturally difficult to balance a-priori. We propose the Multi-Objectiv

  92. Daniel A. Jaume, Adrián Pastine, Victor Nicolas Schvöllner

    Given any two forests with the same degree sequence, we show in an algorithmic way that one can be transformed into the other by a sequence of 2-switches in such a way that all the intermediate graphs of the transformation are forests. We also prove that the 2-switch operation perturbs minimally some well-known integer parameters in families of graphs with t

  93. Stefan Ollinger, Lorik Dumani, Premtim Sahitaj, Ralph Bergmann

    Research on computational argumentation is currently being intensively investigated. The goal of this community is to find the best pro and con arguments for a user given topic either to form an opinion for oneself, or to persuade others to adopt a certain standpoint. While existing argument mining methods can find appropriate arguments for a topic, a correc

  94. Kyle P. Kelley, Maxim Ziatdinov, Liam Collins, Michael A. Susner

    Fast scanning probe microscopy enabled via machine learning allows for a broad range of nanoscale, temporally resolved physics to be uncovered. However, such examples for functional imaging are few in number. Here, using piezoresponse force microscopy (PFM) as a model application, we demonstrate a factor of 5.8 improvement in imaging rate using a combination

  95. Ondřej Mokrý, Pavel Rajmic, Pavel Záviška

    The paper presents a unified, flexible framework for the tasks of audio inpainting, declipping, and dequantization. The concept is further extended to cover analogous degradation models in a transformed domain, e.g. quantization of the signal's time-frequency coefficients. The task of reconstructing an audio signal from degraded observations in two different

  96. Matteo Braglia, Mario Ballardini, William T. Emond, Fabio Finelli

    We provide further evidence that a massless cosmological scalar field with a non-minimal coupling to the Ricci curvature of the type $M^2_{\rm pl}(1+\xi \sigma^n/M_{\rm pl}^n) $ alleviates the existing tension between local measurements of the Hubble constant and its inference from CMB anisotropies and baryonic acoustic oscillations data in presence of a cos

  97. Alexander Vidybida

    A method for analyzing sequential data sets, similar to the permutation entropy one, is discussed. The characteristic features of this method are as follows: it preserves information about equal values, if any, in the embedding vectors; it is exempt of combinatorics; it delivers the same entropy value as does the permutation method, provided the embedding ve

  98. Shuang Du

    The origin of gamma-ray burst (GRB) X-ray plateau, especially the internal plateau, is still unclear, but it could be related to GRB's central engine of magnetar. It is generally believed that the spin-down power of the magnetar is injected into forward external shock, however we propose here that most of the power will be dissipated behind the GRB jet throu

  99. Sarah O. M. Saeed, Sanaa Hamid Mohamed, Osama Zwaid Alsulami, Mohammed T. Alresheedi

    In this paper, we use the percentage blockage as a metric when an opaque disc obstructs the Line-of-Sight link from the access point to the receiver in an optical wireless indoor communication system. The effect of the different parameters of the obstructing object are studied, these are the radius, the height, and the horizontal distance from the receiver i

  100. Y. Liu, Y. L. Ye, J. L. Lou, X. F. Yang

    An inelastic excitation and cluster-decay experiment $\rm {^2H}(^{16}C,~{^{4}He}+{^{12}Be}~or~{^{6}He}+{^{10}Be}){^2H}$ was carried out to investigate the linear-chain clustering structure in neutron-rich $\rm {^{16}C}$. For the first time, decay-paths from the $\rm {^{16}C}$ resonances to various states of the final nuclei were determined, thanks to the wel