November 2018 arXiv papers — page 35

Jérôme Rony, Luiz G. Hafemann, Luiz S. Oliveira, Ismail Ben Ayed

Research on adversarial examples in computer vision tasks has shown that small, often imperceptible changes to an image can induce misclassification, which has security implications for a wide range of image processing systems. Considering $L_2$ norm distortions, the Carlini and Wagner attack is presently the most effective white-box attack in the literature

Benjamin Villalonga, Sergio Boixo, Bron Nelson, Christopher Henze

Here we present qFlex, a flexible tensor network based quantum circuit simulator. qFlex can compute both exact amplitudes, essential for the verification of the quantum hardware, as well as low fidelity amplitudes, in order to mimic sampling from Noisy Intermediate-Scale Quantum (NISQ) devices. In this work, we focus on random quantum circuits (RQCs) in the

Harry Johnston, Christos Georgiou, Benjamin Joachimi, Henk Hoekstra

We directly constrain the non-linear alignment (NLA) model of intrinsic galaxy alignments, analysing the most representative and complete flux-limited sample of spectroscopic galaxies available for cosmic shear surveys. We measure the projected galaxy position-intrinsic shear correlations and the projected galaxy clustering signal using high-resolution imagi

Nicolás Quesada

We show that the Franck-Condon Factor (FCF) associated to a transition between initial and final vibrational states in two different potential energy surfaces, having $N$ and $M$ vibrational quanta, respectively, is equivalent to calculating the number of perfect matchings of a weighted graph with loops that has $P = N+M$ vertices. This last quantity is the

A. L. Harris, T. A. Saxton, Z. G. Temple

The Path Integral Quantum Trajectory (PIQTr) model is introduced as a new computational tool for the study of non-relativistic, quantum mechanical wave packets. We introduce the numerical algorithm and show that one of the primary advantages of the PIQTr model is its ability to efficiently handle heavy mass particles, while still resulting in a numerically e

Boris Knyazev, Xiao Lin, Mohamed R. Amer, Graham W. Taylor

Spectral Graph Convolutional Networks (GCNs) are a generalization of convolutional networks to learning on graph-structured data. Applications of spectral GCNs have been successful, but limited to a few problems where the graph is fixed, such as shape correspondence and node classification. In this work, we address this limitation by revisiting a particular

Ben Maybee, Daniel Hodgson, Almut Beige, Robert Purdy

Recently, Bennett et al. [Eur. J. Phys. 37:014001, 2016] presented a physically-motivated and explicitly gauge-independent scheme for the quantisation of the electromagnetic field in flat Minkowski space. In this paper we generalise this field quantisation scheme to curved spacetimes. Working within the standard assumptions of quantum field theory and only p

Massimiliano Grazzini, Stefan Kallweit, Marius Wiesemann, Jeong Yeon Yook

We consider QCD radiative corrections to the production of four charged leptons in hadron collisions. We present the computation of the next-to-leading order QCD corrections to the loop-induced gluon fusion contribution. Our predictions include, for the first time, also the quark-gluon partonic channels. The computed corrections, which are formally of ${\cal

Elias Jarlebring, Max Bennedich, Giampaolo Mele, Emil Ringh

We present NEP-PACK a novel open-source library for the solution of nonlinear eigenvalue problems (NEPs). The package provides a framework to represent NEPs, as well as efficient implementations of many state-of-the-art algorithms. The package makes full use of the efficiency of Julia, yet maintains usability, and integrates well with other software packages

Marco Faggian, Francesco Ginelli, Fernando Rosas, Zoran Levnajić

A sufficiently connected topology linking the constituent units of a complex system is usually seen as a prerequisite for the emergence of collective phenomena such as synchronization. We present a random network of heterogeneous phase oscillators in which the links mediating the interactions are constantly rearranged with a characteristic timescale and, pos

Mats Barkman, Albert Samoilenka, Egor Babaev

Fulde, Ferrell, Larkin, and Ovchinnikov (FFLO) predicted inhomogeneous superconducting and superfluid ground states, spontaneously breaking translation symmetries. In this Letter, we demonstrate that the transition from the FFLO to the normal state as a function of temperature or increased Fermi surface splitting is not a direct one. Instead the system has a

Camilo Posada, Cecilia Chirenti

In this paper we used the theory of adiabatic radial oscillations developed by Chandrasekhar to study the conditions for dynamical stability of constant energy-density stars, or Schwarzschild stars, in the unstudied ultra compact regime beyond the Buchdahl limit, that is, for configurations with radius $R$ in the range $R_{\rm S}<R<(9/8)R_{\rm S}$, where $R_

Liane Gabora, Mike Unrau

The ideas that we forge creatively as individuals and groups build on one another in a manner that is cumulative and adaptive, forming open-ended lineages across space and time. Thus, human culture is believed to evolve. The pervasiveness of cross-domain creativity--as when a song inspires a painting--would appear indicative of discontinuities in cultural li

B. Mishra, Pratik P Ray, S. K. Tripathy, Kazuharu Bamba

We investigate the behaviour of the skewness parameters for an anisotropic universe in the framework of General Relativity. Non interacting dark energy is considered in presence of electromagnetic field. A time varying deceleration parameter simulated by a hybrid scale factor is considered. The dynamics of the universe is investigated in presence and absence

Igor Barahona, Lucía López de Medrano, Barbara Martínez Moreno, Beatríz Limón Gutiérrez

We investigate the impact of mathematics on improving neighbourhood integration and perception of security. The main square of Chamilpa colony in Cuernavaca, M\'exico is take as study case. This city is featured by its precarious recreational and leisurial infrastructure. Chamilpa is among the top of social outcast levels in the city. Data was collected thro

Lilla Juhász, Yoshiharu Omura, János Lichtenberger, Reinhard H. Friedel

In this study we present an inversion method which provides thermal plasma population parameters from characteristics of chorus emissions only. Our ultimate goal is to apply this method to ground based data in order to derive the lower energy boundary condition for many radiation belt models. The first step is to test the chorus-inversion method on in-situ d

Tomislav Begušić, Julien Roulet, Jiří Vaníček

We present a methodology for computing vibrationally and time-resolved pump-probe spectra, which takes into account all vibrational degrees of freedom and is based on the combination of the thawed Gaussian approximation with on-the-fly ab initio evaluation of the electronic structure. The method is applied to the phenyl radical and compared with two more app

Jeremy M. Hutson, C. Ruth Le Sueur

MOLSCAT is a general-purpose program for quantum-mechanical calculations on nonreactive atom-atom, atom-molecule and molecule-molecule collisions. It constructs the coupled-channel equations of atomic and molecular scattering theory, and solves them by propagating the wavefunction or log-derivative matrix outwards from short range to the asymptotic region. I

Milan Milošević, Miika A. Pursiainen, Predrag Jovanović, Luka Č. Popović

The relativistically broadened Fe K$\alpha$ line, originating from the accretion disc in a vicinity of a super massive black hole, is observed in only less than 50\% of type 1 Active Galactic Nuclei (AGN). In this study we investigate could this lack of detections be explained by the effects of certain parameters of the accretion disc and black hole, such as

Vladimir Edemskiy

We investigate the $k$-error linear complexity over $\mathbb{F}_p$ of binary sequences of length $2p$ with optimal three-level autocorrelation. These balanced sequences are constructed by cyclotomic classes of order four using a method presented by Ding et al.

G. Hebrard, A. S. Bonomo, R. F. Diaz, A. Santerne

Whereas thousands of transiting giant exoplanets are known today, only a few are well characterized with long orbital periods. Here we present KOI-3680b, a new planet in this category. First identified by the Kepler team as a promising candidate from the photometry of the Kepler spacecraft, we establish here its planetary nature from the radial velocity foll

Gianmarco Bet

We consider a model for transitory queues in which only a finite number of customers can join. The queue thus operates over a finite time horizon. In this system, also known as the $\Delta_{(i)}/G/1$ queue, the customers decide independently when to join the queue by sampling their arrival time from a common distribution. We prove that, when the queue satisf

Si Zuo, Zhimin Xu

In recent years, the sequence-to-sequence learning neural networks with attention mechanism have achieved great progress. However, there are still challenges, especially for Neural Machine Translation (NMT), such as lower translation quality on long sentences. In this paper, we present a hierarchical deep neural network architecture to improve the quality of

Changsong Xu, Bin Xu, Bertrand Dupé, L. Bellaiche

First-principles calculations, in combination with the four-state energy mapping method, are performed to extract the magnetic interaction parameters of multiferroic BiFeO$_3$. Such parameters include the symmetric exchange (SE) couplings and the Dzyaloshinskii-Moriya (DM) interactions up to second nearest neighbors, as well as the single ion anisotropy (SIA

Leah Epstein

We slightly improve the known lower bound on the asymptotic competitive ratio for online bin packing of rectangles. We present a complete proof for the new lower bound, whose value is above 1.91.

Alexandre Cooper, Won Kyu Calvin Sun, Jean-Christophe Jaskula, Paola Cappellaro

The performance of solid-state quantum sensors based on electronic spin defects is often limited by the presence of environmental spin impurities that cause decoherence. A promising approach to improve these quantum sensors is to convert environment spins into useful resources for sensing. Here we demonstrate the efficient use of an unknown electronic spin d

Xavier Lachaume

In this short note we wonder about the explicit expression of the expanding of the $p$-th Lovelock product. We use the 1990's works of S. A. Fulling et al. on the symmetries of the Riemann tensor, and we show that the number of independent scalars appearing in this expanding is equal to the number of Young diagrams with all row lengths even in the decomposit

Aditya Sundararajan, Tanwir Khan, Amir Moghadasi, Arif I. Sarwat

Synchrophasor devices guarantee situation awareness for real-time monitoring and operational visibility of the smart grid. With their widespread implementation, significant challenges have emerged, especially in communication, data quality and cybersecurity. The existing literature treats these challenges as separate problems, when in reality, they have a co

Karol Dziedziul, Barbara Wolnik

We propose the general way of study the universal estimator for the regression problem in learning theory considered in "Universal algorithms for learning theory Part I: piecewise constant functions" and "Universal algorithms for learning theory Part II: piecewise constant functions" written by Binev, P., Cohen, A., Dahmen, W., DeVore, R., Temlyakov, V. This

Kalliopi Basioti, George V. Moustakides, Emmanouil Z. Psarakis

Generative adversarial networks (GANs) are designed with the help of min-max optimization problems that are solved with stochastic gradient-type algorithms which are known to be non-robust. In this work we revisit a non-adversarial method based on kernels which relies on a pure minimization problem and propose a simple stochastic gradient algorithm for the c

Yipeng Qin, Niloy Mitra, Peter Wonka

Despite the success of Lipschitz regularization in stabilizing GAN training, the exact reason of its effectiveness remains poorly understood. The direct effect of $K$-Lipschitz regularization is to restrict the $L2$-norm of the neural network gradient to be smaller than a threshold $K$ (e.g., $K=1$) such that $\|\nabla f\| \leq K$. In this work, we uncover a

Xin Wen, Dongfan Li, Kai Tan, Qian Deng

Because of the flexoelectric effect, dielectric materials usually polarize in response to a strain gradient. Soft materials are good candidates for developing large strain gradient because of their good deformability. However, they always suffer from lower flexoelectric coefficients compared to ceramics. In this work, a flexoelectric-like effect is introduce

C. B. D'Andrea, M. Smith, M. Sullivan, R. C. Nichol

We present spectroscopy from the first three seasons of the Dark Energy Survey Supernova Program (DES-SN). We describe the supernova spectroscopic program in full: strategy, observations, data reduction, and classification. We have spectroscopically confirmed 307 supernovae, including 251 type Ia supernovae (SNe Ia) over a redshift range of $0.017 < z < 0.85

George Raptis

A d\'evissage-type theorem in algebraic $K$-theory is a statement that identifies the $K$-theory of a Waldhausen category $\mathscr{C}$ in terms of the $K$-theories of a collection of Waldhausen subcategories of $\mathscr{C}$ when a d\'evissage condition about the existence of appropriate finite filtrations is satisfied. We distinguish between d\'evissage th

Gianmichele Di Matteo

In 2011 Enders, M\"{u}ller and Topping showed that any blow up sequence of a Type I Ricci flow near a singular point converges to a non-trivial gradient Ricci soliton, leading them to conclude that for such flows all reasonable definitions of singular points agree with each other. We prove the analogous result for the harmonic Ricci flow, generalizing in par

Amina Houari

Biclustering is an unsupervised data mining technique that aims to unveil patterns (biclusters) from gene expression data matrices. In the framework of this thesis, we propose new biclustering algorithms for microarray data. The latter is done using data mining techniques. The objective is to identify positively and negatively correlated biclusters. This the

Jonatan Grimm, Katja Herzog, Florian Rist, Anna Kicherer

In (grapevine) breeding programs and research, periodic phenotyping and multi-year monitoring of different grapevine traits, like growth or yield, is needed especially in the field. This demand imply objective, precise and automated methods using sensors and adaptive software. This work presents a proof-of-concept analyzing RGB images of different growth sta

Endre Csóka, Viktor Harangi, Bálint Virág

Shearer's inequality bounds the sum of joint entropies of random variables in terms of the total joint entropy. We give another lower bound for the same sum in terms of the individual entropies when the variables are functions of independent random seeds. The inequality involves a constant characterizing the expansion properties of the system. Our results ge

Bozena Czerny, Jian-Min Wang, Pu Du, Krzysztof Hryniewicz

Most results of the reverberation monitoring of active galaxies showed a universal scaling of the time delay of the Hbeta emission region with the monochromatic flux at 5100 A, with very small dipersion. Such a scaling favored the dust-based formation mechanism of the Broad Line Region (BLR). Recent reverberation measurements showed that actually a significa

Zi Wang, Beomjoon Kim, Leslie Pack Kaelbling

Bayesian optimization usually assumes that a Bayesian prior is given. However, the strong theoretical guarantees in Bayesian optimization are often regrettably compromised in practice because of unknown parameters in the prior. In this paper, we adopt a variant of empirical Bayes and show that, by estimating the Gaussian process prior from offline data sampl

Abbas Rahimi, Tony F. Wu, Haitong Li, Jan M. Rabaey

One viable solution for continuous reduction in energy-per-operation is to rethink functionality to cope with uncertainty by adopting computational approaches that are inherently robust to uncertainty. It requires a novel look at data representations, associated operations, and circuits, and at materials and substrates that enable them. 3D integrated nanotec

Yan Wu, Greg Wayne, Karol Gregor, Timothy Lillicrap

A central challenge faced by memory systems is the robust retrieval of a stored pattern in the presence of interference due to other stored patterns and noise. A theoretically well-founded solution to robust retrieval is given by attractor dynamics, which iteratively clean up patterns during recall. However, incorporating attractor dynamics into modern deep

Rodrigo de Freitas Gabert, Rodrigo da Silva Rodrigues

In this paper, we study the existence of three solutions for a Kirchhoff equation involving the nonlocal fractional p-Laplacian considering Sobolev and Hardy nonlinearities at subcritical and critical growths. The proof is based on Mountain Pass Theorem, Ekeland's variational principle and constrained minimization in Nehari sets.

Sanjiv K. Tiwari, Ronald L. Moore, Bart De Pontieu, Theodore D. Tarbell

A recent study using {\it Hinode} (SOT/FG) data of a sunspot revealed some unusually large penumbral jets that often repeatedly occurred at the same locations in the penumbra, namely at the tail of a penumbral filament or where the tails of multiple penumbral filaments converged. These locations had obvious photospheric mixed-polarity magnetic flux in \NaI\

Madeleine Elyze, Alexander Guterman, Ralph Morrison, Klemen Šivic

The commuting variety of matrices over a given field is a well-studied object in linear algebra and algebraic geometry. As a set, it consists of all pairs of square matrices with entries in that field that commute with one another. In this paper we generalise the commuting variety by using the commuting distance of matrices. We show that over an algebraicall

Eliza M. Ferreira, Armando G. M. Neves

We study fixation probabilities for the Moran stochastic process for the evolution of a population with three or more types of individuals and frequency-dependent fitnesses. Contrarily to the case of populations with two types of individuals, in which fixation probabilities may be calculated by an exact formula, here we must solve a large system of linear eq

Thomas P Prescott, Ruth E Baker

A vital stage in the mathematical modelling of real-world systems is to calibrate a model's parameters to observed data. Likelihood-free parameter inference methods, such as Approximate Bayesian Computation, build Monte Carlo samples of the uncertain parameter distribution by comparing the data with large numbers of model simulations. However, the computatio

Vangelis Bacoyannis, Vacslav Glukhov, Tom Jin, Jonathan Kochems

We outline the idiosyncrasies of neural information processing and machine learning in quantitative finance. We also present some of the approaches we take towards solving the fundamental challenges we face.

Faustino Prieto, José María Sarabia, Enrique Calderín-Ojeda

In this paper, the nonlinear distribution of employment across Spanish municipalities is analyzed. In addition, we explore the properties of the family of generalized power law (GPL) distributions, and test its adequacy for modelling employment data. The hierarchical structure of the GPL family that includes the hierarchy of Pareto (power law) distributions

Thomas Le Goff, Alphée Michelot

The actin cytoskeleton is composed of multiple networks which are specialized for several processes such as cell motility or cell division. Each of these networks are composed of organized actin microfilaments which are decorated with specific sets of actin binding proteins (ABPs). The molecular mechanisms guiding ABPs to specific actin networks are still po

Pavel Jiroušek, Alexander Vikman

We introduce a new Weyl-invariant and generally-covariant vector-tensor theory with higher derivatives. This theory can be induced by extending the mimetic construction to vector fields of conformal weight four. We demonstrate that in gauge-invariant variables this novel theory reduces to the Henneaux-Teitelboim description of the unimodular gravity. Hence,

V. L. Díaz-Melián, L. A. Rodríguez, F. Pedroso-Camejo, J. Mieres

Smartphones may be seen as miniature toolboxs to perform Physics experiments. In this paper, we present three different "optics workbenches" mainly based on the light meter of a smartphone. One is aimed at the precise study of Malus law and other effects associated to linearly polarized light, the second allows quantifying the light intensity distribution of

Jakub Jadwiszczak, Darragh Keane, Pierce Maguire, Conor P. Cullen

Two-dimensional layered semiconductors have recently emerged as attractive building blocks for next-generation low-power non-volatile memories. However, challenges remain in the controllable sub-micron fabrication of bipolar resistively switching circuit components from these novel materials. Here we report on the scalable experimental realisation of lateral

E. Cancellieri, H. Schomerus

A main objective of topological photonics is the design of disorder-resilient optical devices. Many prospective applications would benefit from nonlinear effects, which not only are naturally present in real systems but also are needed for switching in computational processes, while the underlying particle interactions are a key ingredient for the manifestat

A. Balmaseda, J. M. Pérez-Pardo

We present a scheme for controlling the state of a quantum system by modifying the boundary conditions. This constitutes an infinite-dimensional control problem. We provide conditions for the existence of solutions of the dynamics and prove that this system is approximately controllable.

Le-Yu Chen, Sokbae Lee

We consider a high dimensional binary classification problem and construct a classification procedure by minimizing the empirical misclassification risk with a penalty on the number of selected features. We derive non-asymptotic probability bounds on the estimated sparsity as well as on the excess misclassification risk. In particular, we show that our metho

Pavel V. Kuptsov, Anna V. Kuptsova

Dimension of an inertial manifold for a chaotic attractor of spatially distributed system is estimated using autoencoder neural network. The inertial manifold is a low dimensional manifold where the chaotic attractor is embedded. The autoencoder maps system state vectors onto themselves letting them pass through an inner state with a reduced dimension. The t

Steve Alpern, Viciano Lee

Shmuel Gal and Jerome Casas have recently introduced a game theoretic model that combines search and pursuit by a predator for a prey animal. The prey (hider) can hide in a finite number of locations. The predator (searcher) can inspect any k of these locations. If the prey is not in any of these, the prey wins. If the prey is found at an inspected location,

Dipayan Chakraborty, Florent Foucaud, Aline Parreau, Annegret K. Wagler

The problems of determining the minimum-sized \emph{identifying}, \emph{locating-dominating} and \emph{open locating-dominating codes} of an input graph are special search problems that are challenging from both theoretical and computational viewpoints. In these problems, one selects a dominating set $C$ of a graph $G$ such that the vertices of a chosen subs

Julien Le Gouët, Jérémy Oudin, Philippe Perault, Alaeddine Abbes

The influence of low temperatures on the performance of a high-power single-frequency fiber laser amplifier is evaluated with a numerical simulation. Cooling the fiber can allow to take advantage of both higher damping of the acoustic waves in the silica glass, and higher laser efficiency. We first report on the measurement of the stimulated Brillouin scatte

The CEPC Study Group

The Circular Electron Positron Collider (CEPC) is a large international scientific facility proposed by the Chinese particle physics community to explore the Higgs boson and provide critical tests of the underlying fundamental physics principles of the Standard Model that might reveal new physics. The CEPC, to be hosted in China in a circular underground tun

Francisco Navarro-Lerida, Eugen Radu, D. H. Tchrakian

The question of the dependence of the topological charge $q$ of a gauged Skyrmion, on the gauge field, is studied quantitatively. Two examples, both gauged with $SO(2)$ are studied and contrasted: i) The $O(3)$ model in $2+1$ dimensions, and ii) The $O(4)$ model in $3+1$ dimensions. In case i), where the (usual) Chern-Simons (CS) term is present, the value o

Pedro Augusto Franco Pinheiro Moreira, Roberto Gomes de Aguiar Veiga, Maurice de Koning

Using molecular dynamics simulations we compute the elastic constants of ice I$_h$ for a set of 8 frequently used semi-empirical potentials for water, namely the rigid-molecule SPC/E, TIP4P, TIP4P2005, TIP4P/Ice and TIP5P models, the flexible-molecule qTIP4P/Fw and SPC/Fw models and the coarse-grained atomic mW potential. In quantitative terms, the mW descri

Claire Bourquard, Nicolas Noiray

Acoustic dampers are efficient and cost-effective means for suppressing thermoacoustic instabilities in combustion chambers. However, their design and the choice of their purging air mass flow is a challenging task, when one aims at ensuring thermoacoustic stability after their implementation. In the present experimental and theoretical study, Helmholtz (HH)

John Bourke

Algebraic injectivity was introduced to capture homotopical structures like algebraic Kan complexes. But at a much simpler level, it allows one to describe sets with operations subject to no equations. If one wishes to add equations (or operations of greater complexity) then it is natural to consider iterated algebraic injectives, which we introduce and stud

V. Sposini, A. V. Chechkin, F. Seno, G. Pagnini

A considerable number of systems have recently been reported in which Brownian yet non-Gaussian dynamics was observed. These are processes characterised by a linear growth in time of the mean squared displacement, yet the probability density function of the particle displacement is distinctly non-Gaussian, and often of exponential (Laplace) shape. This appar

Gerhard Pfister, Andreas Steenpass

In this paper we describe the method which we applied to successfully compute the primary decomposition of a certain ideal coming from applications in combinatorial algebra and algebraic statistics regarding conditional independence statements with hidden variables. While our method is based on the algorithm for primary decomposition by Gianni, Trager and Za

Dawid Wisniewski, Jedrzej Potoniec, Agnieszka Lawrynowicz, C. Maria Keet

Competency Questions (CQs) are natural language questions outlining and constraining the scope of knowledge represented by an ontology. Despite that CQs are a part of several ontology engineering methodologies, we have observed that the actual publication of CQs for the available ontologies is very limited and even scarcer is the publication of their respect

Cristian Ferreyra, Wilson Román Acevedo, Ralph Gay, Diego Rubi

Redox-based memristive devices are among the alternatives for the next generation of non volatile memories, but also candidates to emulate the behavior of synapses in neuromorphic computing devices. It is nowadays well established that the motion of oxygen vacancies (OV) at the nanoscale is the key mechanism to reversibly switch metal/insulator/metal structu

Ruaridh. R Macdonald, R. Scott Kemp

International verification of nuclear warheads is a practical problem in which the protection of secret warhead information is of paramount importance. We propose a measure that would enable a weapon owner to evaluate the privacy of a proposed protocol in a technology-neutral fashion. We show the problem is reducible to `natural' and `corrective' learning. T

Marcus Webb, Vincent Coppé, Daan Huybrechs

Fourier series approximations of continuous but nonperiodic functions on an interval suffer the Gibbs phenomenon, which means there is a permanent oscillatory overshoot in the neighbourhoods of the endpoints. Fourier extensions circumvent this issue by approximating the function using a Fourier series which is periodic on a larger interval. Previous results

Tullio Ceccherini-Silberstein, Fabio Scarabotti, Filippo Tolli

In this work, we study multiplicity-free induced representations of finite groups. We analyze in great detail the structure of the Hecke algebra corresponding to the commutant of an induced representation and then specialize to the multiplicity-free case. We then develop a suitable theory of spherical functions that, in the case of induction of the trivial r

Erixhen Sula, Michael Gastpar, Gerhard Kramer

The feedback sum-rate capacity is established for the symmetric $J$-user Gaussian multiple-access channel (GMAC). The main contribution is a converse bound that combines the dependence-balance argument of Hekstra and Willems (1989) with a variant of the factorization of a convex envelope of Geng and Nair (2014). The converse bound matches the achievable sum-

Markus Pössel

This article presents a simple model that reproduces key concepts of modern cosmology within the framework of special relativity, at a level that is suitable for an undergraduate or high school setting. The model includes cosmic expansion governed by a universal scale factor, the Hubble relation, proper distances between galaxies and the associated recession

Rasa Muller, Sander von Benda-Beckmann, Ed Doppenberg, Robert Lahmann

With the KM3NeT experiment, which is presently under construction in the Mediterranean Sea, a new neutrino telescope will be installed to study both the neutrino properties as well as the cosmic origin of these particles. To do so, about 6000 optical modules will be installed in the abyss of the Mediterranean Sea to observe the Cherenkov radiation induced by

Gavin Ramsay

Blue Large Amplitude Pulsators (BLAPs) are blue stars showing high amplitude (>0.2 mag) pulsations on a timescale of a few tens of mins. They form a new class of variable star recently discovered using OGLE data. It has lead to a number of investigations searching for the origin of these pulsations. This short study presents the Gaia DR2 data of ten BLAPs wh

Jia Li, Junjie Wu, Anlin Zheng, Yafei Song

Segmenting primary objects in a video is an important yet challenging problem in computer vision, as it exhibits various levels of foreground/background ambiguities. To reduce such ambiguities, we propose a novel formulation via exploiting foreground and background context as well as their complementary constraint. Under this formulation, a unified objective

Thomas Nitsche, Tobias Geib, Christoph Stahl, Lennart Lorz

We study topological phenomena of quantum walks by implementing a novel protocol that extends the range of accessible properties to the eigenvalues of the walk operator. To this end, we experimentally realise for the first time a split-step quantum walk with decoupling, which allows for investigating the effect of a bulk-boundary while realising only a singl

Jonas Wätzel, Jamal Berakdar

Spin Hall effect, one of the cornerstones in spintronics refers to the emergence of an imbalance in the spin density transverse to a charge flow in a sample under voltage bias. This study points to a novel way for an ultrafast generation and tuning of a unidirectional nonlinear spin Hall current by means of subpicosecond laser pulses of optical vortices. Whe

Athanasios G. Tzikas, Piero Nicolini, Jonas Mureika, Bernard Carr

We investigate the spontaneous creation of primordial black holes in a lower-dimensional expanding early universe. We use the no-boundary proposal to construct instanton solutions for both the background and a black hole nucleated inside this background. The resulting creation rate could lead to a significant population of primordial black holes during the l

Robert Hesse, Alexandra Neamtu

We consider infinite-dimensional parabolic rough evolution equations. Using regularizing properties of analytic semigroups we prove global-in-time existence of solutions and investigate random dynamical systems for such equations.

P. Fibla, S. Bovino, R. Riaz, V. B. Díaz

We present here a three-dimesional hydrodynamical simulation for star formation. Our aim is to explore the effect of the metal-line cooling on the thermodynamics of the star-formation process. We explore the effect of changing the metallicty of the gas from $Z/Z_{\odot}=10^{-4}$ to $Z/Z_{\odot}=10^{-2}$. Furthermore, we explore the implications of using the

Jiang Zhang, Yuanqing Xia, Ganghui Shen

Autonomous path planning algorithms are significant to planetary exploration rovers, since relying on commands from Earth will heavily reduce their efficiency of executing exploration missions. This paper proposes a novel learning-based algorithm to deal with global path planning problem for planetary exploration rovers. Specifically, a novel deep convolutio

Fernando Soldevila, Jonathan Dong, Enrique Tajahuerce, Sylvain Gigan

Raman microscopy is a powerful method combining non-invasiveness with no special sample preparation. Because of this remarkable simplicity, it has been widely exploited in many fields, ranging from life and materials sciences, to engineering. Notoriously, due to the required imaging speeds for bio-imaging, it has remained a challenge how to use this techniqu

Meghdad Saeedian, Maxi San Miguel, Raul Toral

We present a stochastic dynamics model of coupled evolution for the binary states of nodes and links in a complex network. In the context of opinion formation node states represent two possible opinions and link states a positive or negative relation. Dynamics proceeds via node and link state update towards pairwise satisfactory relations in which nodes in t

Cong Xue

In this paper we prove that the cohomology groups with compact support of stacks of shtukas are modules of finite type over a Hecke algebra. As an application, we extend the construction of excursion operators, defined by V. Lafforgue on the space of cuspidal automorphic forms, to the space of automorphic forms with compact support. This gives the Langlands

Yao Zhao, Dedi Wang, Zhiwen Zhang, Ying Lu

The biological processes that execute complex multiple functions, such as cell cycle, must ensure the order of sequential events and keep the dynamic robustness against various fluctuations. Here, we examine the dynamic mechanism and the fundamental structure to achieve these properties in the cell-cycle process of budding yeast Saccharomyces cerevisiae. We

Michael Falk, Simone Padoan, Florian Wisheckel

This paper reviews generalized Pareto copulas (GPC), which turn out to be a key to multivariate extreme value theory. Any GPC can be represented in an easy analytic way using a particular type of norm on $\mathbb{R}^d$, called $D$-norm. The characteristic property of a GPC is its exceedance stability. GPC might help to end the debate: What is a multivariate

B. F. L. Ward, S. Jadach, Z. Was, S. A. Yost

${\cal KK}$MC-hh is a precision event-generator for Z production and decay in hadronic collisions, which applies amplitude-level resummation to both initial and final state photon radiation, including perturbative residuals exact through ${\cal O}(\alpha^2L)$, together with exact ${\cal O}(\alpha)$ EW matrix element corrections. We present some comparisons t

Semin Kwak, Joohwan Chun, Sung Hyuck Ye

A conventional monopulse radar system uses three beams; sum beam, elevation difference beam and azimuth difference beam, which require different layers of weights to synthesize each beam independently. Since the multi-layer structure increases hardware complexity, many simplified structures based on a single layer of weights have been suggested. In this work

Rik Versendaal

We provide a direct proof of Cram\'er's theorem for geodesic random walks in a complete Riemannian manifold $(M,g)$. We show how to exploit the vector space structure of the tangent spaces to study large deviation properties of geodesic random walks in $M$. Furthermore, we reveal the geometric obstructions one runs into and overcome these by providing Taylor

Mateusz Snamina, Emil J. Zak

In the present paper we show a link between bistochastic quantum channels and classical maps. The primary goal of this work is to analyse the multiplicative structure of the Birkhoff polytope of order 3 (the simplest non-trivial case). A suitable complex parametrization of the Birkhoff polytope is proposed, which reveals several its symmetries and characteri

Takahiro Nishimichi, Masahiro Takada, Ryuichi Takahashi, Ken Osato

We perform an ensemble of $N$-body simulations with $2048^3$ particles for 101 flat $w$CDM cosmological models sampled based on a maximin-distance Sliced Latin Hypercube Design. By using the halo catalogs extracted at multiple redshifts in the range of $z=[0,1.48]$, we develop Dark Emulator, which enables fast and accurate computations of the halo mass funct

Vadim V. Brazhkin, Vladimir L. Solozhenko

Reports published in the last 25 years on the synthesis of carbon-based materials significantly superior to diamond in hardness and elastic properties have been critically examined, and three groups of recently appearing myths have been analyzed. The first group concerns the possibility of producing materials with bulk moduli much higher than that of diamond

Santanu Mondal, Sandip K Chakrabarti

We report a detailed spectral study of Swift~J1357.2-0933 low-mass X-ray binary during its 2017 outburst using {\it Swift} and {\it NuSTAR} observations. We fit the data with two component advective flow (TCAF) model and power-law model. We observe that the source is in hard state during the outburst, where the size of the Compton cloud changes significantly

Mahesh Kumar Mulimani, Alok Ranjan Nayak, Rahul Pandit

We compare and contrast spiral- and scroll-wave dynamics in five different mathematical models for cardiac tissue. The first is the TP06 model, due to ten Tusscher and Panfilov, which is based on the Hodgkin-Huxley formalism; the remaining four are Markov-state models, MM1 WT and MM2 WT, for the wild-type (WT) Na channel, and MM1 MUT and MM2 MUT, for the mut

Sudharshan Chandra Babu, Shishira R Maiya, Sivasankar Elango

Diabetic Retinopathy is the leading cause of blindness in the world. At least 90\% of new cases can be reduced with proper treatment and monitoring of the eyes. However, scanning the entire population of patients is a difficult endeavor. Computer-aided diagnosis tools in retinal image analysis can make the process scalable and efficient. In this work, we foc

Vijay Balasubramanian, Niko Jokela, Arttu Pönni, Alfonso V. Ramallo

We use holographic methods to characterize the RG flow of quantum information in a Chern-Simons theory coupled to massive fermions. First, we use entanglement entropy and mutual information between strips to derive the dimension of the RG-driving operator and a monotonic c-function. We then display a scaling regime where, unlike in a CFT, the mutual informat

Yuanjun Jin, Zhongjia Chen, Bowen Xia, Yujun Zhao

The nontrivial band gap plays a critical role in quantum anomalous Hall (QAH) insulators. In this work, we propose that the intrinsic QAH phase with sizable band gaps up to 367 meV is achieved in two-dimensional hexagonal organometallic frameworks (HOMFs). Based on first-principles calculations and effective model analysis, we uncover that these large band g

Y. J. Jin, Z. J. Chen, B. W. Xia, Y. J. Zhao

Carbon, a basic versatile element in our universe, exhibits rich varieties of allotropic phases, most of which possess promising nontrivial topological fermions. In this work, we identify a distinct topological phonon phase in a realistic carbon allotrope with a body-centered cubic structure, termed bcc-C$_{8}$. We show by symmetry arguments and effective mo