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Jun 29, 2018
06/18

by
Jianfeng Wu; Jerome A. Orosz; Jeffrey E. McClintock; Imran Hasan; Charles D. Bailyn; Lijun Gou; Zihan Chen

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The optical counterpart of the black-hole soft X-ray transient Nova Muscae 1991 has brightened by $\Delta{V}\approx0.8$ mag since its return to quiescence 23 years ago. We present the first clear evidence that the brightening of soft X-ray transients in quiescence occurs at a nearly linear rate. This discovery, and our precise determination of the disk component of emission obtained using our $simultaneous$ photometric and spectroscopic data, have allowed us to identify and accurately model...

Topics: Astrophysics, High Energy Astrophysical Phenomena, Solar and Stellar Astrophysics

Source: http://arxiv.org/abs/1601.00616

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1.0

Jun 26, 2018
06/18

by
Charith S. Peris; Saeqa D. Vrtilek; James F. Steiner; Jan M. Vrtilek; Jianfeng Wu; Jeffrey E. McClintock; Penelope Longa-Peña; Danny Steeghs; Paul Callanan; Luis C. Ho; Jerome A. Orosz; Mark T. Reynolds

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We present a spectroscopic analysis of the black hole binary Nova Muscae 1991 in quiescence using data obtained in 2009 with MagE on the Magellan Clay telescope and in 2010 with IMACS on the Magellan Baade telescope at the Las Campanas Observatory. Emission from the disc is observed in H alpha, H beta and Ca II (8662 A). A prominent hotspot is observed in the Doppler maps of all three emission lines. The existence of this spot establishes ongoing mass transfer from the donor star in 2009-2010...

Topics: High Energy Astrophysical Phenomena, Astrophysics

Source: http://arxiv.org/abs/1502.06650

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0.0

Jun 29, 2018
06/18

by
Zihan Chen; Lijun Gou; Jeffrey E. McClintock; James F. Steiner; Jianfeng Wu; Weiwei Xu; Jerome Orosz; Yanmei Xiang

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The bright soft X-ray transient Nova Muscae 1991 was intensively observed during its entire 8-month outburst using the Large Area Counter (LAC) onboard the Ginga satellite. Recently, we obtained accurate estimates of the mass of the black hole primary, the orbital inclination angle of the system, and the distance. Using these crucial input data and Ginga X-ray spectra, we have measured the spin of the black hole using the continuum-fitting method. For four X-ray spectra of extraordinary quality...

Topics: Astrophysics, High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1601.00615

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2.0

Jun 25, 2018
06/18

by
Jianfeng Wu; Jerome A. Orosz; Jeffrey E. McClintock; Danny Steeghs; Penelope Longa-Pena; Paul J. Callanan; Lijun Gou; Luis C. Ho; Peter G. Jonker; Mark T. Reynolds; Manuel A. P. Torres

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We present a dynamical study of the Galactic black hole binary system Nova Muscae 1991 (GS/GRS 1124-683). We utilize 72 high resolution Magellan Echellette (MagE) spectra and 72 strictly simultaneous V-band photometric observations; the simultaneity is a unique and crucial feature of this dynamical study. The data were taken on two consecutive nights and cover the full 10.4-hour orbital cycle. The radial velocities of the secondary star are determined by cross-correlating the object spectra...

Topics: High Energy Astrophysical Phenomena, Astrophysics, Solar and Stellar Astrophysics, Astrophysics

Source: http://arxiv.org/abs/1501.00982

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1.0

Jun 28, 2018
06/18

by
Nathan Fox

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In 1991, Solomon Golomb discovered a quasilinear solution to Hofstadter's Q-recurrence. In this paper, we construct eventual quasipolynomial solutions of all positive degrees to Hofstadter's recurrence.

Topics: Combinatorics, Number Theory, Mathematics

Source: http://arxiv.org/abs/1511.06484

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0.0

Jun 28, 2018
06/18

by
Ali Akbulut; Vagif Guliyev; Takahiro Noi; Yoshihiro Sawano

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The generalized Morrey space was defined independetly by T. Mizuhara 1991 and E. Nakai in 1994. Generalized Morrey space ${\mathcal M}_{p,\phi}({\mathbb R}^n)$ is equipped with a parameter $0

Topics: Functional Analysis, Mathematics

Source: http://arxiv.org/abs/1511.02020

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2.0

Jun 28, 2018
06/18

by
Lauri Loiskekoski; Günter M. Ziegler

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We show that by cutting off the vertices and then the edges of neighborly cubical polytopes, one obtains simple 4-dimensional polytopes with n vertices such that all separators of the graph have size at least $\Omega(n/\log^{3/2}n)$. This disproves a conjecture by Kalai from 1991/2004.

Topics: Combinatorics, Metric Geometry, Mathematics

Source: http://arxiv.org/abs/1510.00511

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3.0

Jun 27, 2018
06/18

by
Michele Rossi; Lea Terracini

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The present paper is devoted to generalizing, inside the class of projective toric varieties, the classification \cite{Batyrev91}, performed by Batyrev in 1991 for smooth complete toric varieties, to the singular $\Q$--factorial case. Moreover, in the first part of the paper the Kleinschmidt classification of smooth complete toric varieties of Picard number 2 \cite{Kleinschmidt} is revised.

Topics: Algebraic Geometry, Mathematics

Source: http://arxiv.org/abs/1504.06515

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0.0

Jun 26, 2018
06/18

by
Luisa Allgaier; Heinz Weisshaupt

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We settle the first unsolved case of a problem of P. M. Gruber, asked by him in 1991, namely, to investigate the homomorphisms from the lattice of convex bodies of ${\mathbb{E}}^c$ to the lattice of convex bodies of ${\mathbb{E}}^d$ for $c

Topics: Mathematics, Metric Geometry

Source: http://arxiv.org/abs/1501.05635

2
2.0

Jun 27, 2018
06/18

by
Y. Suhov; S. Yasaei Sekeh; I. Stuhl

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We produce a series of results extending information-theoretical inequalities (discussed by Dembo--Cover--Thomas in 1989-1991) to a weighted version of entropy. The resulting inequalities involve the Gaussian weighted entropy; they imply a number of new relations for determinants of positive-definite matrices.

Topics: Information Theory, Computing Research Repository, Mathematics

Source: http://arxiv.org/abs/1505.01753

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0.0

Jun 28, 2018
06/18

by
Basudeb Datta; Soumen Sarkar

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Quasitoric manifolds, introduced by M. Davis and T. Januskiewicz in 1991, are topological generalizations of smooth complex projective spaces. In 1992, Banchoff and K\"uhnel constructed a 10-vertex equilibrium triangulations of $\CP^2$. We generalize this construction for quasitoric manifolds and construct some equilibrium triangulations of $4$-dimensional quasitoric manifolds. In some cases, our constructions give vertex minimal equilibrium triangulations.

Topics: Mathematics, Geometric Topology

Source: http://arxiv.org/abs/1507.07071

2
2.0

Jun 28, 2018
06/18

by
Pierre Charbit; Irena Penev; Stéphan Thomassé; Nicolas Trotignon

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We prove that there exist perfect graphs of arbitrarily large clique-chromatic number. These graphs can be obtained from cobipartite graphs by repeatedly gluing along cliques. This negatively answers a question raised by Duffus, Sands, Sauer, and Woodrow in [Two-coloring all two-element maximal antichains, J. Combinatorial Theory, Ser. A, 57 (1991), 109-116].

Topics: Combinatorics, Mathematics

Source: http://arxiv.org/abs/1506.08628

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3.0

Jun 27, 2018
06/18

by
R. B. Paris

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In 1991, Ursell gave a strong form of Watson's lemma for the Laplace integral \[\int_0^\infty e^{-xt}f(t)\,dt\qquad (x\rightarrow+\infty) \] in which the amplitude function $f(t)$ is regular at the origin and possesses a Maclaurin expansion valid in $0\leq t\leq R$. He showed that if the asymptotic series for the integral as $x\rightarrow+\infty$ is truncated after $rx$ terms, where $0

Topics: Mathematics, Classical Analysis and ODEs

Source: http://arxiv.org/abs/1505.06905

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0.0

Jun 28, 2018
06/18

by
Youngsik Huh; Seungsang Oh

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In 1991, Negami found an upper bound on the stick number $s(K)$ of a nontrivial knot $K$ in terms of the minimal crossing number $c(K)$ of the knot which is $s(K) \leq 2 c(K)$. In this paper we improve this upper bound to $s(K) \leq \frac{3}{2} (c(K)+1)$. Moreover if $K$ is a non-alternating prime knot, then $s(K) \leq \frac{3}{2} c(K)$.

Topics: Mathematics, Geometric Topology

Source: http://arxiv.org/abs/1512.03592

3
3.0

Jun 27, 2018
06/18

by
Minmin Wang

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By computations on generating functions, Szekeres proved in 1983 that the law of the diameter of a uniformly distributed rooted labelled tree with n vertices, rescaled by a factor n^{1/2} , converges to a distribution whose density is explicit. Aldous observed in 1991 that this limiting distribution is the law of the diameter of the Brownian tree. In our article, we provide a computation of this law which is directly based on the normalized Brownian excursion. Moreover, we provide an explicit...

Topics: Probability, Mathematics

Source: http://arxiv.org/abs/1503.05014

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0.0

Jun 28, 2018
06/18

by
Elbaz. I. Abouelmagd; S. M Elshaboury; H. H. Selim

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We offer an analytical study on the dynamics of a two-body problem perturbed by small post-Newtonian relativistic term. We prove that, while the angular momentum is not conserved, the motion is planar. We also show that the energy is subject to small changes due to the relativistic effect. We also offer a periodic solution to this problem, obtained by a method based of separation of timescales. We demonstrate that our solution is more general than the method developed in the book by Brumberg...

Topics: Astrophysics, Astrophysics of Galaxies, Solar and Stellar Astrophysics

Source: http://arxiv.org/abs/1512.03496

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9.0

Jun 26, 2018
06/18

by
Burcin Erocal; Oleksandr Motsak; Frank-Olaf Schreyer; Andreas Steenpass

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Based on Schreyer's algorithm (Schreyer, 1980, 1991; Berkesch and Schreyer, 2014), we present two refined algorithms for the computation of syzygies. The two main ideas of the first algorithm, called LiftHybrid, are the following: First, we may leave out certain terms of module elements during the computation which do not contribute to the result. These terms are called "lower order terms", see Definition 4.2. Second, we do not need to order the remaining terms of these module...

Topics: Mathematics, Commutative Algebra, Algebraic Geometry

Source: http://arxiv.org/abs/1502.01654

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3.0

Jun 28, 2018
06/18

by
Vladimir Lebedev

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We consider the class $C(T)$ of continuous real-valued functions on the circle. For certain classes of functions naturally characterised by the rapidity of decrease of Fourier coefficients we investigate whether it is possible to bring families of functions in $C(T)$ into these classes by a change of variable. This paper was originally published in Matematicheski\v{\i} Sbornik, 181:8 (1990), 1099--1113 (Russian). The English translation, published in Mathematics of the USSR, Sbornik, 70:2...

Topics: Mathematics, Classical Analysis and ODEs

Source: http://arxiv.org/abs/1508.06673

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0.0

Jun 26, 2018
06/18

by
Nareen Bamerni; Adem Kılıçman

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Our aim in this paper is to obtain necessary and sufficient conditions for weighted shift operators on the Hilbert spaces $\ell^{2}(\mathbb Z)$ and $\ell^{2}(\mathbb N)$ to be subspace-transitive, consequently, we show that the Herrero question (D. A. Herrero. Limits of hypercyclic and supercyclic operators, J. Funct. Anal., 99 (1991)179-190) holds true even on a subspace of a Hilbert space, i.e. there exists an operator $T$ such that both $T$ and $T^*$ are subspace-hypercyclic operators for...

Topics: Functional Analysis, Mathematics

Source: http://arxiv.org/abs/1501.02534

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2.0

Jun 26, 2018
06/18

by
Matthew Farrell; Lionel Levine

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We suggest a measure of "Eulerianness" of a finite directed graph and define a class of "coEulerian" graphs. These are the graphs whose Laplacian lattice is as large as possible. As an application, we address a question in chip-firing posed by Bjorner, Lovasz, and Shor in 1991, who asked for "a characterization of those digraphs and initial chip configurations that guarantee finite termination." Bjorner and Lovasz gave an exponential time algorithm in 1992. We show...

Topics: Mathematics, Combinatorics

Source: http://arxiv.org/abs/1502.04690

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0.0

Jun 28, 2018
06/18

by
Spyridon J. Hatjispyros; Theodoros Nicoleris; Stephen G. Walker

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A density estimation method in a Bayesian nonparametric framework is presented when recorded data are not coming directly from the distribution of interest, but from a length biased version. From a Bayesian perspective, efforts to computationally evaluate posterior quantities conditionally on length biased data were hindered by the inability to circumvent the problem of a normalizing constant. In this paper we present a novel Bayesian nonparametric approach to the length bias sampling problem...

Topics: Statistics Theory, Statistics, Mathematics

Source: http://arxiv.org/abs/1510.06307

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3.0

Jun 28, 2018
06/18

by
Roman Kononenko

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This study uses Vector Autoregression (VAR) Methodology as well as Vector Error Correction (VEC) Methodology to examine the existence and direction of causality between economic growth and IMF lending for Ukraine. The paper examines the IMF lending data for the period of 1991-2010. Robust empirical analysis indicates that IMF lending has a negative effect of on Ukraine's economic growth in the short term. Policy implications of this finding are that, despite short-run decline in economic...

Topics: Economics, Quantitative Finance

Source: http://arxiv.org/abs/1509.01741

0
0.0

Jun 27, 2018
06/18

by
Mu-Fa Chen

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The note begins with a short story on seeking for a practical sufficiency theorem for the uniqueness of time-continuous Markov jump processes, starting around 1977. The general result was obtained in 1985 for the processes with general state spaces. To see the sufficient conditions are sharp, a dual criterion for non-uniqueness was obtained in 1991. This note is restricted however to the discrete state space (then the processes are called $Q$-processes or Markov chains), for which the...

Topics: Probability, Mathematics

Source: http://arxiv.org/abs/1503.02119

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5.0

Jun 27, 2018
06/18

by
Yuki Susa

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We investigate the weak measurement experiment demonstrated by Ritchie et al. [N. W. M. Ritchie, J. G. Story, and R. G. Hulet, Phys. Rev. Lett. 66, 1107 (1991)] from the viewpoint of the statistical hypothesis testing for the weak-value amplification proposed by Susa and Tanaka [Y. Susa and S. Tanaka, Phys. Rev. A 92, 012112 (2015)]. We conclude that the weak-value amplification is a better method to determine whether the crystal used in the experiment is birefringent than the measurement...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1505.07199

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4.0

Jun 26, 2018
06/18

by
Toyohiro Tsurumaru; Tsubasa Ichikawa

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The squash operation, or the squashing model, is a useful mathematical tool for proving the security of quantum key distribution systems using practical (i.e., non-ideal) detectors. At the present, however, this method can only be applied to a limited class of detectors, such as the threshold detector of the Bennett-Brassard 1984 type. In this paper we generalize this method to include multi-partite measurements, such that it can be applied to a wider class of detectors. We demonstrate the...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1502.04802

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2.0

Jun 27, 2018
06/18

by
M. R. Feyereisen

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Weak values are average quantities,therefore investigating their associated variance is crucial in understanding their place in quantum mechanics. We develop the concept of a position-postselected weak variance of momentum as cohesively as possible, building primarily on material from Moyal (Mathematical Proceedings of the Cambridge Philosophical Society, Cambridge University Press, Cambridge, 1949) and Sonego (Found Phys 21(10):1135, 1991) . The weak variance is defined in terms of the Wigner...

Topics: Quantum Physics, Data Analysis, Statistics and Probability, Physics

Source: http://arxiv.org/abs/1503.07309

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3.0

Jun 28, 2018
06/18

by
Boris Beranger; Simone A. Padoan

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Extreme values of real phenomena are events that occur with low frequency, but can have a large impact on real life. These are, in many practical problems, high-dimensional by nature (e.g. Tawn, 1990; Coles and Tawn, 1991). To study these events is of fundamental importance. For this purpose, probabilistic models and statistical methods are in high demand. There are several approaches to modelling multivariate extremes as described in Falk et al. (2011), linked to some extent. We describe an...

Topics: Methodology, Statistics

Source: http://arxiv.org/abs/1508.05561

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6.0

Jun 27, 2018
06/18

by
Dan Arnon; Navindra Sharma

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Enterprise-scale systems such as those used for cloud computing require a scalable and highly available infrastructure. One crucial ingredient of such an infrastructure is the ability to replicate data coherently among a group of cooperating processes in the presence of process failures and group membership changes. The last few decades have seen prolific research into efficient protocols for such data replication. One family of such protocols are the virtually synchronous protocols. Virtually...

Topics: Computing Research Repository, Distributed, Parallel, and Cluster Computing

Source: http://arxiv.org/abs/1503.02241

5
5.0

Jun 27, 2018
06/18

by
A. A. Valverde; G. Bollen; M. Brodeur; R. A. Bryce; K. Cooper; M. Eibach; K. Gulyuz; C. Izzo; D. J. Morrissey; M. Redshaw; R. Ringle; R. Sandler; S. Schwarz; C. S. Sumithrarachchi; A. C. C. Villari

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We report the first direct measurement of the $^{14}\text{O}$ superallowed Fermi $\beta$-decay $Q_{EC}$-value, the last of the so-called "traditional nine" superallowed Fermi $\beta$-decays to be measured with Penning trap mass spectrometry. $^{14}$O, along with the other low-$Z$ superallowed $\beta$-emitter, $^{10}$C, is crucial for setting limits on the existence of possible scalar currents. The new ground state $Q_{EC}$ value, 5144.364(25) keV, when combined with the energy of the...

Topic: Nuclear Experiment

Source: http://arxiv.org/abs/1503.08124

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1.0

Jun 28, 2018
06/18

by
P. H. Lundow; I. A. Campbell

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The critical behaviors of the bimodal and Gaussian Ising spin glass (ISG) models in dimension four are studied through extensive numerical simulations, and from an analysis of high temperature series expansion (HTSE) data of Klein {\it et al.} (1991). The simulations include standard finite size scaling measurements, thermodynamic limit regime measurements, and analyses which provide estimates of critical exponents without any consideration of the critical temperature. The higher order HTSE...

Topics: Disordered Systems and Neural Networks, Condensed Matter

Source: http://arxiv.org/abs/1507.01965

4
4.0

Jun 27, 2018
06/18

by
Tomer Kotek; Helmut Veith; Florian Zuleger

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The finite satisfiability problem of monadic second order logic is decidable only on classes of structures of bounded tree-width by the classic result of Seese (1991). We prove the following problem is decidable: Input: (i) A monadic second order logic sentence $\alpha$, and (ii) a sentence $\beta$ in the two-variable fragment of first order logic extended with counting quantifiers. The vocabularies of $\alpha$ and $\beta$ may intersect. Output: Is there a finite structure which satisfies...

Topics: Logic in Computer Science, Computing Research Repository

Source: http://arxiv.org/abs/1505.06622

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0.0

Jun 28, 2018
06/18

by
Piotr Borowiecki; Michael Gentner; Christian Löwenstein; Dieter Rautenbach

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The independence number $\alpha(H)$ of a hypergraph $H$ is the maximum cardinality of a set of vertices of $H$ that does not contain an edge of $H$. Generalizing Shearer's classical lower bound on the independence number of triangle-free graphs (J. Comb. Theory, Ser. B 53 (1991) 300-307), and considerably improving recent results of Li and Zang (SIAM J. Discrete Math. 20 (2006) 96-104) and Chishti et al. (Acta Univ. Sapientiae, Informatica 6 (2014) 132-158), we show that $$\alpha(H)\geq...

Topics: Combinatorics, Mathematics

Source: http://arxiv.org/abs/1507.04323

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6.0

Jun 28, 2018
06/18

by
G. A. Leonov; N. V. Kuznetsov; N. A. Korzhemanova; D. V. Kusakin

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The exact Lyapunov dimension formula for the Lorenz system has been analytically obtained first due to G.A.Leonov in 2002 under certain restrictions on parameters, permitting classical values. He used the construction technique of special Lyapunov-type functions developed by him in 1991 year. Later it was shown that the consideration of larger class of Lyapunov-type functions permits proving the validity of this formula for all parameters of the system such that all the equilibria of the system...

Topics: Chaotic Dynamics, Dynamical Systems, Mathematics, Nonlinear Sciences

Source: http://arxiv.org/abs/1508.07498

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6.0

Jun 27, 2018
06/18

by
Margherita Disertori; Franz Merkl; Silke W. W. Rolles

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We study the nonlinear supersymmetric hyperbolic sigma model introduced by Zirnbauer in 1991. This model can be related to the mixing measure of a vertex- reinforced jump process. We prove that the two-point correlation function has a probabilistic interpretation in terms of connectivity in rooted random spanning forests. Using this interpretation, we dominate the two-point correlation function for general pinning, e.g. for uniform pinning, with the corresponding correlation function with...

Topics: Mathematics, Probability

Source: http://arxiv.org/abs/1506.01852

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2.0

Jun 28, 2018
06/18

by
Krishna Kumar Sabapathy

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We introduce a quantum-optical notion of nonclassicality that we call as the process output nonclassicality for multimode quantum channels. The motivation comes from an information-theoretic point of view and the emphasis is on the output states of a channel. We deem a channel to be `classical' if its outputs are always classical irrespective of the input, i.e., if the channel is nonclassicality breaking, and nonclassical otherwise. Our condition is stronger than the one considered by...

Topics: Quantum Physics, Optics, Physics

Source: http://arxiv.org/abs/1506.06706

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5.0

Jun 27, 2018
06/18

by
Christian Günther; Kai-Uwe Schmidt

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The problem of constructing polynomials with all coefficients $1$ or $-1$ and large merit factor (equivalently with small $L^4$ norm on the unit circle) arises naturally in complex analysis, condensed matter physics, and digital communications engineering. Most known constructions arise (sometimes in a subtle way) from difference sets, in particular from Paley and Singer difference sets. We consider the asymptotic merit factor of polynomials constructed from other difference sets, providing the...

Topics: Combinatorics, Information Theory, Computing Research Repository, Mathematics

Source: http://arxiv.org/abs/1503.05858

4
4.0

Jun 28, 2018
06/18

by
Mrinmoy Datta; Sudhir R. Ghorpade

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We consider the problem of determining the maximum number of common zeros in a projective space over a finite field for a system of linearly independent multivariate homogeneous polynomials defined over that field. There is an elaborate conjecture of Tsfasman and Boguslavsky that predicts the maximum value when the homogeneous polynomials have the same degree that is not too large in comparison to the size of the finite field. We show that this conjecture holds in the affirmative if the number...

Topics: Mathematics, Algebraic Geometry

Source: http://arxiv.org/abs/1507.03029

2
2.0

Jun 26, 2018
06/18

by
Daniel Chung; Leon Chan; Michael MacDonald; Nicholas Hutchins; Andrew Ooi

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We describe a fast direct numerical simulation (DNS) method that promises to directly characterise the hydraulic roughness of any given rough surface, from the hydraulically smooth to the fully rough regime. The method circumvents the unfavourable computational cost associated with simulating high-Reynolds-number flows by employing minimal-span channels (Jimenez & Moin 1991). Proof-of-concept simulations demonstrate that flows in minimal-span channels are sufficient for capturing the...

Topics: Physics, Fluid Dynamics

Source: http://arxiv.org/abs/1502.07043

2
2.0

Jun 28, 2018
06/18

by
Suyoung Choi; Hanchul Park

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A fundamental idea in toric topology is that classes of manifolds with well-behaved torus actions (simply, toric spaces) are classified by pairs of simplicial complexes and (non-singular) characteristic maps. The authors in their previous paper provided a new way to find all characteristic maps on a simplicial complex $K(J)$ obtainable by a sequence of wedgings from $K$. The main idea was that characteristic maps on $K$ theoretically determine all possible characteristic maps on a wedge of $K$....

Topics: Algebraic Topology, Mathematics

Source: http://arxiv.org/abs/1507.08306

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3.0

Jun 27, 2018
06/18

by
Ricardo A. Maronna; Victor J. Yohai

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We deal with the equivariant estimation of scatter and location for p-dimensional data, giving emphasis to scatter. It it important that the estimators possess both a high efficiency for normal data and a high resistance to outliers, that is, a low bias under contamination. The most frequently employed estimators are not quite satisfactory in this respect. The Minimum Volume Ellipsoid (MVE) and Minimum Covariance Determinant (MCD) estimators are known to have a very low efficiency. S-Estimators...

Topics: Statistics, Mathematics, Statistics Theory

Source: http://arxiv.org/abs/1504.03389

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3.0

Jun 28, 2018
06/18

by
P. H. Lundow; I. A. Campbell

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Ising spin glasses with bimodal and Gaussian near-neighbor interaction distributions are studied through numerical simulations. The non-self-averaging (normalized inter-sample variance) parameter $U_{22}(T,L)$ for the spin glass susceptibility (and for higher moments $U_{nn}(T,L)$) is reported for dimensions 2, 3, 4, 5 and 7. In each dimension $d$ the non-self-averaging parameters in the paramagnetic regime vary with the sample size L and the correlation length $\xi(T,L)$ as $U_{nn}(\beta,L) =...

Topics: Disordered Systems and Neural Networks, Condensed Matter

Source: http://arxiv.org/abs/1508.03368

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Jun 26, 2018
06/18

by
Matthias Mauch; Robert M. MacCallum; Mark Levy; Armand M. Leroi

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In modern societies, cultural change seems ceaseless. The flux of fashion is especially obvious for popular music. While much has been written about the origin and evolution of pop, most claims about its history are anecdotal rather than scientific in nature. To rectify this we investigate the US Billboard Hot 100 between 1960 and 2010. Using Music Information Retrieval (MIR) and text-mining tools we analyse the musical properties of ~17,000 recordings that appeared in the charts and...

Topics: Sound, Physics, Physics and Society, Computing Research Repository

Source: http://arxiv.org/abs/1502.05417

1
1.0

Jun 28, 2018
06/18

by
Deepak Bal; Louis DeBiasio

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Erd\H{o}s, Gy\'arf\'as, and Pyber (1991) conjectured that every $r$-colored complete graph can be partitioned into at most $r-1$ monochromatic components; this is a strengthening of a conjecture of Lov\'asz (1975) in which the components are only required to form a cover. An important partial result of Haxell and Kohayakawa (1995) shows that a partition into $r$ monochromatic components is possible for sufficiently large $r$-colored complete graphs. We start by extending Haxell and Kohayakawa's...

Topics: Combinatorics, Mathematics

Source: http://arxiv.org/abs/1509.09168

2
2.0

Jun 28, 2018
06/18

by
S. Molkov; A. Lutovinov; M. Falanga

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We have investigated the temporal variability of the X-ray flux measured from the high-mass Xray binary LMCX-4 on time scales from several tens of days to tens of years, i.e., exceeding considerably the orbital period (1.408 days). In particular, we have investigated the 30-day cycle of modulation of the X-ray emission from the source (superorbital or precessional variability) and refined the orbital period and its first derivative. We show that the precession period in the time interval...

Topics: High Energy Astrophysical Phenomena, Astrophysics

Source: http://arxiv.org/abs/1509.06739

1
1.0

Jun 26, 2018
06/18

by
Shuichi Hirahara

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We provide a general framework to remove short advice by formulating the following computational task for a function $f$: given two oracles at least one of which is honest (i.e. correctly computes $f$ on all inputs) as well as an input, the task is to compute $f$ on the input with the help of the oracles by a probabilistic polynomial-time machine, which we shall call a selector. We characterize the languages for which short advice can be removed by the notion of selector: a paddable language...

Topics: Computing Research Repository, Computational Complexity

Source: http://arxiv.org/abs/1502.07258

2
2.0

Jun 28, 2018
06/18

by
Qian Lin; Zhigen Zhao; Jun S. Liu

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We provide here a framework to analyze the phase transition phenomenon of slice inverse regression (SIR), a supervised dimension reduction technique introduced by \cite{Li:1991}. Under mild conditions, the asymptotic ratio $\rho= \lim p/n$ is the phase transition parameter and the SIR estimator is consistent if and only if $\rho= 0$. When dimension $p$ is greater than $n$, we propose a diagonal thresholding screening SIR (DT-SIR) algorithm. This method provides us with an estimate of the...

Topics: Statistics, Statistics Theory, Mathematics

Source: http://arxiv.org/abs/1507.03895

3
3.0

Jun 27, 2018
06/18

by
László Babai; John Wilmes

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We give a new bound on the parameter $\lambda$ (number of common neighbors of a pair of adjacent vertices) in a distance-regular graph $G$, improving and generalizing bounds for strongly regular graphs by Spielman (1996) and Pyber (2014). The new bound is one of the ingredients of recent progress on the complexity of testing isomorphism of strongly regular graphs (Babai, Chen, Sun, Teng, Wilmes 2013). The proof is based on a clique geometry found by Metsch (1991) under certain constraints on...

Topics: Data Structures and Algorithms, Combinatorics, Computing Research Repository, Discrete Mathematics,...

Source: http://arxiv.org/abs/1503.02746

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30

Jun 27, 2018
06/18

by
Hong Zhu; Zhi-Qiang Jiang; Sai-Ping Li; Wei-Xing Zhou

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Although technical trading rules have been widely used by practitioners in financial markets, their profitability still remains controversial. We here investigate the profitability of moving average (MA) and trading range break (TRB) rules by using the Shanghai Stock Exchange Composite Index (SHCI) from May 21, 1992 through December 31, 2013 and Shenzhen Stock Exchange Composite Index (SZCI) from April 3, 1991 through December 31, 2013. The $t$-test is adopted to check whether the mean returns...

Topics: Quantitative Finance, Trading and Market Microstructure, Statistical Finance

Source: http://arxiv.org/abs/1504.04254

3
3.0

Jun 26, 2018
06/18

by
Shun Tamura; Hisatoshi Yokoyama

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Drude weight ($D$) is a useful measure to distinguish a metal from an insulator. However, $D$ has not been justifiably estimated by the variation theory for long, since Millis and Coppersmith [Phys. Rev. B 43 (1991) 13770] pointed out that a variational wave function $\Psi_Q$, which includes the key ingredient (doublon-holon binding effect) for a Mott transition, yields a positive $D$ (namely metallic) even in the Mott-insulating regime. We argue that, to obtain a correct $D$, an imaginary part...

Topics: Strongly Correlated Electrons, Condensed Matter

Source: http://arxiv.org/abs/1502.04799

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1.0

Jun 28, 2018
06/18

by
A. A. Moiseev; M. Ajello; J. H. Buckley; R. Caputo; E. C. Ferrara; D. H. Hartmann; E. Hays; J. E. McEnery; J. W. Mitchell; R. Ojha; J. S. Perkins; J. L. Racusin; A. W. Smith; D. J. Thompson

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The gamma-ray energy range from a few hundred keV to a few hundred MeV has remained largely unexplored, mainly due to the challenging nature of the measurements, since the pi- oneering, but limited, observations by COMPTEL on the Compton Gamma-Ray Observatory (1991-2000). This energy range is a transition region between thermal and nonthermal processes, and accurate measurements are critical for answering a broad range of astrophysical questions. We are developing a MIDEX-scale wide-aperture...

Topics: High Energy Astrophysical Phenomena, Instrumentation and Methods for Astrophysics, Astrophysics

Source: http://arxiv.org/abs/1508.07349