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September 2013 arXiv papers — page 15

Showing 1,401–1,500 of 7,921 papers

  1. José R. Correa, Laurent Feuilloley, Pablo Pérez-Lantero, José A. Soto

    Finding a maximum independent set (MIS) of a given fam- ily of axis-parallel rectangles is a basic problem in computational geom- etry and combinatorics. This problem has attracted significant atten- tion since the sixties, when Wegner conjectured that the corresponding duality gap, i.e., the maximum possible ratio between the maximum independent set and the

  2. Romain Dujardin

    A holomorphic endomorphism f of CP^2 admits a Julia set J_1, defined as usual to be the locus of non-normality of its iterates, and a (typically) smaller Julia set J_2, which is essentially the closure of the set of repelling periodic orbits. The question has been raised whether J_1\J_2 is filled (possibly in a measure-theoretic sense) with "Fatou subvar

  3. Liangzhi Kou, Feiming Hu, Binghai Yan, Tim Wehling

    Graphene is the first model system of two-dimensional topological insulator (TI), also known as quantum spin Hall (QSH) insulator. The QSH effect in graphene, however, has eluded direct experimental detection because of its extremely small energy gap due to the weak spin-orbit coupling. Here we predict by ab initio calculations a giant (three orders of magni

  4. L. Cruz Rodriguez, A. Perez Martinez, H. Perez Rojas, E. Rodriguez Querts

    We study Faraday rotation in the quantum relativistic limit. Starting from the photon self-energy in the presence of a constant magnetic field the rotation of the polarization vector of a plane electromagnetic wave which travel along the fermion-antifermion gas is studied. The connection between Faraday Effect and Quantum Hall Effect (QHE) is discussed. The

  5. Vittorio Del Duca, Lance J. Dixon, Claude Duhr, Jeffrey Pennington

    We introduce a generating function for the coefficients of the leading logarithmic BFKL Green's function in transverse-momentum space, order by order in alpha_s, in terms of single-valued harmonic polylogarithms. As an application, we exhibit fully analytic azimuthal-angle and transverse-momentum distributions for Mueller-Navelet jet cross sections at ea

  6. Seonghak Kim, Baisheng Yan

    The Perona-Malik equation is an ill-posed forward-backward parabolic equation with major application in image processing. In this paper we study the Perona-Malik type equation and show that, in all dimensions, there exist infinitely many radial weak solutions to the homogeneous Neumann boundary problem for any smooth nonconstant radially symmetric initial da

  7. Audrey Galametz, Daniel Stern, Laura Pentericci, Carlos De Breuck

    We present the spectroscopic confirmation of a structure of galaxies surrounding the radio galaxy MRC0156-252 at z = 2.02. The structure was initially discovered as an overdensity of both near-infrared selected z > 1.6 and mid-infrared selected z > 1.2 galaxy candidates. We used the VLT/FORS2 multi-object spectrograph to target ~80 high-redshift galaxy candi

  8. A. G. Dias, P. R. D. Pinheiro, C. A. de S. Pires, P. S. Rodrigues da Silva

    We build a gauge model based on the SU(3)_c x SU(4)_L x U(1)_X symmetry where the scalar spectrum needed to generate gauge boson and fermion masses has a smaller scalar content than usually assumed in literature. We compute the running of its abelian gauge coupling and show that a Landau pole shows up at the TeV scale, a fact that we use to consistently impl

  9. Begoña Ascaso, Brian C. Lemaux, Lori M. Lubin, Roy R. Gal

    In this study we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift ($z\sim0.9$), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift ($z\sim0.1$) counterparts drawn from the MCXC meta-catalog, supplemented by SDSS

  10. Samuel Monnier

    We prove a formula for the global gravitational anomaly of the self-dual field theory in the presence of background gauge fields, assuming the results of arXiv:1110.4639. Along the way, we also clarify various points about the self-dual field theory. In particular, we give a general definition of the theta characteristic entering its partition function and s

  11. Mark C. Neyrinck, Miguel A. Aragon-Calvo, Donghui Jeong, Xin Wang

    We study the relationship between dark-matter haloes and matter in the MIP $N$-body simulation ensemble, which allows precision measurements of this relationship, even deeply into voids. What enables this is a lack of discreteness, stochasticity, and exclusion, achieved by averaging over hundreds of possible sets of initial small-scale modes, while holding f

  12. Hooman Davoudiasl, Ian M. Lewis

    We examine the possibility that dark matter may be the manifestation of dark forces of a hidden sector, i.e. "Dark Force = Dark Matter." As an illustrative and minimal example we consider the hidden SU(2)_h x U(1)_h gauge group. The hidden dynamics is indirectly coupled to the Standard Model (SM) through kinetic mixing of U(1)_h with the U(1)_Y of hy

  13. Lauren E. Hayward, David G. Hawthorn, Roger G. Melko, Subir Sachdev

    The hole-doped cuprate high temperature superconductors enter the pseudogap regime as their superconducting critical temperature, $T_c$, falls with decreasing hole density. Experiments have probed this regime for over two decades, but we argue that decisive new information has emerged from recent X-ray scattering experiments (arXiv:1207.0915, arXiv:1206.4333

  14. Joseph A. Muñoz, Steven R. Furlanetto

    We test the ability of equilibrium galactic disk and one-zone interstellar medium models to describe the physical and emission properties of quasar hosts, submillimeter galaxies, and Lyman-alpha emitters at z>~6. The size, line widths, star formation rates, black hole accretion rates, gas masses and temperatures, and the relationships between these propertie

  15. Carsten Weidner, Pavel Kroupa, Jan Pflamm-Altenburg, Alexandre Vazdekis

    Observational studies are showing that the galaxy-wide stellar initial mass function are top-heavy in galaxies with high star-formation rates (SFRs). Calculating the integrated galactic stellar initial mass function (IGIMF) as a function of the SFR of a galaxy, it follows that galaxies which have or which formed with SFRs > 10 Msol yr^-1 would have a top-hea

  16. Jinrui Huang, Tao Liu, Lian-Tao Wang, Felix Yu

    We reveal a set of novel decay topologies for the 125 GeV Higgs boson in supersymmetry which are initiated by its decay into a pair of neutralinos, and discuss their collider search strategies. This category of exotic Higgs decays are characterized by the collider signature: visible objects + $\mbox{${\not\! E}_{\rm T}$}$, with $\mbox{${\not\! E}_{\rm T}$}$

  17. Emidio Gabrielli, Matti Heikinheimo, Kristjan Kannike, Antonio Racioppi

    We study the standard model (SM) in its full perturbative validity range between $Λ_QCD$ and the $U(1)_Y$ Landau pole, assuming that a yet unknown gravitational theory in the UV does not introduce additional particle thresholds, as suggested by the tiny cosmological constant and the absence of new stabilising physics at the EW scale. We find that, due to dim

  18. Zhen Lei, Esteban A. Navas, Qi S. Zhang

    Let $v$ be the velocity of Leray-Hopf solutions to the axially symmetric three-dimensional Navier-Stokes equations. Under suitable conditions for initial values, we prove the following a priori bound \[ |v(x, t)| \le \frac{C}{r^2} |\ln r|^{1/2}, \]where $r \in (0, 1/2)$ is the distance from $x$ to the z axis, and $C$ is a constant depending only on the initi

  19. Bethany Marsh, Jeanne Scott

    The homogeneous coordinate ring of the Grassmannian Gr(k,n) has a cluster structure defined in terms of planar diagrams known as Postnikov diagrams. The cluster corresponding to such a diagram consists entirely of Pluecker coordinates. We introduce a twist map on Gr(k,n), related to the Berenstein-Fomin-Zelevinsky-twist, and give an explicit Laurent expansio

  20. Xin Wang, Gong-Bo Zhao

    We develop an accurate and efficient Bayesian method to reconstruct the primordial power spectrum in a model-independent way, and apply it to the latest cosmic microwave background measurement from Planck mission, and the large scale structure observation of SDSS-III BOSS (CMASS) sample, combined with the type Ia supernovae sample (SNLS 3-year) and the measu

  21. S. M. M. Rasouli, A. H. Ziaie, J. Marto, P. V. Moniz

    We study the gravitational collapse of a homogeneous scalar field, minimally coupled to gravity, in the presence of a particular type of dynamical deformation between the canonical momenta of the scale factor and of the scalar field. In the absence of such a deformation, a class of solutions can be found in the literature [R. Goswami and P. S. Joshi, arXiv:g

  22. Joshua Combes, Christopher Ferrie, Zhang Jiang, Carlton M. Caves

    Probabilistic metrology attempts to improve parameter estimation by occasionally reporting an excellent estimate and the rest of the time either guessing or doing nothing at all. Here we show that probabilistic metrology can never improve quantum limits on estimation of a single parameter, both on average and asymptotically in number of trials, if performanc

  23. Liane Gabora

    This paper describes a tentative model for how discrete memories transform into an interconnected conceptual network, or worldview, wherein relationships between memories are forged by way of abstractions. The model draws on Kauffman's theory of how an information-evolving system could emerge through the formation and closure of an autocatalytic network.

  24. Solomon Akaraka Owerre, M. B. Paranjape

    We show how to calculate the amplitude for quantum spin tunneling with a $z$ easy axis. In this case, using the usual spherical polar angles to parametrize spin coherent states, typically the tunnelling variable is the polar angle $θ$, passing from 0 to $π$, while the azimuthal angle $ϕ$ is imaginary and constant. As the energy is constant along the tunnelli

  25. Nami Mowlavi, Sophie Saesen, Fabio Barblan, Laurent Eyer

    We summarize the properties of the new periodic, small amplitude, variable stars recently discovered in the open cluster NGC 3766. They are located in the region of the Hertzsprung-Russell diagram between δ Sct and slowly pulsating B stars, a region where no sustained pulsation is predicted by standard models. The origin of their periodic variability is curr

  26. Skip Garibaldi, Robert Guralnick

    We study the problem of determining, for a polynomial function $f$ on a vector space $V$, the linear transformations $g$ of $V$ such that $f g = f$. In case $f$ is invariant under a simple algebraic group $G$ acting irreducibly on $V$, we note that the subgroup of $GL(V)$ stabilizing $f$ often has identity component $G$ and we give applications realizing var

  27. Lakshmi Anantharamu, Bogdan S. Chlebus, Mariusz A. Rokicki

    We study deterministic distributed broadcasting in synchronous multiple-access channels. Packets are injected into $n$ nodes by a window-type adversary that is constrained by a window $w$ and injection rates individually assigned to all nodes. We investigate what queue size and packet latency can be achieved with the maximum aggregate injection rate of one p

  28. H Weigel

    For kink-antikink scattering within the ϕ^4 non--linear field theory in one space and one time dimension resonance type configurations emerge when the relative velocity between kink and antikink falls below a critical value. It has been conjectured that the vibrational excitation of the kink would be the source for these resonances because (simplified) colle

  29. Daniel Fox, Joe S. Wang

    The exterior differential system for constant mean curvature (CMC) surfaces in a 3-dimensional space form is an elliptic Monge-Ampere system defined on the unit tangent bundle. We determine the infinite sequence of higher-order symmetries and conservation laws via an enhanced prolongation modelled on a loop algebra valued formal Killing field. As a consequen

  30. Quentin Bramas, Sébastien Tixeuil

    We consider the problem of scattering $n$ robots in a two dimensional continuous space. As this problem is impossible to solve in a deterministic manner, all solutions must be probabilistic. We investigate the amount of randomness (that is, the number of random bits used by the robots) that is required to achieve scattering. We first prove that $n \log n$ ra

  31. Daniel de Florian, Javier Mazzitelli

    We compute the next-to-next-to-leading order QCD corrections for Standard Model Higgs boson pair production inclusive cross section at hadron colliders within the large top-mass approximation. We provide numerical results for the LHC, finding that the corrections are large, resulting in an increase of ${\cal O}(20%)$ with respect to the next-to-leading order

  32. José Luis Jaramillo

    Black hole horizon sections, modelled as marginally outer trapped surfaces (MOTS), possess a notion of stability admitting a spectral characterization. Specifically, the "principal eigenvalue" λ_o of the MOTS-stability operator (an elliptic operator on horizon sections) must be non-negative. We discuss the expression of λ_o for axisymmetric stationar

  33. Giacomo Micheli, Davide Schipani

    Explicit monoid structure is provided for the class of canonical subfield preserving polynomials over finite fields. Some classical results and asymptotic estimates will follow as corollaries.

  34. Galina Weinstein

    In 1917 Einstein introduced into his field equations a cosmological term having the cosmological constant as a coefficient, in order that the theory should yield a static universe. Einstein desired to eliminate absolute space from physics according to "Mach's ideas". De Sitter objected to the "world-matter" in Einstein's world, and pr

  35. Liane Gabora

    What can relics of the past tell us about the thoughts and beliefs of the people who invented and used them? Recent collaborations at the frontier of archaeology, anthropology, and cognitive science are culminating in speculative but nevertheless increasingly sophisticated efforts to unravel how modern human cognition came about. By considering objects withi

  36. Neven Bilic, Gary B. Tupper

    We review the tachyon model derived from the dynamics of a 3-brane moving in the AdS5 bulk. The bulk geometry is based on the Randall-Sundrum II model extended to include the radion. The effective tachyon Lagrangian is modified due to the back-reaction of the brane on the bulk geometry.

  37. Gilad Gour, Markus P. Müller, Varun Narasimhachar, Robert W. Spekkens

    We review recent work on the foundations of thermodynamics in the light of quantum information theory. We adopt a resource-theoretic perspective, wherein thermodynamics is formulated as a theory of what agents can achieve under a particular restriction, namely, that the only state preparations and transformations that they can implement for free are those th

  38. Liane Gabora

    This paper presents Wanderer, a model of how autonomous adaptive systems coordinate internal biological needs with moment-by-moment assessments of the probabilities of events in the external world. The extent to which Wanderer moves about or explores its environment reflects the relative activations of two competing motivational sub-systems: one represents t

  39. Alastair King, Matthew Pressland

    We study the set S of labelled seeds of a cluster algebra of rank n inside a field F as a homogeneous space for the group M_n of (globally defined) mutations and relabellings. Regular equivalence relations on S are associated to subgroups W of Aut_{M_n}(S), and we thus obtain groupoids W \ S. We show that for two natural choices of equivalence relation, the

  40. David A. Lowe, Ilies Messamah, Antun Skanata

    Massless fields propagating in a generic Kerr black hole background enjoy a hidden SL(2,R)xSL(2,R) symmetry. We determine how the exact mode functions decompose into representations of this symmetry group. This extends earlier results on the low frequency limit of the massless scalar case to finite frequencies and general spin. As an application, we numerica

  41. Marcus Barth, Johannes Hofmann

    The spectral function of a spin-balanced two-dimensional Fermi gas with short-range interactions is calculated by means of a quantum cluster expansion. Good qualitative agreement is found with a recent experiment by Feld $\textit{et al.}$ [Nature (London) $\textbf{480}$, 75 (2011)]. The effects of pairing are clearly visible in the density of states, which d

  42. Y. Kiyo, Y. Sumino

    We compute the energy levels of some of the lower-lying heavy quarkonium states perturbatively up to O(alpha_s^5*m) and O(alpha_s^5*m*log[alpha_s]). Stability of the predictions depends crucially on the unknown 4-loop pole-MSbar mass relation. We discuss the current status of the predictions with respect to the observed bottomonium spectrum.

  43. Benjamin Bakker, Jacob Tsimerman

    The Frey--Mazur conjecture states that an elliptic curve over $\mathbb{Q}$ is determined up to isogeny by its $p$-torsion Galois representation for $p\geq 17$. We study a geometric analog of this conjecture, and show that the map from isogeny classes of "fake elliptic curves"---abelian surfaces with quaternionic multiplication---to their $p$-torsion

  44. A. E. Cárcamo Hernández, R Martínez, F. Ochoa

    We propose a 3-3-1 model where the $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ symmetry is extended by $S_{3}\otimes Z_{3}\otimes Z_{3}^{\prime }\otimes Z_{8}\otimes Z_{16}$ and the scalar spectrum is enlarged by extra $% SU(3)_{L}$ singlet scalar fields. The model successfully describes the observed SM fermion mass and mixing pattern. In this framework, th

  45. Mario Einax

    The development of efficient artificial nanodevices poses challenges which are of fundamental and technological nature. Recent progress has been made in the context of finite-time thermodynamics. A central question in finite-time thermodynamics is to identify the optimal procedure to extract the greatest amount of work from a system operating under well-defi

  46. Nemanja Kaloper, Antonio Padilla

    We propose a very simple reformulation of General Relativity, which completely sequesters from gravity {\it all} of the vacuum energy from a matter sector, including all loop corrections and renders all contributions from phase transitions automatically small. The idea is to make the dimensional parameters in the matter sector functionals of the 4-volume ele

  47. Christoph Spengler, Barbara Kraus

    A pair of orthonormal bases is called mutually unbiased if all mutual overlaps between any element of one basis with an arbitrary element of the other basis coincide. In case the dimension, $d$, of the considered Hilbert space is a power of a prime number, complete sets of $d+1$ mutually unbiased bases (MUBs) exist. Here, we present a novel method based on t

  48. Chiaki Yamaguchi

    We analytically estimate the locations of phase transition points in the ground state for the $\pm J$ random bond Ising model with asymmetric bond distributions on the square lattice. We propose and study the percolation transitions for two types of bond shared by two non-frustrated plaquettes. The present method indirectly treats the sizes of clusters of co

  49. Necdet Serhat Aybat, Garud Iyengar

    The stable principal component pursuit (SPCP) is a non-smooth convex optimization problem, the solution of which enables one to reliably recover the low rank and sparse components of a data matrix which is corrupted by a dense noise matrix, even when only a fraction of data entries are observable. In this paper, we propose a new algorithm for solving SPCP. T

  50. Elodie Gazave, Li Ma, Diana Chang, Alex Coventry

    Human populations have experienced dramatic growth since the Neolithic revolution. Recent studies that sequenced a very large number of individuals observed an extreme excess of rare variants, and provided clear evidence of recent rapid growth in effective population size, though estimates have varied greatly among studies. All these studies were based on pr

  51. Ryuhei Mori

    The Bethe approximation is a well-known approximation of the partition function used in statistical physics. Recently, an equality relating the partition function and its Bethe approximation was obtained for graphical models with binary variables by Chertkov and Chernyak. In this equality, the multiplicative error in the Bethe approximation is represented as

  52. Shamik Ghosh

    There have been recent reports of unexpectedly large velocity dipole in the NRAO VLA Sky Survey data. We investigate whether the excess in the NVSS dipole reported can be of cosmological origin. We assume a long wavelength inhomogeneous scalar perturbation of the form αsin (κz) and study its effects on the matter density contrasts. Assuming an ideal fluid mo

  53. N. A. Schwadron, D. J. McComas

    Plasma wave observations from Voyager 1 have recently shown large increases in plasma density, to about 0.1 cm^{-3}, consistent with the density of the local interstellar medium. However, corresponding magnetic field observations continue to show the spiral magnetic field direction observed throughout the inner heliosheath. These apparently contradictory obs

  54. Andrea Negri, Luca Ciotti, Silvia Pellegrini

    Observational and numerical studies gave hints that the hot gaseous haloes of ETGs may be sensitive to the galaxy internal kinematics. By using high resolution 2D hydro simulations, and realistic two-component (stars plus dark matter) axisymmetric galaxy models, we study the evolution of the hot haloes in a suite of flat ETGs of fixed mass distribution, but

  55. Farzad Ghafari Jouneghani, Mohammad Babazadeh, Rogayeh Bayramzadeh, Hossein Movla

    Graphical Models have various applications in science and engineering which include physics, bioinformatics, telecommunication and etc. Usage of graphical models needs complex computations in order to evaluation of marginal functions,so there are some powerful methods including mean field approximation, belief propagation algorithm and etc. Quantum graphical

  56. V. C. Busti, R. F. L. Holanda, C. Clarkson

    Correctly interpreting observations of sources such as type Ia supernovae (SNe Ia) require knowledge of the power spectrum of matter on AU scales - which is very hard to model accurately. Because under-dense regions account for much of the volume of the universe, light from a typical source probes a mean density significantly below the cosmic mean. The relat

  57. Weisheng Wu

    Let $M$ be a smooth compact surface of nonpositive curvature, with genus $\geq 2$. We prove the ergodicity of the geodesic flow on the unit tangent bundle of $M$ with respect to the Liouville measure under the condition that the set of points with negative curvature on $M$ has finitely many connected components. Under the same condition, we prove that a non

  58. Sabyasachi Chakraborty, Sourov Roy

    We discuss neutrino masses and mixing in the framework of a supersymmetric model with an $U(1)_{R}$ symmetry, consisting of a single right handed neutrino superfield with an appropriate R charge. The lepton number ($L$) of the standard model fermions are identified with the negative of their R-charges. As a result, a subset of leptonic R-parity violating ope

  59. LHCb collaboration, R. Aaij, B. Adeva, M. Adinolfi

    Measurements of charm mixing parameters from the decay-time-dependent ratio of D0->K+pi- to D0->K-pi+ rates and the charge-conjugate ratio are reported. The analysis uses data, corresponding to 3 fb^{-1} of integrated luminosity, from proton-proton collisions at 7 and 8 TeV center-of-mass energies recorded by the LHCb experiment. In the limit of charge-parit

  60. Daniel Huybrechts

    In this note we interpret a recent result of Gaberdiel, Hohenegger and Volpato in terms of derived equivalences of K3 surfaces. We prove that there is a natural bijection between subgroups of the Conway group Co_1 with invariant lattice of rank at least four and groups of symplectic derived equivalences of D(Coh(X)) of projective K3 surfaces fixing a stabili

  61. Karin Baur, Alastair King, Bethany Marsh

    We associate a dimer algebra A to a Postnikov diagram D (in a disk) corresponding to a cluster of minors in the cluster structure of the Grassmannian Gr(k,n). We show that A is isomorphic to the endomorphism algebra of a corresponding Cohen-Macaulay module T over the algebra B used to categorify the cluster structure of Gr(k,n) by Jensen-King-Su. It follows

  62. Simon Caron-Huot

    We propose the eikonal approximation as a simple and reliable tool to analyze relativistic high-energy processes, provided that the necessary subtleties are accounted for. An important subtlety is the need to include eikonal phases for a rapidity-dependent collection of particles, as embodied by the Balitsky-JIMWLK rapidity evolution equation. In the first p

  63. Berislav Buca, Tomaz Prosen

    We study the full counting statistics for interacting quantum many-body spin systems weakly coupled to the environment. In the leading order in the system-bath coupling we derive exact spin current statistics for a large class of parity symmetric spin-1/2 systems driven by a pair of Markovian baths with local coupling operators. Interestingly, in this class

  64. Farid Shahandeh, Jan Sperling, Werner Vogel

    The general class of Gaussian Schmidt-number witness operators for bipartite systems is studied. It is shown that any member of this class is reducible to a convex combination of two types of Gaussian operators using local operations and classical communications. This gives rise to a simple operational method, which is solely based on measurable covariance m

  65. K. Trachenko, V. V. Brazhkin, D. Bolmatov

    Understanding physics of gas giants requires the knowledge about the behavior of hydrogen at extreme pressures and temperatures. Molecular hydrogen in these planets is supercritical, and has been considered as a physically homogeneous state where no differences can be made between a liquid and a gas and where all properties undergo no marked or distinct chan

  66. V. V. Brazhkin, K. Trachenko

    Disorder has been long considered as a formidable foe of theoretical physicists in their attempts to understand system's behavior. Here, we review recently accumulated data and propose that from the point of view of calculating thermodynamic properties, the problem of disorder may not be as severe as has been hitherto assumed. We particularly emphasize t

  67. P. Crivelli, D. Cooke, B. Barbiellini, B. L. Brown

    Recently, evidence for positronium (Ps) in a Bloch state in self-assembled metal--organic frameworks (MOFs) has been reported [Dutta et al., Phys. Rev. Lett. 110, 197403 (2013)]. In this paper, we study Ps emission into vacuum from four different MOFs crystals: MOF-5, IRMOF-8, FMA and IRMOF-20. Our measurements of Ps yield and emission energy into vacuum pro

  68. A. Thilagam

    We evaluate the binding energies of systems of bosonic and fermionic particles on the basis of the quantum Szilard engine, which confers an energetic value to information and entropy changes. We extend treatment of the quantum information thermodynamic operation of the Szilard engine to its non-trivial role in Bose-Einstein condensation of the light mass pol

  69. A. A. Banishev, G. L. Klimchitskaya, V. M. Mostepanenko, U. Mohideen

    We present the complete results for the dynamic experiment on measuring the gradient of the Casimir force between magnetic (Ni-coated) surfaces of a plate and a sphere. Special attention is paid to the description of some details of the setup, its calibration, error analysis and background effects. Computations are performed in the framework of the Lifshitz

  70. R. L. Doretto

    We study the plaquette valence-bond solid phase of the spin-1/2 J_1-J_2 antiferromagnet Heisenberg model on the square lattice within the bond-operator theory. We start by considering four S = 1/2 spins on a single plaquette and determine the bond operator representation for the spin operators in terms of singlet, triplet, and quintet boson operators. The fo

  71. Xi Peng, Huajin Tang, Lei Zhang, Zhang Yi

    Under the framework of spectral clustering, the key of subspace clustering is building a similarity graph which describes the neighborhood relations among data points. Some recent works build the graph using sparse, low-rank, and $\ell_2$-norm-based representation, and have achieved state-of-the-art performance. However, these methods have suffered from the

  72. Jack Dobinson, Zoë M. Leinhardt, Sarah E. Dodson-Robinson, Nick A. Teanby

    Transitional and pre--transitional disks can be explained by a number of mechanisms. This work aims to find a single observationally detectable marker that would imply a planetary origin for the gap and, therefore, indirectly indicate the presence of a young planet. N-body simulations were conducted to investigate the effect of an embedded planet of one Jupi

  73. Luu Hoang Duc, Björn Schmalfuss, Stefan Siegmund

    In this note we prove that a fractional stochastic delay differential equation which satisfies natural regularity conditions generates a continuous random dynamical system on a subspace of a Hölder space which is separable.

  74. Marie G. Christ, Lene M. Favrholdt, Kim S. Larsen

    Bin covering is a dual version of classic bin packing. Thus, the goal is to cover as many bins as possible, where covering a bin means packing items of total size at least one in the bin. For online bin covering, competitive analysis fails to distinguish between most algorithms of interest; all "reasonable" algorithms have a competitive ratio of 1/2.

  75. Josep Diaz, Ioannis Giotis, Lefteris Kirousis, Evangelos Markakis

    The Generalized Second Price (GSP) auction used typically to model sponsored search auctions does not include the notion of budget constraints, which is present in practice. Motivated by this, we introduce the different variants of GSP auctions that take budgets into account in natural ways. We examine their stability by focusing on the existence of Nash equ

  76. Pierre E. Jacob, Alexandre H. Thiery

    We study the existence of algorithms generating almost surely nonnegative unbiased estimators. We show that given a nonconstant real-valued function $f$ and a sequence of unbiased estimators of $λ\in\mathbb{R}$, there is no algorithm yielding almost surely nonnegative unbiased estimators of $f(λ)\in\mathbb{R}^+$. The study is motivated by pseudo-marginal Mon

  77. Elefterios Soultanis

    We study notions of homotopy in the Newtonian space $N^{1,p}(X;Y)$ of Sobolev type maps between metric spaces. After studying the properties and relations of two different notions we prove a compactness result for sequences in homotopy classes with controlled homotopies.

  78. Arman Boyacı, Tınaz Ekim, Mordechai Shalom, Shmuel Zaks

    Given a tree and a set P of non-trivial simple paths on it, VPT(P) is the VPT graph (i.e. the vertex intersection graph) of the paths P, and EPT(P) is the EPT graph (i.e. the edge intersection graph) of P. These graphs have been extensively studied in the literature. Given two (edge) intersecting paths in a graph, their split vertices is the set of vertices

  79. Matthew Tointon

    A bracket polynomial on the integers is a function formed using the operations of addition, multiplication and taking fractional parts. For a fairly large class of bracket polynomials we show that if p is a bracket polynomial of degree k-1 on [N] then the function f defined by f(n) = e(p(n)) has Gowers U^k[N]-norm bounded away from zero, uniformly in N. We e

  80. Matthew Fayers

    Suppose $λ$ and $μ$ are integer partitions with $λ\supseteqμ$. Kenyon and Wilson have introduced the notion of a cover-inclusive Dyck tiling of the skew Young diagram $λ\setminusμ$, which has applications in the study of double-dimer models. We examine these tilings in more detail, giving various equivalent conditions and then proving a recurrence which we u

  81. Maxim Nazarov, Evgeny Sklyanin

    A hierarchy of pairwise commuting Hamiltonians for the quantum periodic Benjamin-Ono equation is constructed by using the Lax matrix. The eigenvectors of these Hamiltonians are Jack symmetric functions of infinitely many variables $x_1,x_2,\ldots$. This construction provides explicit expressions for the Hamiltonians in terms of the power sum symmetric functi

  82. Keisuke Izumi, Je-An Gu, Yen Chin Ong

    We show the existence of physical superluminal modes and acausality in the Brans-Dicke type of extension of teleparallel gravity that includes F(T) gravity and teleparallel dark energy as special cases. We derive the characteristic hypersurface for the extra degrees of freedom in the theory, thereby showing that the time evolution is not unique and closed ca

  83. Sudhaker Upadhyay

    We analyse the constraints of an Abelian 2-form gauge theory using Faddeev-Jackiw symplectic formalism. Further, this theory is treated as a constrained system in the context of Batalin-Fradkin-Vilkovisky formalism to retrieve the BRST symmetry. Using the fields decompositions the effective action for Abelian 2-form gauge theory is written in terms of diagon

  84. Karol Szałowski

    The indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling between on-site magnetic impurities is studied for two kinds of graphene nanoflakes consisting of approximately 100 carbon atoms, posessing either zigzag or armchair edge. The tight-binding Hamiltonian with Hubbard term is used in non-perturbative calculations of coupling between the impurities place

  85. Pawel Gawrychowski, Przemyslaw Uznanski

    We study a generalization of the recently introduced order-preserving pattern matching, where instead of looking for an exact copy of the pattern, we only require that the relative order between the elements is the same. In our variant, we additionally allow up to k mismatches between the pattern and the text, and the goal is to construct an efficient algori

  86. Michael Luckeneder, Adam Barker

    When orchestrating highly distributed and data-intensive Web service workflows the geographical placement of the orchestration engine can greatly affect the overall performance of a workflow. Orchestration engines are typically run from within an organisations' network, and may have to transfer data across long geographical distances, which in turn incre

  87. Po-Hao Chang, Farzad Mahfouzi, Naoto Nagaosa, Branislav K. Nikolic

    We study the transverse spin-Seebeck effect (SSE) on the surface of a three-dimensional topological insulator (TI) thin film, such as Bi$_2$Se$_3$, which is sandwiched between two normal metal leads. The temperature bias $ΔT$ applied between the leads generates surface charge current which becomes spin-polarized due to strong spin-orbit coupling on the TI su

  88. A. C. H. Rowe

    Piezoresistance is the change in the electrical resistance, or more specifically the resistivity, of a solid induced by an applied mechanical stress. The origin of this effect in bulk, crystalline materials like Silicon, is principally a change in the electronic structure which leads to a modification of the charge carriers effective mass. The last few years

  89. F. Roma, D. Dominguez

    The critical behavior of the gauge-glass and the XY spin-glass models in three dimensions is studied by analyzing their nonequilibrium aging dynamics. A new numerical method, which relies on the calculation of the two-time correlation and integrated response functions, is used to determine both the critical temperature and the nonequilibrium scaling exponent

  90. Roland Cristopher F. Caballar, Sebastian Diehl, Harri Mäkelä, Markus Oberthaler

    We develop a dissipative quantum state preparation scheme for the creation of phase- and number-squeezed states. It utilizes ultracold atoms in a double-well configuration immersed in a background Bose-Einstein condensate, with the latter consisting of an atom species different from the atoms in the double well and acting as a dissipative quantum reservoir.

  91. Bernd Fröhlich, James F. Dynes, Marco Lucamarini, Andrew W. Sharpe

    The theoretically proven security of quantum key distribution (QKD) could revolutionise how information exchange is protected in the future. Several field tests of QKD have proven it to be a reliable technology for cryptographic key exchange and have demonstrated nodal networks of point-to-point links. However, so far no convincing answer has been given to t

  92. Ofer Gabber, Philippe Gille, Laurent Moret-Bailly

    Let (K,v) be a valued field, Y a K-variety, G an algebraic group over K (not necessarily smooth), and f: X->Y a G-torsor over Y. We consider the induced map X(K)-->Y(K), which is continuous for the topologies deduced from the valuation. Let I denote the image of this map. We prove that if (K,v) is henselian and its completion is a separable extension, then:

  93. Ewa Schmeidel Robert Jankowski

    Using the Riccati transformation techniques, we will extend some almost oscillation criteria for the second-order nonlinear neutral difference equation with quasidifferences $$Δ\left(r_n\left(Δ\left(x_n+c x_{n-k}\right)\right)^γ\right)+q_nx_{n+1}^α=e_n.$$

  94. Dusa McDuff, Emmanuel Opshtein

    This paper investigates the geometry of a symplectic 4-manifold $(M,\om)$ relative to a J-holomorphic normal crossing divisor S. Extending work by Biran (in Invent. Math. 1999), we give conditions under which a homology class $A\in H_2(M;\Z)$ with nontrivial Gromov invariant has an embedded J-holomorphic representative for some S-compatible J. This holds for

  95. G. Waldherr, Y. Wang, S. Zaiser, M. Jamali

    Hybrid quantum systems seek to combine the strength of its constituents to master the fundamental conflicting requirements of quantum technology: fast and accurate systems control together with perfect shielding from the environment, including the measurements apparatus, to achieve long quantum coherence. Excellent examples for hybrid quantum systems are het

  96. Jean-Marc Gambaudo, Patrizia Vignolo

    We propose a scheme to determine the energy-band dispersion of quasicrystals which does not require any periodic approximation and which directly provides the correct structure of the extended Brillouin zones. In the gap labelling viewpoint, this allow to transpose the measure of the integrated density-of-states to the measure of the effective Brillouin-zone

  97. Omid Kavehei, Efstratios Skafidas

    Thermodynamic-driven filament formation in redox-based resistive memory and the impact of thermal fluctuations on switching probability of emerging magnetic switches are probabilistic phenomena in nature, and thus, processes of binary switching in these nonvolatile memories are stochastic and vary from switching cycle-to-switching cycle, in the same device,

  98. Gabriele Campagnano, Oded Zilberberg, Igor V. Gornyi, Yuval Gefen

    We study a Hanbury Brown and Twiss (HBT) interferometer formed with chiral edge channels of a quantum Hall system. HBT cross-correlations are calculated for a device operating both in the integer and fractional quantum Hall regimes, the latter at Laughlin filling fractions. We find that in both cases, when the current is dominated by electron tunneling, curr

  99. Henrik Nyman, Johan Pensar, Timo Koski, Jukka Corander

    Theory of graphical models has matured over more than three decades to provide the backbone for several classes of models that are used in a myriad of applications such as genetic mapping of diseases, credit risk evaluation, reliability and computer security, etc. Despite of their generic applicability and wide adoptance, the constraints imposed by undirecte

  100. K. Bamba, Md. Wali Hossain, R. Myrzakulov, S. Nojiri

    In this paper we investigate the case of non-minimal coupling in the (extended) nonlinear massive gravity theories. We first consider massive gravity in the Brans-Dicke background such that the graviton mass is replaced by $A^2(σ)m$ where $σ$ is the Brans-Dicke field and $A(σ)$ is conformal coupling and show that there is no viable thermal history of the uni