October 2010 arXiv papers — page 17

Deniz Karli

In this paper, we consider a product of a symmetric stable process in $\mathbb{R}^d$ and a one-dimensional Brownian motion in $\mathbb{R}^+$. Then we define a class of harmonic functions with respect to this product process. We show that bounded non-negative harmonic functions in the upper-half space satisfy Harnack inequality and prove that they are locally

Aleksey Kostenko, Alexander Sakhnovich, Gerald Teschl

We explore the connections between singular Weyl-Titchmarsh theory and the single and double commutation methods. In particular, we compute the singular Weyl function of the commuted operators in terms of the original operator. We apply the results to spherical Schroedinger operators (also known as Bessel operators). We also investigate the connections with

Agissilaos Athanassoulis, Thierry Paul, Federica Pezzotti, Mario Pulvirenti

In this paper we consider the nonlinear Hartree equation in presence of a given external potential, for an initial coherent state. Under suitable smoothness assumptions, we approximate the solution in terms of a time dependent coherent state, whose phase and amplitude can be determined by a classical flow. The error can be estimated in $L^2$ by $C \sqrt {\va

Aleksandar Mikovic, Marko Vojinovic

We study the problem of semiclassical limit of Loop Quantum Gravity theory defined by the new spin foam models. This is done by analyzing the large-spin asymptotics of the Hartle-Hawking wavefunction. By using the stationary phase method we determine the wavefunction asymptotics, which then determines the large-distance asymptotics of the corresponding gravi

Chris K. Caldwell, Yuanyou Furui Cheng

In 1947 Mills proved that there exists a constant $A$ such that $\lfloor A^{3^n} \rfloor$ is a prime for every positive integer $n$. Determining $A$ requires determining an effective Hoheisel type result on the primes in short intervals - though most books ignore this difficulty. Under the Riemann Hypothesis, we show that there exists at least one prime betw

Marios Karouzos, Silke Britzen, Arno Witzel, Anton Zensus

The recent release of the First Fermi-LAT Source Catalog solidified the predominant association of extragalactic gamma-ray emitters to active galaxies, in particular blazars. A tight connection between AGN jet kinematics and gamma-ray properties has been argued for, attributing the energetic emission from active galaxies to their highly relativistic outflows

Claudio Giberti, Lamberto Rondoni

One dimensional systems are under intense investigation, both from theoretical and experimental points of view, since they have rather peculiar characteristics which are of both conceptual and technological interest. We analyze the dependence of the behaviour of one dimensional, time reversal invariant, nonequilibrium systems on the parameters defining their

R. R. Akhmetshin, V. M. Aulchenko, V. Sh. Banzarov, L. M. Barkov

The $ϕ$(1020) meson leptonic width has been determined from the combined analysis of 4 major decay modes of the resonance ($ϕ\to K^+ K^-,K^0_LK^0_S,π^+π^-π^0,ηγ$) studied with the CMD-2 detector at the VEPP-2M $e^+e^-$ collider. The following value has been obtained: $Γ(ϕ\to e^+e^-) = 1.235\pm 0.006\pm 0.022$ keV. The $ϕ(1020)$ meson parameters in four main

David Ellis, Benny Sudakov

If X is an n-element set, we call a family G of subsets of X a k-generator for X if every subset of X can be expressed as a union of at most k disjoint sets in G. Frein, Leveque and Sebo conjectured that for n > 2k, the smallest k-generators for X are obtained by taking a partition of X into classes of sizes as equal as possible, and taking the union of the

Mehmet Akif Antepli, Elif Uysal-Biyikoglu, Hakan Erkal

The minimization of transmission completion time for a given number of bits per user in an energy harvesting communication system, where energy harvesting instants are known in an offline manner is considered. An achievable rate region with structural properties satisfied by the 2-user AWGN Broadcast Channel capacity region is assumed. It is shown that even

Salman Khan, M. Ramzan, M. K. Khan

We reformulate the quantum Monty Hall problem in the presence of decoherence. The decoherence destroys the fairness of the game. A new Nash equilibrium for a particular strategy profile in the presence of decoherence emerges. It is shown that in the presence of decoherence under the action of amplitude damping channel, Bob's winning probability is always

M. Jablan, M. Soljačić, H. Buljan

We calculate hybridization of plasmons and intrinsic optical phonons in graphene by using the self-consistent linear response formalism. We find that longitudinal plasmons (transverse magnetic modes) couple exclusively to transverse optical phonons, whereas graphene's transverse plasmons (transverse electric modes) couple only to longitudinal optical pho

Grégory Maillard, Thomas Mountford, Samuel Schöpfer

We consider the parabolic Anderson model $\partial u/\partial t = κΔu + γξu$ with $u\colon\, \Z^d\times R^+\to \R^+$, where $κ\in\R^+$ is the diffusion constant, $Δ$ is the discrete Laplacian, $γ\in\R^+$ is the coupling constant, and $ξ\colon\,\Z^d\times \R^+\to\{0,1\}$ is the voter model starting from Bernoulli product measure $ν_ρ$ with density $ρ\in (0,1)

Fabienne Castell, Onur Gün, Grégory Maillard

We consider the parabolic Anderson model (PAM) which is given by the equation $\partial u/\partial t = κΔu + ξu$ with $u\colon\, \Z^d\times [0,\infty)\to \R$, where $κ\in [0,\infty)$ is the diffusion constant, $Δ$ is the discrete Laplacian, and $ξ\colon\,\Z^d\times [0,\infty)\to\R$ is a space-time random environment that drives the equation. The solution of

Hubert Lacoin, Remi Leblond

We study the time that the simple exclusion process on the complete graph needs to reach equilibrium in terms of total variation distance. For the graph with n vertices and 1<<k<n/2 particles we show that the mixing time is of order (n/2)\log \min(k, \sqrt{n}), and that around this time, for any small positive epsilon the total variation distance drops from

Dan Lascu

We study a family of continued fraction expansion of reals from the unit interval. The Perron-Frobenius operator of the transformation which generates this expansion under the invariant measure of this transformation is given. Using the ergodic behavior of homogeneous random system with complete connections associated with this expansion we solve a variant o

Dan Lascu, Katsunori Kawamura

We introduced a new continued fraction expansions in our previous paper. For these expansions, we show formulae of probability about incomplete quotients. Furthermore, we prove the existence of invariant measures with respect to the continued fraction transformations associated with expansions.

Matthias Meng

We describe an explicit crystal morphism between Nakajima monomials and monomials which give a realization of crystal bases for finite dimensional irreducible modules over the quantized enveloping algebra for Lie algebras of type A and C. This morphism provides a connection between arbitrary Nakajima monomials and Nakashima Kashiwara tableaux. This yields a

T. Stauber

We present analytical expressions for the polarizability $P_μ(q_x,ω)$ of graphene modeled by the hexagonal tight-binding model for small wave number $q_x$, but arbitrary chemical potential $μ$. Generally, we find $P_μ(q_x,ω)=P_μ^<(ω/ω_q)+q_x^2P_μ^>(ω)$ with $ω_q=v_Fq_x$ the Dirac energy, where the first term is due to intra-band and the second due to inter-b

Simon Schettler, Tillmann Boeckel, Jurgen Schaffner-Bielich

We have investigated effects of the QCD phase transition on the relic GW spectrum applying several equations of state for the strongly interacting matter: Besides the bag model, which describes a first order transition, we use recent data from lattice calculations featuring a crossover. Finally, we include a short period of inflation during the transition wh

Pulkit Grover, Kristen Ann Woyach, Anant Sahai

Traditional communication theory focuses on minimizing transmit power. However, communication links are increasingly operating at shorter ranges where transmit power can be significantly smaller than the power consumed in decoding. This paper models the required decoding power and investigates the minimization of total system power from two complementary per

Gentaro Watanabe, Franco Dalfovo, Lev P. Pitaevskii, Sandro Stringari

We study the effects of an external periodic potential on the critical velocity of a superfluid Fermi gas in the crossover between the Bardeen-Cooper-Schrieffer (BCS) phase and Bose-Einstein condensation (BEC). We numerically solve the Bogoliubov-de Gennes equations to model a three-dimensional (3D) gas of ultracold atoms in the superfluid phase flowing thro

Sébastien Nedjar, Fabien Pesci, Lotfi Lakhal, Rosine Cicchetti

The skyline concept has been introduced in order to exhibit the best objects according to all the criterion combinations and makes it possible to analyse the relationships between skyline objects. Like the data cube, the skycube is so voluminous that reduction approaches are really necessary. In this paper, we define an approach which partially materializes

Xavier Caruso

Let p be an odd prime number and K be a p-adic field. In this paper, we develop an analogue of Fontaine's theory of (phi,Gamma)-modules replacing the p-cyclotomic extension by the extension K_infty obtained by adding to K a compatible system of p^n-th roots of a fixed uniformizer pi of K. As a result, we obtain a new classification of p-adic representations

Massimo Brescia, Giuseppe Longo, George S. Djorgovski, Stefano Cavuoti

Nowadays, many scientific areas share the same need of being able to deal with massive and distributed datasets and to perform on them complex knowledge extraction tasks. This simple consideration is behind the international efforts to build virtual organizations such as, for instance, the Virtual Observatory (VObs). DAME (DAta Mining & Exploration) is an in

Ville Bergholm, Jacob D. Biamonte

In this paper, we extend past work done on the application of the mathematics of category theory to quantum information science. Specifically, we present a realization of a dagger-compact category that can model finite-dimensional quantum systems and explicitly allows for the interaction of systems of arbitrary, possibly unequal, dimensions. Hence our framew

Alexander Kusenko

Combined recent data from cosmic-ray detectors and gamma-ray detectors have produced some surprising insights regarding the sources of ultrahigh-energy cosmic rays (UHECRs), magnetic fields inside and outside the Milky Way, and the universal photon backgrounds. The energy-dependent composition of UHECRs implies a non-negligible contribution of sources locate

Kiril Datchev, Hamid Hezari, Ivan Ventura

We prove that the spectrum of an n-dimensional semiclassical radial Schrödinger operator determines the potential within a large class of potentials for which we assume no symmetry or analyticity. Our proof is based on the first two semiclassical trace invariants and on the isoperimetric inequality.

Nuno Cardoso, Pedro Bicudo

In this work we explore the performance of CUDA in quenched lattice SU(2) simulations. CUDA, NVIDIA Compute Unified Device Architecture, is a hardware and software architecture developed by NVIDIA for computing on the GPU. We present an analysis and performance comparison between the GPU and CPU in single and double precision. Analyses with multiple GPUs and

Y. Japha, Y. B. Band

The low energy properties of a trapped bose gas split by a potential barrier are determined over the whole range of barrier heights. We derive a self-consistent two-mode model which reduces, for large $N$, to a Bogoliubov model for low barriers and to a Josephson model for any (asymmetric) double well potential, with explicitly calculated tunneling and pair

Lisa Borland, Yoan Hassid

Cross-sectional signatures of market panic were recently discussed on daily time scales in [1], extended here to a study of cross-sectional properties of stocks on intra-day time scales. We confirm specific intra-day patterns of dispersion and kurtosis, and find that the correlation across stocks increases in times of panic yielding a bimodal distribution fo

Min Yu, Dallas R. Trinkle

We propose an efficient, accurate method to integrate the basins of attraction of a smooth function defined on a general discrete grid, and apply it to the Bader charge partitioning for the electron charge density. Starting with the evolution of trajectories in space following the gradient of charge density, we derive an expression for the fraction of space

Weinan E, Jianfeng Lu, Xu Yang

The behavior of interacting electrons in a perfect crystal under macroscopic external electric and magnetic fields is studied. Effective Maxwell equations for the macroscopic electric and magnetic fields are derived starting from time-dependent density functional theory. Effective permittivity and permeability coefficients are obtained.

Anas Chaaban, Aydin Sezgin

We consider the 3-user Gaussian interference channel and provide an outer bound on its capacity region. Under some conditions, which we call the mixed strong-very strong interference conditions, this outer bound is achievable. These conditions correspond to the case where at each receiver, one transmitter is causing strong interference and the other is causi

Thomas Fischbacher, Krzysztof Pilch, Nicholas P. Warner

We establish analytically that the potential of N=8 supergravity in four dimensions has a new N=1 supersymmetric critical point with U(1) x U(1) symmetry. We work within a consistent N=1 supersymmetric truncation and obtain the holographic flow to this new point from the N=8 critical point. The operators that drive the flow in the dual field theory are ident

S. A. Parameswaran, S. A. Kivelson, S. L. Sondhi, B. Z. Spivak

The Pfaffian phase of electrons in the proximity of a half-filled Landau level is understood to be a p+ip superconductor of composite fermions. We consider the properties of this paired quantum Hall phase when the pairing scale is small, i.e. in the weak-coupling, BCS, limit, where the coherence length is much larger than the charge screening length. We find

H. E. S. S. Collaboration, F. Acero, F. Aharonian, A. G. Akhperjanian

Context: The detection of gamma-rays in the very-high-energy (VHE) range (100 GeV-100 TeV) offers the possibility of studying the parent population of ultrarelativistic particles found in astrophysical sources, so it is useful for understanding the underlying astrophysical processes in nonthermal sources. Aim: The discovery of the VHE gamma-ray source HESS J

Ji-Hyun Kim, Jianshu Cao

Using a classical master equation that describes energy transfer over a given lattice, we explore how energy transfer efficiency along with the photon capturing ability depends on network connectivity, on transfer rates, and on volume fractions - the numbers and relative ratio of fluorescence chromophore components, e.g., donor (D), acceptor (A), and bridge

Yuri Berest, George Khachatryan, Ajay Ramadoss

We present a simple algebraic construction of the (non-abelian) derived functors DRep_n(A) of the representation scheme Rep_n(A), parametrizing the n-dimensional representations of an associative algebra A. We construct a related derived version of the representation functor introduced recently by M. Van den Bergh and, as an application, compute the derived

V. K. Dugaev, M. Inglot, E. Ya. Sherman, J. Barnas

We propose a mechanism of spin Hall effect in two-dimensional electron gas with spatially random Rashba spin-orbit interaction. The calculations based on the Kubo formalism and kinetic equation show that in contrast to the constant spin-orbit coupling, spin Hall conductivity in the random spin-orbit field is not totally suppressed by the potential impurity s

William G. Mathews, Fulai Guo

In Cygnus A and other classical FR II double radio sources, powerful opposing jets from the cores of halo-centered galaxies drive out into the surrounding cluster gas, forming hotspots of shocked and compressed cluster gas at the jet extremities. The moving hotspots are sandwiched between two shocks. An inner-facing shock receives momentum and cosmic rays fr

Tsunekazu Nishinaka

We prove that every group ring of a non-abelian locally free group which is the union of an ascending sequence of free groups is primitive. In particular, every group ring of a countable non-abelian locally free group is primitive. In addition, by making use of the result, we give a necessary and sufficient condition for group rings of ascending HNN extensio

Steven Spallone

Let G be a reductive algebraic group over Q, and suppose that Gamma is an arithmetic subgroup of G(R) defined by congruence conditions. A basic problem in arithmetic is to determine the multiplicities of discrete series representations in L^2(Gamma \ G(R)), and in general to determine the traces of Hecke operators on these spaces. In this paper we give a con

M. Misiak

Radiative decays of the B meson are known to provide important constraints on the MSSM and many other realistic new physics models in the sub-TeV range. The inclusive branching ratio BR(B -> Xs gamma) being the key observable is currently measured to about 7% accuracy. Reaching a better precision on the theory side is a challenge both for the perturbative QC

Daniela Dragoman

The propagation of charge carriers in graphene is compared to that in type II/III heterostructures for which a two-band Kane model is appropriate. In particular, conditions for a quantitative analogy between these two cases are searched for, and found to be quite restrictive. The analysis in this paper shows that the essential property of graphene is not the

Markus Haase

A general approach to transference principles for discrete and continuous operator (semi)groups is described. This allows to recover the classical transference results of Calderón, Coifman and Weiss and of Berkson, Gillespie and Muhly and the more recent one of the author. The method is applied to derive a new transference principle for (discrete and continu

Pablo Sprechmann, Ignacio Ramirez, Pablo Cancela, Guillermo Sapiro

A collaborative framework for detecting the different sources in mixed signals is presented in this paper. The approach is based on C-HiLasso, a convex collaborative hierarchical sparse model, and proceeds as follows. First, we build a structured dictionary for mixed signals by concatenating a set of sub-dictionaries, each one of them learned to sparsely mod

S. L. O&#39;Dell, R. J. Brissenden, W. N. Davis, R. F. Elsner

High-energy astrophysics is a relatively young scientific field, made possible by space-borne telescopes. During the half-century history of x-ray astronomy, the sensitivity of focusing x-ray telescopes-through finer angular resolution and increased effective area-has improved by a factor of a 100 million. This technological advance has enabled numerous exci

Prabhu Ramachandran, Gaël Varoquaux

Mayavi is an open-source, general-purpose, 3D scientific visualization package. It seeks to provide easy and interactive tools for data visualization that fit with the scientific user&#39;s workflow. For this purpose, Mayavi provides several entry points: a full-blown interactive application; a Python library with both a MATLAB-like interface focused on easy

Hector Alarcon, Osvanny Ramos, Loïc Vanel, Franck Vittoz

We report on a cellular pattern which spontaneously forms at the surface of a thin layer of a cohesive granular material submitted to in-plane stretching. We present a simple model in which the mechanism responsible of the instability is the ``strain softening&#39;&#39; exhibited by humid granular materials above a typical strain. Our analysis indicates that

R. R. Nair, P. Blake, J. R. Blake, R. Zan

We demonstrate the application of graphene as a support for imaging individual biological molecules in transmission electron microscope (TEM). A simple procedure to produce free-standing graphene membranes has been designed. Such membranes are extremely robust and can support practically any sub-micrometer object. Tobacco mosaic virus has been deposited on g

Muhammad Ibrahim Channa, Kazi M. Ahmed

The natural or man-made disaster demands an efficient communication and coordination among first responders to save life and other community resources. Normally, the traditional communication infrastructures such as land line or cellular networks are damaged and don&#39;t provide adequate communication services to first responders for exchanging emergency re

Adam J. Christopherson, Karim A. Malik

In this special issue article, based on the talk with the same title in session B5 (Theoretical and Mathematical Cosmology) at GR19, we review the case of vorticity generation in cosmology using cosmological perturbation theory. We show that, while at linear order the vorticity evolution equation has no source term in the absence of anisotropic stress, at se

A. Bouaouda, R. Zarrouki, H. Chakir, M. Bennai

We consider a supersymmetric hybrid inflation in the framework of the Randall-Sundrum type II Braneworld model. We drive an analytical expression for the scalar potential and find that the F-term dominates hybrid inflation process. We show that for some value of Brane tension we can eliminate the fine tuning problem related to coupling constant k of the pote

Franco Pellegrini, Giuseppe E. Santoro, Erio Tosatti

We identify the mechanism of energy dissipation relevant to spin-sensitive nanomechanics including the recently introduced magnetic exchange force microscopy, where oscillating magnetic tips approach surface atomic spins. The tip-surface exchange couples spin and atom coordinates, leading to a spin-phonon problem with Caldeira-Leggett type dissipation. In th

Wolfgang Karcher

We consider random fields admitting a spectral representation with infinitely divisible integrator and prove some of their properties.

A. M. Snigirev

The double parton distribution functions are investigated in the region of small longitudinal momentum fractions in the leading logarithm approximation of perturbative QCD. It is shown that these functions have the factorization property in the case of one slow and one fast parton.

Clive Ruggles

From an anthropological point of view, the whole concept of a &#34;path of progress&#34; in astronomical discovery is anathema, since it implicitly downgrades other cultural perspectives, such as the many &#34;indigenous cosmologies&#34; that still exist in the modern world. By doing so, one risks provoking those who hold them and-as is most obvious in place

Huseyin Kurt, Karsten Rode, Munuswamy Venkatesan, Plamen Stanislavov Stamenov

Ferrimagnetic Mn3Ga exhibits a unique combination of low saturation magnetization (Ms = 0.11 MA m-1) and high perpendicular anisotropy with a uniaxial anisotropy constant of Ku = 0.89 MJ m-3. Epitaxial c-axis films exhibit spin polarization as high as 58%, measured using point contact Andreev reflection. These epitaxial films will be able to support thermall

Byoung S. Ham

Using on-demand coherence conversion via optical locking in conventional stimulated (three-pulse) photon echoes, ultralong, ultraefficient photon storage has been observed in a rare-earth Pr3+ doped Y2SiO5, where storage time is several orders of magnitude longer and retrieval efficiency is enhanced by fifty times. Compared with the same method applied to tw

Ratan Lal

Considering a theoretical hysteresis loop within the Kim model for the Kim constant $H_0$ = 0 it has been found that the expression of $H_0$ obtained in Lal [R. Lal, Physica C 470 (2010) 281] provides a nonzero value 0.3424$H_p$ for this constant. ($H_p$ is full penetration field.) This different value of the Kim constant for the same hysteresis loop has bee

Qingchun Zhao, Hongxi Yin

Chaotic communications based on semiconductor lasers have aroused great research interest since 1990s. Physical-layer encryption using chaotic lasers is an alternative to transmit message rapidly and confidentially. There are some practical devices and setups for optical chaotic communications, which are intuitively considered to be secure. However, there is

Zhen-Xing Liu, Ze-Qian Chen

We investigate the properties of rotating asymptotically flat black ring solutions in five-dimensional Einstein-Maxwell-dilaton gravity with the Kaluza-Klein coupling. Within the quasilocal formalism, the balance condition for these solutions is derived by using the conservation of the renormalized boundary stress-energy tensor, which is a new method propose

Jens Klein

This thesis is concerned with problems related to Synthetic Aperture Radar (SAR). The thesis is structured as follows: The first chapter explains what SAR is, and the physical and mathematical background is illuminated. The following chapter points out a problem with a divergent integral in a common approach and proposes an improvement. Numerical comparisons

Salah A. Aly, Nirwan Ansari, Anwar I. Walid, H. Vincent Poor

There have been several approaches to provisioning traffic between core network nodes in Internet Service Provider (ISP) networks. Such approaches aim to minimize network delay, increase network capacity, and enhance network security services. MATE (Multipath Adaptive Traffic Engineering) protocol has been proposed for multipath adaptive traffic engineering

Andriy V. Kityk, Patrick Huber

Optical birefringence measurements on a rod-like liquid crystal (8OCB), imbibed in silica channels (7 nm diameter), are presented and compared to the thermotropic bulk behavior. The orientational and positional order of the confined liquid evolves continuously at the paranematic-to-nematic and sizeably broadened at the nematic-to-smectic order transition, re

Pulkit Grover, Anant Sahai

There has been substantial progress recently in understanding toy problems of purely implicit signaling. These are problems where the source and the channel are implicit -- the message is generated endogenously by the system, and the plant itself is used as a channel. In this paper, we explore how implicit and explicit communication can be used synergistical

Jun Yao, Lin Zhong, Douglas Natelson, James M. Tour

Silicon oxide (SiOx) has been widely used in many electronic systems as a supportive and insulating medium. Here we demonstrate various electrical phenomena such as negative differential resistance, resistive switching and current hysteresis intrinsic to a thin layer of SiOx. These behaviors can largely mimic numerous electrical phenomena observed in molecul

Evan S. Gawlik, Patrick Mullen, Dmitry Pavlov, Jerrold E. Marsden

This study derives geometric, variational discretizations of continuum theories arising in fluid dynamics, magnetohydrodynamics (MHD), and the dynamics of complex fluids. A central role in these discretizations is played by the geometric formulation of fluid dynamics, which views solutions to the governing equations for perfect fluid flow as geodesics on the

Pierre R. Bertrand, Mehdi Fhima, Arnaud Guillin

We investigate here the Central Limit Theorem of the Increment Ratio Statistic of a multifractional Brownian motion, leading to a CLT for the time varying Hurst index. The proofs are quite simple relying on Breuer-Major theorems and an original freezing of time strategy. A simulation study shows the goodness of fit of this estimator.

Paul Iachkine, Sophie Barré, Kostia Roncin, Jean-Michel Kobus

This paper presents the experimental set-up and the analysis tools developed for the performance evaluation in sailing. The measurement system is composed of sensors for the position and attitude of the sail boat, sensors for the wind measurement and some tools for the coach.

Marc A. A. Van Leeuwen

In this note we observe that a bijection related to Littelmann&#39;s root operators (for type $A_1$) transparently explains the well known enumeration by length of walks on $\N$ (left factors of Dyck paths), as well as some other enumerative coincidences. We indicate a relation with bijective solutions of Bertrand&#39;s ballot problem: those can be mechanica

Danilo Valeros Bernardo, Doan B Hoang

The emergence of various technologies has since pushed researchers to develop new protocols that support high density data transmissions in Wide Area Networks. Many of these protocols are TCP protocol variants, which have demonstrated better performance in simulation and several limited network experiments but have limited practical applications because of i

Joachim Escher, Boris Kolev, Marcus Wunsch

We provide rigorous evidence of the fact that the modified Constantin-Lax-Majda equation modeling vortex and quasi-geostrophic dynamics describes the geodesic flow on the subgroup of orientation-preserving diffeomorphisms fixing one point, with respect to right-invariant metric induced by the homogeneous Sobolev norm $H^{1/2}$ and show the local existence of

X. -W. Guan, M. T. Batchelor

We demonstrate that the thermodynamics of one-dimensional Lieb-Liniger bosons can be accurately calculated in analytic fashion using the polylog function in the framework of the thermodynamic Bethe ansatz. The approach does away with the need to numerically solve the thermodynamic Bethe ansatz (Yang-Yang) equation. The expression for the equation of state al

Toshihiro Yamaguchi

Let $X$ be a simply connected CW complex with finite rational cohomology. For the finite quotient set of rationalized orbit spaces of $X$ obtained by almost free toral actions, ${\mathcal T}_0(X)=\{[Y_i] \}$, induced by an equivalence relation based on rational toral ranks, we order as $[Y_i]<[Y_j]$ if there is a rationalized Borel fibration $Y_i\to Y_j\to B

S. Bogatyi, V. Valov

If $g$ is a map from a space $X$ into $\mathbb R^m$ and $z\not\in g(X)$, let $P_{2,1,m}(g,z)$ be the set of all lines $Π^1\subset\mathbb R^m$ containing $z$ such that $|g^{-1}(Π^1)|\geq 2$. We prove that for any $n$-dimensional metric compactum $X$ the functions $g\colon X\to\mathbb R^m$, where $m\geq 2n+1$, with $\dim P_{2,1,m}(g,z)\leq 0$ for all $z\not\in

Ronny Thomale, Benoit Estienne, Nicolas Regnault, B. Andrei Bernevig

We provide a detailed description of a new symmetry structure of the monomial (Slater) expansion coefficients of bosonic (fermionic) fractional quantum Hall states first obtained in Ref. 1, which we now extend to spin-singlet states. We show that the Haldane-Rezayi spin-singlet state can be obtained without exact diagonalization through a differential equati

G. Ramos-Larios, J. P. Phillips, L. C. Cuesta

We present imaging and spectroscopy of NGC 40 acquired using the Spitzer Space Telescope (Spitzer), and the Infrared Space observatory (ISO). These are used to investigate the nature of emission from the central nebular shell, from the nebular halo, and from the associated circumnebular rings. It is pointed out that a variety of mechanisms may contribute to

Alexander Panchenko, Lyudmyla L. Barannyk, Robert P. Gilbert

We study the closure problem for continuum balance equations that model mesoscale dynamics of large ODE systems. The underlying microscale model consists of classical Newton equations of particle dynamics. As a mesoscale model we use the balance equations for spatial averages obtained earlier by a number of authors: Murdoch and Bedeaux, Hardy, Noll and other

Harri Hakula, Antti Rasila, Matti Vuorinen

Moduli of rings and quadrilaterals are frequently applied in geometric function theory, see e.g. the Handbook by Kühnau. Yet their exact values are known only in a few special cases. Previously, the class of planar domains with polygonal boundary has been studied by many authors from the point of view of numerical computation. We present here a new $hp$-FEM

Neil D. Lawrence

We introduce a new perspective on spectral dimensionality reduction which views these methods as Gaussian Markov random fields (GRFs). Our unifying perspective is based on the maximum entropy principle which is in turn inspired by maximum variance unfolding. The resulting model, which we call maximum entropy unfolding (MEU) is a nonlinear generalization of p

Shigenori Tanaka

The multiparticle density matrices for degenerate, ideal Fermi gas system in any dimension are calculated. The results are expressed as a determinant form, in which a correlation kernel plays a vital role. Interestingly, the correlation structure of one-dimensional Fermi gas system is essentially equivalent to that observed for the eigenvalue distribution of

Gebhard Böckle, Ralf Butenuth

Let $Λ$ be a maximal $\mathbb{F}_q[T]$-order in a division quaternion algebra over $\mathbb{F}_q(T)$ which is split at the place $\infty$. The present article gives an algorithm to compute a fundamental domain for the action of the group of units $Λ^*$ on the Bruhat-Tits tree $\mathcal{T}$ associated to $PGL_2(\mathbb{F}_q((1/T)))$. This action is a function

Serdar Yüksel

The optimal causal coding of a partially observed Markov process is studied, where the cost to be minimized is a bounded, non-negative, additive, measurable single-letter function of the source and the receiver output. A structural result is obtained extending Witsenhausen&#39;s and Walrand-Varaiya&#39;s structural results on optimal real-time coders to a pa

Alin Stancu

A relative derived category for the category of modules over a presheaf of algebras is constructed to identify the relative Yoneda and Hochschild cohomologies with its homomorphism groups. The properties of a functor between this category and the relative derived category of modules over the algebra associated to the presheaf are studied. We obtain a general

Teng Liu, Jun-Xian Wang

We compile a sample of 89 Seyfert galaxies with both [OIV] 25.89 um line luminosities observed by Spitzer IRS and X-ray spectra observed by XMM EPIC. Using [OIV] emission as proxy of AGN intrinsic luminosity, we find that although type 2 AGNs have higher line equivalent width, the narrow Fe Kalpha line in Compton-Thin and Compton-Thick Seyfert 2 galaxies are

Dmitry Borisyuk, Alexander Kobushkin

We calculate two-photon exchange amplitude for the elastic electron-pion scattering in the dispersion-relation inspired approach, including both elastic and inelastic contributions. The latter was modelled as a sum of ρand b_1(1235) meson contributions. We find that at Q^2 < 2 GeV^2 the elastic contribution is dominant, similarly to electron-proton scatterin

Ajay Ramadoss, Xiang Tang

We study Hochschild (co)homology groups of the Dunkl operator quantization of $\Z_2$-singularity constructed by Halbout and Tang. Further, we study traces on this algebra and prove a local algebraic index formula.

Daniel R. Gulotta, Christopher P. Herzog, Matthias Kaminski

Using the gravity side of the AdS/CFT correspondence, we investigate the analytic properties of thermal retarded Green&#39;s functions for scalars, conserved currents, the stress tensor, and massless fermions. We provide some results concerning their large and small frequency behavior and their pole structure. From these results, it is straightforward to pro

A. Brandenburg

Using simulations of helically driven turbulence, it is shown that the ratio of kinetic to magnetic energy dissipation scales with the magnetic Prandtl number in power law fashion with an exponent of approximately 0.6. Over six orders of magnitude in the magnetic Prandtl number the magnetic field is found to be sustained by large-scale dynamo action of alpha

Michael Dine, Guido Festuccia, John Kehayias, Weitao Wu

While axions seem ubiquitous in critical string theories, whether they might survive in any string theoretic description of nature is a difficult question. With some mild assumptions, one can frame the issues in the case that there is an approximate supersymmetry below the underlying string scale. The problem of axions is then closely tied to the question of

R. N. Caldeira Costa, Marika Taylor

Deformation of any d-dimensional conformal field theory by a constant null source for a vector operator of dimension (d + z -1) is exactly marginal with respect to anisotropic scale invariance, of dynamical exponent z. The holographic duals to such deformations are AdS plane waves, with z=2 being the Schrodinger geometry. In this paper we explore holography

Michael Boylan-Kolchin, Gurtina Besla, Lars Hernquist

We examine Milky Way-Magellanic Cloud systems selected from the Millennium-II Simulation in order to place the orbits of the Magellanic Clouds in a cosmological context. Our analysis shows that satellites massive enough to be LMC analogs are typically accreted at late times. Moreover, those that are accreted at early times and survive to the present have orb

Matthew Hayes, Daniel Schaerer, Goran Ostlin, J. Miguel Mas-Hesse

The Ly-alpha emission line has been proven a powerful tool by which to study evolving galaxies at the highest redshifts. However, in order to use Lya as a physical probe of galaxies, it becomes vital to know the Lya escape fraction (fescLya). Unfortunately, due to the resonant nature of Lya, fescLya may vary unpredictably and requires empirical measurement.

A. Papitto, A. D&#39;Ai&#39;, S. Motta, A. Riggio

We present an analysis of the spin and orbital properties of the newly discovered accreting pulsar IGR J17480-2446, located in the globular cluster Terzan 5. Considering the pulses detected by the Rossi X-ray Timing Explorer at a period of 90.539645(2) ms, we derive a solution for the 21.27454(8) hr binary system. The binary mass function is estimated to be

R. S. Schnerr, H. C. Spruit

In addition to the `facular&#39; brightening of active regions, the quiet Sun also contains a small scale magnetic field with associated brightenings in continuum radiation. We measure this contribution of quiet regions to the Sun&#39;s brightness from high spatial resolution (0&#34;16-0&#34;32) observations of the Swedish 1-m Solar Telescope (SST) and Hinod

Volker Sluka, Attila Kakay, Alina M. Deac, Daniel E. Bürgler

We report experimental and analytical work on spin-transfer torque induced vortex dynamics in metallic nanopillars with in-plane magnetized layers. We study nanopillars with a diameter of 150 nm, containing two Fe layers with a thickness of 15 nm and 30 nm respectively, separated by a 6 nm Ag spacer. The sample geometry is such that it allows for the formati

N. Arcozzi, R. Rochberg, E. Sawyer, B. D. Wick

We investigate connections between potential theories on a Ahlfors-regular metric space X, on a graph G associated with X, and on the tree T obtained by removing the &#34;horizontal edges&#34; in G. Applications to the calculation of set capacity are given.

Matteo Cristani, Erisa Karafili, Luca Viganò

Similar to what happens between humans in the real world, in open multi-agent systems distributed over the Internet, such as online social networks or wiki technologies, agents often form coalitions by agreeing to act as a whole in order to achieve certain common goals. However, agent coalitions are not always a desirable feature of a system, as malicious or