July 2013 arXiv papers

S. Jouvel, O. Host, O. Lahav, S. Seitz

The Cluster Lensing And Supernovae survey with Hubble (CLASH) is an Hubble Space Telescope (HST) Multi-Cycle Treasury program observing 25 massive galaxy clusters. CLASH observations are carried out in 16 bands from UV to NIR to derive accurate and reliable estimates of photometric redshifts. We present the CLASH photometric redshifts and study the photometr

Roger R. Sakhel, Asaad R. Sakhel, Humam B. Ghassib

We investigate numerically the momentum density and phase maps $-$in coordinate and momentum space$-$ of a two dimensional Bose-Einstein condensate (BEC) excited by a moving red-detuned laser potential. The BEC is confined in a harmonic trap cutoff by hard walls. The system and excitation scheme are as in our previous work (Roger R. Sakhel {\it et al.} to ap

Gerasimos Rigopoulos, Wessel Valkenburg

We examine the deviation of Cold Dark Matter particle trajectories from the Newtonian result as the size of the region under study becomes comparable to or exceeds the particle horizon. To first order in the gravitational potential, the general relativistic result coincides with the Zel'dovich approximation and hence the Newtonian prediction on all scale

Joshua V. Cardenzana

Current gamma-ray observatories have made substantial advances in the study of potential cosmic ray accelerators such as supernova remnants (SNRs), but the study of cosmic rays in flight from their parent accelerators remains a topic of great interest. The Fermi Gamma-ray Space Telescope (FGST) discovered a four square degree region of gamma-ray emission bet

Daniel H. McIntosh, Cory Wagner, Andrew Cooper, Eric F. Bell

We use the Sloan Digital Sky Survey to investigate the properties of massive elliptical galaxies in the local Universe (z\leq0.08) that have unusually blue optical colors. Through careful inspection, we distinguish elliptical from non-elliptical morphologies among a large sample of similarly blue galaxies with high central light concentrations (c_r\geq2.6).

Vernon Barger, Lisa L. Everett, Heather E. Logan, Gabe Shaughnessy

The discovery at the LHC of a scalar particle with properties that are so far consistent with the SM Higgs boson is one of the most important advances in the history of particle physics. The challenge of future collider experiments is to determine whether its couplings will show deviations from the SM Higgs, as this would indicate new physics at the TeV scal

J. William Helton, Igor Klep, Christopher S. Nelson

By a result of Helton and McCullough, open bounded convex free semialgebraic sets are exactly open (matricial) solution sets D_L of a linear matrix inequality (LMI) L(X)>0. This paper gives a precise algebraic certificate for a polynomial being nonnegative on a convex semialgebraic set intersect a variety, a so-called "Perfect" Positivstellensatz. For exampl

Andrew W. Smith

Since the commissioning of the array in Spring 2007, the VERITAS array (sensitive in the 0.1-50 TeV energy range) has acquired over 300 hours of observations investigating the TeV emission from X-ray binary star systems, in particular focusing on the known TeV binary targets LS I +61 303 and HESS J0632+057. Both TeV binaries have been monitored by VERITAS fo

Andres A. Reynoso, Diego Frustaglia

For systems that can be modeled as a single-particle lattice extended along a privileged direction as, e.g., quantum wires, the so-called eigenvalue method provides full information about the propagating and evanescent modes as a function of energy. This complex-band structure method can be applied either to lattices consisting of an infinite succession of i

Jeffrey Giansiracusa, Noah Giansiracusa

We introduce a scheme-theoretic enrichment of the principal objects of tropical geometry. Using a category of semiring schemes, we construct tropical hypersurfaces as schemes over idempotent semirings such as $\mathbb{T} = (\mathbb{R}\cup \{-\infty\}, \mathrm{max}, +)$ by realizing them as solution sets to explicit systems of tropical equations that are uniq

Brian C. Hall

This paper describes results of the author with B. K. Driver and T. Kemp concerning the large-N limit of the Segal--Bargmann transform for the unitary group U(N). We consider the transform on matrix-valued functions that are polynomials in a single variable in U(N). We show that in the large-N limit, the transform maps functions of this type to single-variab

Ralph Tanbourgi, Sarabjot Singh, Jeffrey G. Andrews, Friedrich K. Jondral

This paper presents a tractable model for analyzing non-coherent joint transmission base station (BS) cooperation, taking into account the irregular BS deployment typically encountered in practice. Besides cellular-network specific aspects such as BS density, channel fading, average path loss and interference, the model also captures relevant cooperation mec

Laurent Freidel, Jonathan Ziprick

It is well known that the SU(2)-gauge invariant phase space of loop gravity can be represented in terms of twisted geometries. These are piecewise-linear-flat geometries obtained by gluing together polyhedra, but the resulting geometries are not continuous across the faces. Here we show that this phase space can also be represented by continuous, piecewise-f

Eugene Feinberg, Xiaoxuan Zhang

This paper studies optimal switching on and o? of the entire service capacity of an M/M/Infinity queue with holding, running and switching costs where the running costs depend only on whether the system is running or not. The goal is to minimize average costs per unit time. The main result is that an average-optimal policy either always runs the system or is

M. P. Ehrlichman, W. Hartung, B. Heltsley, D. P. Peterson

Intrabeam scattering (IBS) limits the emittance and single-bunch current that can be achieved in electron or positron storage ring colliders, damping rings, and light sources. Much theoretical work on IBS exists, and while the theories have been validated in hadron and ion machines, the presence of strong damping makes IBS in lepton machines a different phen

J. Hooker, W. G. Newton, Bao-An Li

In order to assess the ability of purely crust-driven glitch models to match the observed glitch activity in the Vela pulsar, we conduct a systematic analysis of the dependence of the fractional moment of inertia of the inner crustal neutrons on the stiffness of the nuclear symmetry energy at saturation density $L$. We take into account both crustal entrainm

Mohamed M. Anber

The confinement problem remains one of the most difficult problems in theoretical physics. An important step toward the solution of this problem is the Polyakov's work on abelian confinement. The Georgi-Glashow model is a natural testing ground for this mechanism which has been surprising us by its richness and wide applicability. In this work, we shed l

Gustavo Marques Tavares, Martin Schmaltz, Witold Skiba

It has been suggested that electroweak symmetry breaking in the Standard Model may be natural if the Standard Model merges into a conformal field theory (CFT) at short distances. In such a scenario the Higgs mass would be protected from quantum corrections by the scale invariance of the CFT. In order for the Standard Model to merge into a CFT at least one ne

Tanushree Basak, Tanmoy Mondal

We study the $B-L$ gauge extension of the Standard Model which contains a singlet scalar and three right-handed neutrinos. The vacuum expectation value of the singlet scalar breaks the $U(1)_{B-L}$ symmetry. Here the third generation right-handed neutrino is qualified as the dark matter candidate, as an artifact of $Z_2$-charge assignment. Relic abundance of

S. Ruhallah Ahmadi

Suppose $G$ is a connected complex Lie group and $Γ$ is a discrete subgroup such that $X := G/Γ$ is Kähler and the codimension of the top non--vanishing homology group of $X$ with coefficients in $\mathbb Z_2$ is less than or equal to two. We show that $G$ is solvable and a finite covering of $X$ is biholomorphic to a product $C\times A$, where $C$ is a Cous

Oleg Y. Gnedin, Jeremiah P. Ostriker, Scott Tremaine

We revisit the hypothesis that dense galactic nuclei are formed from inspiraling globular clusters. Recent advances in understanding of the continuous formation of globular clusters over cosmic time and the concurrent evolution of the galaxy stellar distribution allow us to construct a simple model that matches the observed spatial and mass distributions of

Ariel R. Zhitnitsky

We conjecture that the phase transitions in QCD at large number of colours N\gg 1 is triggered by the drastic change in the instanton density. As a result of it, all physical observables also experience some sharp modification in the θbehaviour. This conjecture is motivated by the holographic model of QCD where confinement -deconfinement phase transition ind

Ryan M. O'Leary, Joshua Burkart

We explore the tidal excitation of stellar modes in binary systems using Kepler observations of the remarkable eccentric binary KOI-54 (HD 187091; KIC 8112039), which displays strong ellipsoidal variation as well as a variety of linear and nonlinear pulsations. We report the amplitude and phase of over 120 harmonic and anharmonic pulsations in the system. We

Avery E. Broderick, Christoph Pfrommer, Ewald Puchwein, Philip Chang

In principle, the angular anisotropy in the extragalactic gamma-ray background (EGRB) places severe constraints upon putative populations of unresolved gamma-ray point sources. Existing estimates of the EGRB anisotropy have been constructed by excising known point sources, e.g., taken from the First or 2 Year Fermi-LAT Source Catalog (1FGL or 2FGL, respectiv

Hagai Netzer, Rivay Mor, Benny Trakhtenbrot, Ohad Shemmer

We report Herschel Spitzer and Wise observations of 44 z=4.8 optically selected active galactic nuclei (AGNs). This sample contains the highest mass black holes (BHs) at this redshift. Ten of the objects were detected by Herschel and five show emission that is not associated with the AGNs. The star formation (SF) luminosity (LSF) obtained by fitting the spec

A. Bueno, M. Masip, P. Sánchez-Lucas, N. Setzer

Dark matter collisions with heavy nuclei (Xe, Ge, Si, Na) may produce recoils observable at direct-search experiments. Given that some of these experiments are yielding conflicting information, however, it is worth asking if physics other than dark matter may produce similar nuclear recoils. We examine under what conditions an atmospherically-produced neutra

Stefan Hofmann, Florian Niedermann, Robert Schneider

According to folklore in general relativity, the Weyl tensor can be decomposed into parts corresponding to Newton-like, incoming and outgoing wavelike field components. It is shown here that this one-to-one correspondence does not hold for space-time geometries with cylindrical isometries. This is done by investigating some well-known exact solutions of Eins

David M. Kipping

Stellar limb darkening affects a wide range of astronomical measurements and is frequently modelled with a parametric model using polynomials in the cosine of the angle between the line of sight and the emergent intensity. Two-parameter laws are particularly popular for cases where one wishes to fit freely for the limb darkening coefficients (i.e. an uninfor

Lindsey Bosko-Dunbar, Jonathan D. Dunbar, J. T. Hird, Kristen Stagg

All solvable Lie algebras with Heisenberg nilradical have already been classified. We extend this result to a classification of solvable Leibniz algebras with Heisenberg nilradical. As an example, we show the complete classification of all real or complex Leibniz algebras whose nilradical is the 3-dimensional Heisenberg algebra.

M. Cahill-Rowley, J. L. Hewett, A. Ismail, T. G. Rizzo

The 19/20-parameter p(henomenological)MSSM with either a neutralino or gravitino LSP offers a flexible framework for the study of a wide variety of R-parity conserving MSSM SUSY phenomena at the 7, 8 and 14 TeV LHC. Here we present the results of a study of SUSY signatures at these facilities obtained via a fast Monte Carlo 'replication' of the ATLAS

Alice C. Quillen, Ivan Minchev, Sanjib Sharma, Yu-Jing Qin

We explore a second order Hamiltonian vertical resonance model for X-shaped or peanut-shaped galactic bulges. The X-shape is caused by the 2:1 vertical Lindblad resonance with the bar, with two vertical oscillation periods per orbital period in the bar frame. We examine N-body simulations and find that due to the bar slowing down and disk thickening during b

Michael Christ, Taryn C. Flock

Certain rearrangement inequalities of a type considered by Hardy, Riesz, and Brascamp-Lieb-Luttinger are studied. Subsets of the real line that extremize these inequalities are characterized. Our results apply only to special cases, and complement earlier results by Burchard treating other cases. This draft incorporates minor corrections and clarifications.

Daniel Müller

Near the singularity, gravity should be modified to an effective theory, in the same sense as with the Euler-Heisenberg electrodynamics. This effective gravity surmounts to higher derivative theory, and as is well known, a much more reacher theory concerning the solution space. On the other hand, as a highly non linear theory, the understanding of this solut

Hans van Deurzen, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella

We present the calculation of the cross section for Higgs boson production in association with a top quark pair plus one jet, at next-to-leading-order (NLO) accuracy in QCD. All mass dependence is retained without recurring to any approximation. After including the complete NLO QCD corrections, we observe a strong reduction in the scale dependence of the res

Tobias Ekholm, Lenhard Ng

We give a combinatorial description of the Legendrian contact homology algebra associated to a Legendrian link in $S^1\times S^2$ or any connected sum $\#^k(S^1\times S^2)$, viewed as the contact boundary of the Weinstein manifold obtained by attaching 1-handles to the 4-ball. In view of the surgery formula for symplectic homology, this gives a combinatorial

Jose H. Groh, Cyril Georgy, Sylvia Ekstrom

Core-collapse supernova (SN) explosions mark the end of the tumultuous life of massive stars. Determining the nature of their progenitors is a crucial step towards understanding the properties of SNe. Until recently, no progenitor has been directly detected for SN of type Ibc, which are believed to come from massive stars that lose their hydrogen envelope th

Phuc H. Nguyen, Manasvi Lingam

In this paper, we study a family of two-component anisotropic polytropes which model a wide range of spherically symmetric astrophysical systems such as early-type baryonic galaxies. This family is found to contain a large class of models such as the hypervirial family (which satisfy the virial theorem locally), the Plummer and Hernquist models and Navarro-F

Alain Goupil, Marie-Eve Pellerin, Jérôme de Wouters d'Oplinter

The goal of this paper is to study the family of snake polyominoes. More precisely, we focus our attention on the class of partially directed snakes. We establish functional equations and length generating functions of two dimensional, three dimensional and then $N$ dimensional partially directed snake polyominoes. We then turn our attention to partially dir

Igor I. Smolyaninov

Sub-wavelength confinement of light in nonlinear hyperbolic metamaterials due to formation of spatial solitons has attracted much recent attention because of its seemingly counter-intuitive behavior. In order to achieve self-focusing in a hyperbolic wire medium, a nonlinear self-defocusing Kerr medium must be used as a dielectric host. Here we demonstrate th

Christopher D. Carone, Raymundo Ramos

We consider a classically scale-invariant extension of the standard model in which a dark, non-Abelian gauge symmetry is spontaneously broken via the Coleman-Weinberg mechanism. Higgs portal couplings between the dark and standard model sectors provide an origin for the Higgs mass squared parameter and, hence, the electroweak scale. We find that choices for

Sergey Fomin, Dima Grigoriev, Gleb Koshevoy

Subtraction-free computational complexity is the version of arithmetic circuit complexity that allows only three operations: addition, multiplication, and division. We use cluster transformations to design efficient subtraction-free algorithms for computing Schur functions and their skew, double, and supersymmetric analogues, thereby generalizing earlier res

Eileen T. Meyer, Markos Georganopoulos

The X-ray emission mechanism in large-scale jets of powerful radio quasars has been a source of debate in recent years, with two competing interpretations: either the X-rays are of synchrotron origin, arising from a different electron energy distribution than that producing the radio to optical synchrotron component, or they are due to inverse Compton scatte

K. P. Khemchandani, A. Martínez Torres, H. Nagahiro, A. Hosaka

A study of nonstrange meson-baryon systems has been made with the idea of understanding the properties of the low-lying $1/2^-$ $N^*$ and $Δ$ resonances. The coupled channels are built by considering the pseudoscalar and vector mesons together with the octet baryons. The formalism is based on obtaining the interactions from the lowest order chiral Lagrangian

George Dimitrov, Fabian Haiden, Ludmil Katzarkov, Maxim Kontsevich

We study questions motivated by results in the classical theory of dynamical systems in the context of triangulated and A-infinity categories. First, entropy is defined for exact endofunctors and computed in a variety of examples. In particular, the classical entropy of a pseudo-Anosov map is recovered from the induced functor on the Fukaya category. Second,

Christian Sadel

A Herman-Avila-Bochi type formula is obtained for the average sum of the top d Lyapunov exponents over a one-parameter family of G-cocycles, where G is the group that leaves a certain, non-degenerate hermitian form of signature (c,d) invariant. The generic example of such a group is the pseudo-unitary group U(c,d) or in the case c=d, the hermitian-symplectic

Bartlomiej Blaszczyszyn, Miodrag Jovanovic, Mohamed Kadhem Karray

Little's law allows to express the mean user throughput in any region of the network as the ratio of the mean traffic demand to the steady-state mean number of users in this region. Corresponding statistics are usually collected in operational networks for each cell. Using ergodic arguments and Palm theoretic formalism, we show that the global mean user

Teck Seng Koh, S. N. Coppersmith, Mark Friesen

Several logical qubits and quantum gates have been proposed for semiconductor quantum dots controlled by voltages applied to top gates. The different schemes can be difficult to compare meaningfully. Here we develop a theoretical framework to evaluate disparate qubit-gating schemes on an equal footing. We apply the procedure to two types of double-dot qubits

George Grätzer

For a slim, planar, semimodular lattice $L$ and covering square~$S$, G.~Czédli and E.\,T.~Schmidt introduced the fork extension, $L[S]$, which is also a slim, planar, semimodular lattice. We investigate when a congruence of $L$ extends to $L[S]$. We introduce a join-irreducible congruence $\boldsymbolγ(S)$ of $L[S]$. We determine when it is new, in the sense

Benjamin Dadoun, Ralph Neininger

In this paper we study the number of key exchanges required by Hoare's FIND algorithm (also called Quickselect) when operating on a uniformly distributed random permutation and selecting an independent uniformly distributed rank. After normalization we give a limit theorem where the limit law is a perpetuity characterized by a recursive distributional eq

Giulio Magli

The megalithic enclosures of Gobekli Tepe (Urfa, Turkey) are the most ancient sacred structures of stone known so far, dating back to the 10 millennium BC. The possible presence of astronomical targets for these structures is analysed, and it turns out that they may have been oriented, or even originally constructed, to celebrate and successively follow the

Salvatore Tringali

Let $\mathbb{A} = (A, +)$ be a (possibly non-commutative) semigroup. For $Z \subseteq A$ we define $Z^\times := Z \cap \mathbb A^\times$, where $\mathbb A^\times$ is the set of the units of $\mathbb{A}$, and $$γ(Z) := \sup_{z_0 \in Z^\times} \inf_{z_0 \ne z \in Z} {\rm ord}(z - z_0).$$ The paper investigates some properties of $γ(\cdot)$ and shows the follow

Alessio Tamburro

Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the "knee" region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of pene

Armen Bagdasaryan

The partitioning of space by hyperplanes in the context of discrete classification problem is considered. We obtain some relations for the number of partitions and establish a recurrence relation for the maximal number of partitions of R^n by m hyperplanes. We rederive an explicit formula for the number of components into which the space can be partitioned b

Arnold Neumaier

We propose a general form for global analytic equations of state for which close to critical points, the correct universality and scaling behavior is guaranteed. A consequence of the construction is that the generally accepted belief that the dependent scaling field cannot be written as an explicit function of the relevant scaling fields without causing stro

Matt Clay, Christopher J. Leininger, Dan Margalit

We prove that, aside from the obvious exceptions, the mapping class group of a compact orientable surface is not abstractly commensurable with any right-angled Artin group. Our argument applies to various subgroups of the mapping class group---the subgroups generated by powers of Dehn twists and the terms of the Johnson filtration---and additionally to the o

Stephen Pasteris

The junction tree algorithm is a way of computing marginals of boolean multivariate probability distributions that factorise over sets of random variables. The junction tree algorithm first constructs a tree called a junction tree who's vertices are sets of random variables. The algorithm then performs a generalised version of belief propagation on the j

Angela Aguglia, Luca Giuzzi

In $PG(3,q^2)$, with $q$ odd, we determine the possible intersection sizes of a Hermitian surface $\mathcal{H}$ and an irreducible quadric $\mathcal{Q}$ having the same tangent plane $π$ at a common point $P\in{\mathcal Q}\cap{\mathcal H}$.

Martin Klimes

Borel summable divergent series usually appear when studying solutions of analytic ODE near a multiple singular point. Their sum, uniquely defined in certain sectors of the complex plane, is obtained via the Borel--Laplace transformation. This article shows how to generalize the Borel--Laplace transformation in order to investigate bounded solutions of param

Benjamin Zitzer

Quantum gravity (QG) theories over the past fifty years have sought to understand the relationship between the four fundamental interactions. A major insight gained in this area is that all interactions could possibly unify at Planck-scale energies ~10$^{19}$ GeV. A potential consequence of the unification of gravity with the other three interactions would b

Fioralba Cakoni, Nicolas Chaulet, Houssem Haddar

The considered Robin problem can formally be seen as a small perturbation of a Dirichlet problem. However, due to the sign of the impedance value, its associated eigenvalues converge point-wise to $-\infty$ as the perturbation goes to zero. We prove that in this case, Dirichlet eigenpairs are the only accumulation points of the Robin eigenpairs with normaliz

Antoine Canaguier-Durand, Cyriaque Genet, Astrid Lambrecht, Thomas W. Ebbesen

Strongly coupled organic systems are characterized by unusually large Rabi splittings, even in the vacuum state. They show the counter-intuitive feature of a lifetime of the lower polariton state longer than for all other excited states. Here we build up a new theoretical framework to understand the dynamics of such coupled system. In particular, we show tha

Kanghoon Lee, Jeong-Hyuck Park

The section condition in double field theory has been shown to imply that a physical point should be one-to-one identified with a gauge orbit in the doubled coordinate space. Here we show the converse is also true, and continue to explore the idea of `spacetime being doubled yet gauged'. Introducing an appropriate gauge connection, we construct a string

Pranjal Awasthi, Maria Florina Balcan, Philip M. Long

We introduce a new approach for designing computationally efficient learning algorithms that are tolerant to noise, and demonstrate its effectiveness by designing algorithms with improved noise tolerance guarantees for learning linear separators. We consider both the malicious noise model and the adversarial label noise model. For malicious noise, where the

Benjamin Zitzer

Current cosmological models and data suggest the existence of a cold Dark Matter (DM) component, however the nature of DM particles remains unknown. A favored candidate for DM is a Weakly Interacting Massive Particle (WIMP) in the mass range of 50 GeV to greater than 10 TeV. Nearby dwarf spheroidal galaxies (dSphs) are expected to contain a high density of D

Adriana Di Dato

We study the hydrodynamics of relativistic fluids with several conserved global charges (i.e., several species of particles) by performing a Kaluza-Klein dimensional reduction of a neutral fluid on a N-torus. Via fluid/gravity correspondence, this allows us to describe the long-wavelength dynamics of black branes with several Kaluza-Klein charges. We obtain

Jonathan Tyler

Imaging atmospheric Cherenkov telescope (IACT) arrays such as VERITAS are used for ground-based very high-energy gamma-ray astronomy. This is accomplished by the detection and analysis of the Cherenkov light produced by gamma-ray-initiated atmospheric air showers. IACTs also detect the Cherenkov light emitted by individual muons. Identification of these muon

Benjamin Zitzer

VERITAS is an array of imaging atmospheric Cherenkov telescopes sensitive to gamma rays in the energy range between 85 GeV and 30 TeV. The instrument underwent an upgrade of the camera triggers in November 2011. The new systems use 400 MHz Xilinix Virtex-5 FPGAs for the pixel neighbor coincidence logic necessary to produce a camera-level trigger. The upgrade

Łukasz Kosiński, Tomasz Warszawski, Włodzimierz Zwonek

In the paper we study the geometry of semitube domains in $\mathbb C^2$. In particular, we extend the result of Burgués and Dwilewicz for semitube domains dropping out the smoothness assumption. We also prove various properties of non-smooth pseudoconvex semitube domains obtaining among others a relation between pseudoconvexity of a semitube domain and the n

S. Glazyrin

Turbulence significantly influences the dynamics of flame in SNIa. The large Reynolds number makes impossible the direct numerical simulations of turbulence, and different models of turbulence have to be used. Here we present the simulations with the $k$-$ε$ model. The turbulence is generated by the RTL instability and crucially influences flame front veloci

Timothy Eardley, Jayanta Manoharmayum

We show the inverse deformation problem has an affirmative answer: given a complete local noetherian ring $A$ with finite residue field $\pmb{k}$, we show that there is a topologically finitely generated profinite group $\Gamma$ and an absolutely irreducible continuous representation $\bar\rho:\Gamma\to GL_n(\pmb{k})$ such that $A$ is the universal deformati

H. Chen, H. Kose, Y. Kurtulmaz

A commutative ring $R$ is projective free provided that every finitely generated $R$-module is free. An element in a ring is strongly clean provided that it is the sum of an idempotent and a unit that commutates. Let $R$ be a projective-free ring, and let $h\in R[t]$ be a monic polynomial of degree $n$. We prove, in this article, that every $φ\in M_n(R)$ wit

M. S. Berger

Lorentz and CPT violation can affect the rates for $t$-$\ol t$ production and decay. The Lorentz-violating coefficients in the Standard-Model Extension responsible for modifying the top-quark events have recently been bounded by the D0 Collaboration. To extend the analysis to the LHC the calculations need to be extended to include the gluon fusion production

A. Celi, P. Massignan, J. Ruseckas, N. Goldman

We describe a simple technique for generating a cold-atom lattice pierced by a uniform magnetic field. Our method is to extend a one-dimensional optical lattice into the "dimension" provided by the internal atomic degrees of freedom, yielding a synthetic 2D lattice. Suitable laser-coupling between these internal states leads to a uniform magnetic flu

Marlene Doert, David Paneque

The TeV BL Lac object Markarian 501 has been the subject of a 4.5 month multi-instrument campaign conducted in 2009, which provided an excellent temporal and energy coverage from radio to very high energy gamma rays (>100 GeV, VHE). During the campaign, Mrk 501 was mostly in a comparably low state, but for two flares at VHE with very different characteristic

Yuya Shimoda, Madoka Kawaharada, Kosuke Sato, Takaya Ohashi

The cluster of galaxies MS 1512.4+3647 (z=0.372) was observed with Suzaku for 270 ks. Besides the Fe abundance, the abundances of Mg, Si, S, and Ni are separately determined for the first time in a medium redshift cluster (z>0.3). The derived abundance pattern of MS 1512.4+3647 is consistent with those of nearby clusters, suggesting that the system has simil

Denis Comelli, Fabrizio Nesti, Luigi Pilo

We study the cosmology of general massive gravity theories with five propagating degrees of freedom. This large class of theories includes both the case with a residual Lorentz invariance as the cases with simpler rotational invariance. We find that the existence of a nontrivial homogeneous FRW background, in addition to selecting the lorentz-breaking case,

B. Brun, F. Martins, S. Faniel, B. Hackens

Quantum point contacts exhibit mysterious conductance anomalies in addition to well known conductance plateaus at multiples of 2e^2/h. These 0.7 and zero-bias anomalies have been intensively studied, but their microscopic origin in terms of many-body effects is still highly debated. Here we use the charged tip of a scanning gate microscope to tune in situ th

Emeric Bouin, Vincent Calvez, Grégoire Nadin

In this paper, we study the existence and stability of travelling wave solutions of a kinetic reaction-transport equation. The model describes particles moving according to a velocity-jump process, and proliferating thanks to a reaction term of monostable type. The boundedness of the velocity set appears to be a necessary and sufficient condition for the exi

H. Razmi, N. Fadaei

Using covariant quantization of the electromagnetic field, the Casimir force per unit area experienced by a long conducting cylindrical shell, under both Dirichlet and Neumann boundary conditions, is calculated. The renormalization procedure is based on the plasma cut-off frequency for real conductors. The real case of a gold (silver) cylindrical shell is co

Masato Arai, Yoshishige Kobayashi, Shin Sasaki

We investigate thermal one-loop effective potentials in multi-flavor models with chemical potentials. We study four-dimensional models in which each flavor have different global U(1) charges. Accordingly they have different chemical potentials. We call these "non-uniform chemical potentials," which are organized into a diagonal matrix μ. The mass mat

Thankshila Wimalajeewa, Pramod K. Varshney

We address the problem of joint sparsity pattern recovery based on low dimensional multiple measurement vectors (MMVs) in resource constrained distributed networks. We assume that distributed nodes observe sparse signals which share the same sparsity pattern and each node obtains measurements via a low dimensional linear operator. When the measurements are c

D. G. Green, C. N. Harvey

We show that for collisions of electrons with a high-intensity laser, discrete photon emissions introduce a transverse beam spread which is distinct from that due to classical (or beam shape) effects. Via numerical simulations, we show that this quantum induced transverse momentum gain of the electron is manifest in collisions with a realistic laser pulse of

Cormac Reynolds, Brian Punsly, Christopher O'Dea, Natasha Hurley-Walker

Radio monitoring of the broad absorption line quasar (BALQSO) Mrk 231 from 13.9 GHz to 17.6 GHz detected a strong flat spectrum flare. Even though BALQSOs are typically weak radio sources, the 17.6 GHz flux density doubled in ~150 days, from ~135 mJy to ~270 mJy. It is demonstrated that the elapsed rise time in the quasar rest frame and the relative magnitud

Kyoung Yee Kim, Hyung Won Lee, Yun Soo Myung

We investigate the linearly and quadratically coupled cubic Galileon models that include linear potentials. These models may explain the late-time acceleration. In these cases, we need two equations of state parameter named the native and effective equations of state to test whether the universe is accelerating or not because there is coupling between the co

Lennart Meier

We study vector bundles on the moduli stack of elliptic curves over a local ring R. If R is a field or a discrete valuation ring of (residue) characteristic not 2 or 3, all these vector bundles are sums of line bundles. For R the 3-local integers, we construct higher rank indecomposable vector bundles and give a classification of vector bundles that are iter

G. Carnovale

We show that, for a connected reductive algebraic group G over an algebraically closed field of zero or good characteristic, the parts, called strata, in the partition of G recently introduced by Lusztig are unions of sheets of conjugacy classes. For G simple and adjoint we refine the parametrization of such sheets obtained in previous work with F. Esposito.

Katharine Turner

Persistence diagrams are common objects in the field of Topological Data Analysis. They are topological summaries that capture both topological and geometric structure within data. Recently there has been a surge of interest in developing tools to statistically analyse populations of persistence diagrams, a process hampered by the complicated geometry of the

Volker Diekert, Armin Weiß

The word problem of a finitely generated group is the formal language of words over the generators which are equal to the identity in the group. If this language happens to be context-free, then the group is called context-free. Finitely generated virtually free groups are context-free. In a seminal paper Muller and Schupp showed the converse: A context-free

Adam Doliwa

We present recent developments on geometric theory of the Hirota system and of the non-commutative discrete Kadomtsev-Petviashvili (KP) hierarchy adding also some new results which make the picture more complete. We pay special attention to multidimensional consistency of the Desargues maps and of the resulting non-linear non-commutative systems. In particul

Dorin Popescu, Andrei Zarojanu

Let $I\supsetneq J$ be two squarefree monomial ideals of a polynomial algebra over a field generated in degree $\geq d$, resp. $\geq d+1$ . Suppose that $I$ is generated by three monomials of degrees $d$. If the Stanley depth of $I/J$ is $\leq d+1$ then the usual depth of $I/J$ is $\leq d+1$ too.

Christoph P. Grams, Martin Valldor, Markus Garst, Joachim Hemberger

Competing interactions in the so-called spin-ice compounds stabilize a frustrated ground-state with finite zero-point entropy and, interestingly, emergent magnetic monopole excitations. The properties of these monopoles are at the focus of recent research with particular emphasis on their quantum dynamics. It is predicted that each monopole also possesses an

César Beleño

The following is an overview of the current status of charmless semileptonic B decays and the extraction of the CKM matrix element $|V_{ub}|$ by the Belle and BaBaR collaborations.

Gennadiy Feldman

Let $Ω_p$ be the group of $p$-adic numbers, $ ξ_1$ and $ξ_2$ be independent random variables with values in $Ω_p$ and distributions $μ_1$ and $μ_2$. Let $α_j, β_j$ be topological automorphisms of $Ω_p$. Assuming that the linear forms $L_1=α_1ξ_1 + α_2ξ_2$ and $L_2=β_1ξ_1 + β_2ξ_2$ are independent, we describe possible distributions $μ_1$ and $μ_2$ depending

Paola Cattabriga

By closely rereading the original Turing's 1936 article, we can gain insight about that it is based on the claim to have defined a number which is not computable, arguing that there can be no machine computing the diagonal on the enumeration of the computable sequences. This article provides a careful analysis of Turing's original argument, demonstrating tha

V. Bolpasi, N. K. Efremidis, M. J. Morrissey, P. Condylis

We present a novel, ultra-bright atom-laser and ultra-cold thermal atom beam. Using rf-radiation we strongly couple the magnetic hyperfine levels of 87Rb atoms in a magnetically trapped Bose-Einstein condensate. At low rf-frequencies gravity opens a small hole in the trapping potenital and a well collimated, extremely bright atom laser emerges from just belo

Aurélien Greuet, Mohab Safey El Din

Let $f, f_1, \ldots, f_\nV$ be polynomials with rational coefficients in the indeterminates $\bfX=X_1, \ldots, X_n$ of maximum degree $D$ and $V$ be the set of common complex solutions of $\F=(f_1,\ldots, f_\nV)$. We give an algorithm which, up to some regularity assumptions on $\F$, computes an exact representation of the global infimum $f^\star=\inf_{x\in

Haifeng Xu, Jiuru Zhou

By using Fubini theorem or Tonelli theorem, we find that the zeta function value at 2 is equal to a special integral. Furthermore, We find that this special integral is two times of another special integral. By using this fact we obtain the relationship between Genocchi numbers and Bernoulli numbers. And get some results about Bernoulli polynomials.

J. Martin van Zyl

Least absolute deviation regression is applied using a fixed number of points for all values of the index to estimate the index and scale parameter of the stable distribution using regression methods based on the empirical characteristic function. The recognized fixed number of points estimation procedure uses ten points in the interval zero to one, and leas

Sourav Chakraborty, Rameshwar Pratap, Sasanka Roy, Shubhangi Saraf

Helly's theorem is a fundamental result in discrete geometry, describing the ways in which convex sets intersect with each other. If $S$ is a set of $n$ points in $R^d$, we say that $S$ is $(k,G)$-clusterable if it can be partitioned into $k$ clusters (subsets) such that each cluster can be contained in a translated copy of a geometric object $G$. In thi

S. A. Levshakov, C. Henkel, D. Reimers, P. Molaro

We report on new tests that improve our previous (2009-2010) estimates of the electron-to-proton mass ratio variation, mu = m_e/m_p. Subsequent observations (2011-2013) at the Effelsberg 100-m telescope of a sample of eight molecular cores from the Milky Way disk reveal systematic errors in the measured sky frequencies varying with an amplitude +/-0.01 km/s