July 2009 arXiv papers — page 2

E. I. Bunina

In the paper we prove that every automorphism of a Chevalley group of type $F_4$ over a commutative local ring with~1/2 is standard, i. e., it is a composition of ring and inner automorphisms.

J. Cerrillo, A. Retzker, M. B. Plenio

We present a robust and fast laser cooling scheme suitable for trapped atoms and ions. Based on quantum interference, generated by a special laser configuration, it is able to rapidly cool the system such that the final phonon occupation vanishes to zeroth order in the Lamb-Dicke parameter in contrast to existing cooling schemes. Furthermore, it is robust un

Eric Perim, Douglas S. Galvao

Carbon nanoscrolls (CNSs) are structures formed by rolling up graphene layers into a papyruslike shape. CNNs have been experimentally produced by different groups. Boron nitride nanoscrolls (BNNSs) are similar structures using boron nitride instead of graphene layers. In this work we report molecular mechanics and molecular dynamics results for the structura

Viorel Iftimie, Marius Mantoiu, Radu Purice

We show coincidence of the two definitions of the integrated density of states (IDS) for a class of relativistic Schroedinger operators with magnetic fields and scalar potentials, the first one relying on the eigenvalue counting function of operators induced on open bounded sets with Dirichlet boundary conditions, the other one involving the spectral project

S. R. Clark, J. Prior, M. J. Hartmann, D. Jaksch

In recent work Hartmann et al [Phys. Rev. Lett. 102, 057202 (2009)] demonstrated that the classical simulation of the dynamics of open 1D quantum systems with matrix product algorithms can often be dramatically improved by performing time evolution in the Heisenberg picture. For a closed system this was exemplified by an exact matrix product operator solutio

I. N. Pashchenko, B. V. Komberg

Using standard cosmological model we show that the cores of ultra-compact radio sources observed with ground-based Very Long Baseline Interferometry (VLBI) on the angular scales of milliarcseconds cannot be used as a reasonable standard unit of linear size. "Luminosity - linear size" correlation obtained by many authors for ultra compact radio source

Andrew D. Warshall

We introduce the concepts of a pair of valuations and a good generating set and show how they can be used to prove geometric properties of soluble groups.

David S. Herscovici, Benjamin D. Hester, Glenn H. Hurlbert

We prove a generalization of Graham's Conjecture for optimal pebbling with arbitrary sets of target distributions. We provide bounds on optimal pebbling numbers of products of complete graphs and explicitly find optimal $t$-pebbling numbers for specific such products. We obtain bounds on optimal pebbling numbers of powers of the cycle $C_5$. Finally, we

Jonathan Henry Brown

In 1990, Rieffel defined a notion of proper action of a group $H$ on a $C^*$-algebra $A$. He then defined a generalized fixed point algebra $A^α$ for this action and showed that $A^α$ is Morita equivalent to an ideal of the reduced crossed product. We generalize Rieffel's notion to define proper groupoid dynamical systems and show that the generalized fi

O. Buchmueller, R. Cavanaugh, A. De Roeck, J. R. Ellis

On the basis of frequentist analyses of experimental constraints from electroweak precision data, g-2, B physics and cosmological data, we investigate the parameters of the constrained MSSM (CMSSM) with universal soft supersymmetry-breaking mass parameters, and a model with common non-universal Higgs masses (NUHM1). We present chi^2 likelihood functions for

Benjamin C. Bromley, Scott J. Kenyon, Warren R. Brown, Margaret J. Geller

Runaway stars ejected from the Galactic disk populate the halo of the Milky Way. To predict the spatial and kinematic properties of runaways, we inject stars into a Galactic potential, compute their trajectories through the Galaxy, and derive simulated catalogs for comparison with observations. Runaways have a flattened spatial distribution, with higher velo

T. Frederico, E. Pace, B. Pasquini, G. Salmé

We investigate the model dependence of no-helicity flip generalized parton distribution of the pion upon different approaches for the quark-hadron and quark-photon vertexes, in the spacelike region. In order to obtain information on contributions from both the valence and non-valence regions, we compare results for spacelike momentum transfers obtained from

G. Gentili, C. Stoppato

A new class of regular quaternionic functions, defined by power series in a natural fashion, has been introduced in recent years. Several results of the theory recall the classical complex analysis, whereas other results reflect the peculiarity of the quaternionic structure. A more recent paper identified a larger class of domains, on which the study of regu

M. Syafwan, H. Susanto, S. M. Cox

We consider a parametrically driven Klein--Gordon system describing micro- and nano-devices, with integrated electrical and mechanical functionality. Using a multiscale expansion method we reduce the system to a discrete nonlinear Schrodinger equation. Analytical and numerical calculations are performed to determine the existence and stability of fundamental

G. Carminati, M. Bazzotti, S. Biagi, S. Cecchini

Neutrino telescopes are opening new opportunities in observational high energy astrophysics. In these detectors, atmospheric muons from primary cosmic ray interactions in the atmosphere play an important role. They provide the most abundant source of events for calibration and for testing the reconstruction algorithms. On the other hand, they represent the m

Patrick Joly, Ricardo Weder

We study the propagation of acoustic waves in a fluid that is contained in a thin two-dimensional tube, and that it is moving with a velocity profile that only depends on the transversal coordinate of the tube. The governing equations are the Galbrun equations, or, equivalently, the linearized Euler equations. We analyze the approximate model that was recent

Giovanni Coppola

We deeply appreciate the papers of Ivić on the links between the $2k-$th moments of the Riemann zeta function and, say, $d_k$, the $k-$divisor function. More specifically, both the one bounding the $2k-$th moment with a simple average of correlations of the $d_k$ (Palanga 1996 Conference Proceedings) and the more recent (arXiv:0708.1601v2 to appear on JTNB),

Vadim V. Shurygin

In the present paper, we study complete and vertical lifts of tensor fields from a smooth manifold $M$ to its Weil bundle $T^A M$ defined by a Frobenius Weil algebra $A$. For a Poisson manifold $(M,w)$, we show that the complete lift $w^C$ and the vertical lift $w^V$ of the Poisson tensor $w$ are Poisson tensors on $T^A M$ and establish their properties. We

Riccardo Fantoni, Achille Giacometti, Alexandr Malijevský, Andrés Santos

We study structural and thermophysical properties of a one-dimensional classical fluid made of penetrable spheres interacting via an attractive square-well potential. Penetrability of the spheres is enforced by reducing from infinite to finite the repulsive energy barrier in the pair potentials As a consequence, an exact analytical solution is lacking even i

Yin Lu, Christian Miniatura, Berthold-Georg Englert

The transmission through a stack of identical slabs that are separated by gaps with random widths is usually treated by calculating the average of the logarithm of the transmission probability. We show how to calculate the average of the transmission probability itself with the aid of a recurrence relation and derive analytical upper and lower bounds. The up

Brian C. Rushton

The study of geometric group theory has suggested several theorems related to subdivision tilings that have a natural hyperbolic structure. However, few examples exist. We construct subdivision tilings for the complement of every nonsingular, prime alternating link. These tilings define a combinatorial space at infinity, similar to the space at infinity for

Ayla Gafni

This note examines a problem in enumerative and asymptotic combinatorics involving the classical structure of integer compositions. What is sought is an analysis on average and in distribution of the length of the longest run of consecutive equal parts in a composition of size n. The problem was recently posed by Herbert Wilf (see arXiv: 0906.5196).

R. Alicandro, M. Cicalese, M. Ponsiglione

We introduce and discuss discrete two-dimensional models for XY spin systems and screw dislocations in crystals. We prove that, as the lattice spacing $\e$ tends to zero, the relevant energies in these models behave like a free energy in the complex Ginzburg-Landau theory of superconductivity, justifying in a rigorous mathematical language the analogies betw

Q. J. Zheng, Y. He, T. Wu, G. Wu

We systematically studied the transport properties of single crystals of $Eu_{1-x}Sr_xFe_{2-y}$Co$_{y}As_2$. Co doping can suppress the spin-density wave (SDW) ordering and induces a superconducting transition, but a resistivity reentrance due to the antiferromagnetic ordering of $Eu^{2+}$ spins is observed, indicating the competition between antiferromagnet

Cesar R. de Oliveira, Mariza S. Simsen

Let $U_F$ be the Floquet operator of a time periodic hamiltonian $H(t)$. For each positive and discrete observable $A$ (which we call a {\em probe energy}), we derive a formula for the Laplace time average of its expectation value up to time $T$ in terms of its eigenvalues and Green functions at the circle of radius $e^{1/T}$. Some simple applications are pr

J. J. Rodriguez-Vega, W. A. Zuniga-Galindo

We study the solutions of equations of type $f(D,α)u=v$, where $f(D,α)$ is a $p$-adic pseudo-differential operator. If $v$ is a Bruhat-Schwartz function, then there exists a distribution $E_α$, a fundamental solution, such that $u=E_α\ast v$ is a solution. However, it is unknown to which function space $E_α\ast v$ belongs. In this paper, we show that if $f(D

F. Massee, S. de Jong, Y. Huang, J. Kaas

We elucidate the termination surface of cleaved single crystals of the BaFe_(2-x)Co_(x)As_(2) and Fe_(y)Se_(1-x)Te_(x) families of the high temperature iron based superconductors. By combining scanning tunneling microscopic data with low energy electron diffraction we prove that the termination layer of the Ba122 systems is a remnant of the Ba layer, which e

P. Roig

We study two and three meson decays of the tau lepton within the framework of the Resonance Chiral Theory, that is based on the following properties of QCD: its chiral symmetry in the massless case, its large-N_C limit, and the asymptotic behaviour it demands to the relevant form factors. Most of the couplings in the Lagrangian are determined this way render

Leah B. Shaw, Ira B. Schwartz

We study vaccine control for disease spread on an adaptive network modeling disease avoidance behavior. Control is implemented by adding Poisson distributed vaccination of susceptibles. We show that vaccine control is much more effective in adaptive networks than in static networks due to an interaction between the adaptive network rewiring and the vaccine a

Francesco Carraro, Sergio Fonte, Diego Turrini, Maria Cristina De Sanctis

Planetary sciences can benefit from several different sources of information, i.e. ground-based or near Earth-based observations, space missions and laboratory experiments. The data collected from these sources, however, are spread over a number of smaller, separate communities and stored through different facilities: this makes it difficult to integrate the

Roland Diehl

Gamma-ray telescopes are capable of measuring radioactive trace isotopes from cosmic nucleosynthesis events. Such measurements address new isotope production rather directly for a few key isotopes such as 44Ti, 26Al, 60Fe, and 56Ni, as well as positrons from the beta^+-decay variety. Experiments of the past decades have now established an astronomy with gamm

C. Trachternach, W. J. G. de Blok, S. S. McGaugh, J. M. van der Hulst

The baryonic Tully-Fisher relation (BTF) is a fundamental relation between baryonic mass and maximum rotation velocity. It can be used to estimate distances, as well as to constrain the properties of dark matter and its relation with the visible matter. In this paper, we explore if extremely low-mass dwarf galaxies follow the same BTF relation as high-mass g

Erika Cerasti, Alessandro Treves

In the mammalian hippocampus, the dentate gyrus (DG) is characterized by sparse and powerful unidirectional projections to CA3 pyramidal cells, the so-called mossy fibers. Mossy fiber synapses appear to duplicate, in terms of the information they convey, what CA3 cells already receive from entorhinal cortex layer II cells, which project both to the dentate g

V. H. Tran, R. T. Khan, P. Wisniewski, E. Bauer

We report a novel pressure-induced spin-density-wave transition in the superconductor Mo3Sb7 figured our by measurements of the electrical resistivity and magnetization under hydrostatic pressure. The critical temperature of superconducting Mo3Sb7 is found to increase with increasing pressure, from 2.15 K at 0.2 kbar up to 2.37 K at 22 kbar. Above 4.5 kbar,

Johan Fastenakels, Marian Ioan Munteanu, Joeri Van der Veken

In this article we generalize the notion of constant angle surfaces in S^2 x R and H^2 x R to general Bianchi-Cartan-Vranceanu spaces, i.e. essentially to three-dimensional homogeneous spaces with a four-dimensional isometry group. We show that these surfaces have constant Gaussian curvature and we give a complete local classification in the Heisenberg group

R. Rossi, K. M. Fonseca, Romero M. C. Nemes

The usual semiclassical approximation for atom-field dynamics consists in substituting the field operators by complex numbers related to the (supposedly large enough) intensity of the field. We show that a semiclassical evolution for coupled systems can always be obtained by frequent Zeno-like measurements on the state of one subsystems, independently of the

Cyril Imbert, Panagiotis E. Souganidis

This paper is concerned with diffusion-reaction equations where the classical diffusion term, such as the Laplacian operator, is replaced with a singular integral term, such as the fractional Laplacian operator. As far as the reaction term is concerned, we consider bistable non-linearities. After properly rescaling (in time and space) these integro-different

Jiangbo Zhou, Lixin Tian

In this Letter, by using the bifurcation method of dynamical systems, we obtain the analytic expressions of soliton solution of the osmosis K(2, 2) equation.

Mário Ziman, Tomáš Rybár

We analyze the depth of the memory of quantum memory channels generated by a fixed unitary transformation describing the interaction between the principal system and internal degrees of freedom of the process device. We investigate the simplest case of a qubit memory channel with a two-level memory system. In particular, we explicitly characterize all intera

Qian-Qian Shi, Sheng-Hao Li, Jian-Hui Zhao, Huan-Qiang Zhou

An algorithm to find a graded Projected Entangled-Pair State representation of the ground state wave functions is developed for translationally invariant strongly correlated electronic systems on infinite-size lattices in two spatial dimensions. It is tested for the two-dimensional t-J model at and away from half filling, with truncation dimensions up to 6.

Remo Ruffini, Alexey G. Aksenov, Maria Grazia Bernardini, Carlo Luciano Bianco

(Shortened) [...] After recalling the basic features of the "fireshell model", we emphasize the following novel results: 1) the interpretation of the X-ray flares in GRB afterglows as due to the interaction of the optically thin fireshell with isolated clouds in the CircumBurst Medium (CBM); 2) an interpretation as "fake - disguised" short GR

R. Brustein, G. Dvali, G. Veneziano

We show that the existence of semiclassical black holes of size as small as a minimal length scale $l_{UV}$ implies a bound on a gravitational analogue of 't-Hooft's coupling $λ_G(l)\equiv N(l) G_N/l^2$ at all scales $l \ge l_{UV}$. The proof is valid for any metric theory of gravity that consistently extends Einstein's gravity and is based on tw

T. Bulik, K. Belczynski

We review the formation scenarios for binary black holes, and show that their coalescence rate depends very strongly on the outcome of the second mass transfer. However, the observations of IC10 X-1, an binary with a massive black hole accreting from a Wolf-Rayet star proves that this mass transfer can be stable. We analyze the future evolution of IC10 X-1 a

Philipp Biallass, Thomas Hebbeker

The cosmic muon generator CMSCGEN is based on a parametrization of the differential muon flux at ground level, as obtained from the air shower simulation program CORSIKA. We present the underlying ansatz for this parameterization and provide an approximation of the momentum and angular distributions in terms of simple polynomials, in the momentum range 3 to

D. Makogon, A. Alamir, C. Morais Smith

This work treats the effects of disorder and interactions in a quantum Hall ferromagnet, which is realized in a two-dimensional electron gas (2DEG) in a perpendicular magnetic field at Landau level filling factor equal one. We study the problem by projecting the original fermionic Hamiltonian into magnon states, which behave as bosons in the vicinity of the

Johannes Aastrup, Jesper M. Grimstrup, Mario Paschke, Ryszard Nest

We construct normalizable, semi-classical states for the previously proposed model of quantum gravity which is formulated as a spectral triple over holonomy loops. The semi-classical limit of the spectral triple gives the Dirac Hamiltonian in 3+1 dimensions. Also, time-independent lapse and shift fields emerge from the semi-classical states. Our analysis sho

Marco Leonetti, Riccardo Sapienza, Marta Ibisate, Claudio Conti

We present a detailed study of the gain length in an active medium obtained by doping of DNA strands with DCM dye molecules. The superior thermal stability of the composite and its low quenching, permits to obtain optical gain coefficient larger than 300 cm^-1. We also show that such an active material is excellent for integration into photonic nano-structur

Jiangbo Zhou, Lixin Tian

In this paper, we study an initial boundary value problem for a generalized Camassa-Holm equation. We establish local well-posedness of this closed-loop system by using Kato theorem for abstract quasilinear evolution equation of hyperbolic type. Then, by using multiplier technique, we obtain a conservation law which enable us to present a blow-up result.

Henry H. Hsieh

The mysterious solar system object 133P/(7968) Elst-Pizarro is dynamically asteroidal, yet displays recurrent comet-like dust emission. Two scenarios were hypothesized to explain this unusual behavior: (1) 133P is a classical comet from the outer solar system that has evolved onto a main-belt orbit, or (2) 133P is a dynamically ordinary main-belt asteroid on

Raphaël Cerf, Marie Théret

We consider the standard first passage percolation model in the rescaled graph $\mathbb{Z}^d/n$ for $d\geq 2$, and a domain $Ω$ of boundary $Γ$ in $\mathbb{R}^d$. Let $Γ^1$ and $Γ^2$ be two disjoint open subsets of $Γ$, representing the parts of $Γ$ through which some water can enter and escape from $Ω$. We investigate the asymptotic behaviour of the flow $ϕ

G. Dell'Antonio, R. Figari, A. Teta

We consider a simple model of a cloud chamber consisting of a test particle (the alpha-particle) interacting with two other particles (the atoms of the vapour) subject to attractive potentials centered in $a_1, a_2 \in \mathbb{R}^3$. At time zero the alpha-particle is described by an outgoing spherical wave centered in the origin and the atoms are in their g

E. Comay

Physical consequences are derived from the following mathematical structures: the variational principle, Wigner's classifications of the irreducible representations of the Poincare group and the duality invariance of the homogeneous Maxwell equations. The analysis is carried out within the validity domain of special relativity. Hierarchical relations bet

Raphaël Cerf, Marie Théret

We consider the standard first passage percolation model in the rescaled graph $\mathbb{Z}^d/n$ for $d\geq 2$, and a domain $Ω$ of boundary $Γ$ in $\mathbb{R}^d$. Let $Γ^1$ and $Γ^2$ be two disjoint open subsets of $Γ$, representing the parts of $Γ$ through which some water can enter and escape from $Ω$. We investigate the asymptotic behaviour of the flow $ϕ

Nanying Liang, Laurent Bougrain

EEG-BCIs have been well studied in the past decades and implemented into several famous applications, like P300 speller and wheelchair controller. However, these interfaces are indirect due to low spatial resolution of EEG. Recently, direct ECoG-BCIs attract intensive attention because ECoG provides a higher spatial resolution and signal quality. This makes

C. Faugeras, M. Amado, P. Kossacki, M. Orlita

Magneto Raman scattering study of the E$_{2g}$ optical phonons in multi-layer epitaxial graphene grown on a carbon face of SiC are presented. At 4.2K in magnetic field up to 33 T, we observe a series of well pronounced avoided crossings each time the optically active inter Landau level transition is tuned in resonance with the E$_{2g}$ phonon excitation (at

H. Zhang, D. Y. Tang, L. M. Zhao, X. Wu

We report on the experimental observation of two types of phase-locked vector soliton in weakly birefringent cavity erbium-doped fiber lasers. While a phase-locked dark-dark vector soliton was only observed in fiber lasers of positive dispersion, a phase-locked dark-bright vector soliton was obtained in fiber lasers of either positive or negative dispersion.

Arnaud Durand, Neil Jones, Johann Makowsky, Malika More

In 1952, Heinrich Scholz published a question in the Journal of Symbolic Logic asking for a characterization of spectra, i.e., sets of natural numbers that are the cardinalities of finite models of first order sentences. Günter Asser asked whether the complement of a spectrum is always a spectrum. These innocent questions turned out to be seminal for the dev

Sebastien Bubeck, Marina Meila, Ulrike von Luxburg

We investigate the role of the initialization for the stability of the k-means clustering algorithm. As opposed to other papers, we consider the actual k-means algorithm and do not ignore its property of getting stuck in local optima. We are interested in the actual clustering, not only in the costs of the solution. We analyze when different initializations

E. Y. Shchekinova

We report the synchronization behavior in a one-dimensional chain of identical limit cycle oscillators coupled to a mass-spring load via a force relation. We consider the effect of periodic parametric modulation on the final synchronization states of the system. Two types of external parametric excitations are investigated numerically: periodic modulation of

Vicente Cortés, Lars Schäfer

Let L\subset V=\bR^{k,l} be a maximally isotropic subspace. It is shown that any simply connected Lie group with a bi-invariant flat pseudo-Riemannian metric of signature (k,l) is 2-step nilpotent and is defined by an element η\in Λ^3L\subset Λ^3V. If ηis of type (3,0)+(0,3) with respect to a skew-symmetric endomorphism J with J^2=\e Id, then the Lie group {

D. Shaltiel, H-A. Krug von Nidda, B. Rosenstein, B. Ya. Shapiro

A memory effect in the Josephson vortex system created by magnetic field in the highly anisotropic superconductors Bi2212 and Bi2223 is demonstrated using microwave power absorption. This surprising effect appears despite a very low viscosity of Josephson vortices compared to Abrikosov vortices. The superconductor is field cooled in DC magnetic field H_{m} o

Johannes Huebschmann

Using the language and terminology of relative homological algebra, in particular that of derived functors, we introduce equivariant cohomology over a general Lie-Rinehart algebra and equivariant de Rham cohomology over a locally trivial Lie groupoid in terms of suitably defined monads (also known as triples) and the associated standard constructions. This e

Yong Gao

We prove that the treewidth of an Erdös-Rényi random graph $\rg{n, m}$ is, with high probability, greater than $βn$ for some constant $β> 0$ if the edge/vertex ratio $\frac{m}{n}$ is greater than 1.073. Our lower bound $\frac{m}{n} > 1.073$ improves the only previously-known lower bound. We also study the treewidth of random graphs under two other random mod

G. Ros, A. D. Supanitsky, G. A. Medina-Tanco, L. del Peral

A new family of parameters intended for composition studies is presented. They make exclusive use of surface data combining the information from the total signal at each triggered detector and the array geometry. We perform an analytical study of these composition estimators in order to assess their reliability, stability and possible optimization. The influ

S. N. Pandey, P. S. Bindu, M. Senthilvelan, M. Lakshmanan

In this second of the set of two papers on Lie symmetry analysis of a class of Liénard type equation of the form $\ddot {x} + f(x)\dot {x} + g(x)= 0$, where over dot denotes differentiation with respect to time and $f(x)$ and $g(x)$ are smooth functions of their variables, we isolate the equations which possess maximal Lie point symmetries. It is well known

S. N. Pandey, P. S. Bindu, M. Senthilvelan, M. Lakshmanan

We carry out a detailed Lie point symmetry group classification of the Liénard type equation, $\ddot{x}+f(x)\dot{x}+g(x) = 0$, where $f(x)$ and $g(x)$ are arbitrary smooth functions of $x$. We divide our analysis into two parts. In the present first part we isolate equations that admit lesser parameter Lie point symmetries, namely, one, two and three paramet

David Eppstein, Kevin A. Wortman

Let G be a graph that may be drawn in the plane in such a way that all internal faces are centrally symmetric convex polygons. We show how to find a drawing of this type that maximizes the angular resolution of the drawing, the minimum angle between any two incident edges, in polynomial time, by reducing the problem to one of finding parametric shortest path

Chuan-Tsung Chan, Wei-Ming Chen

The operator formalism of the first quantized string theory is applied to the stringy excitations in the linear dilaton background. In particular, the normal-ordered vertex operators in the old-covariant spectrum of the bosonic open string, which correspond to the physical state solutions of the Virasoro constraints, are shown to satisfy the conformal algebr

Maria R. Drout, Philip Massey, Georges Meynet, Susan Tokarz

The yellow supergiant content of nearby galaxies can provide a critical test of stellar evolution theory, bridging the gap between the hot, massive stars and the cool red supergiants. But, this region of the color-magnitude diagram is dominated by foreground contamination, requiring membership to somehow be determined. Fortunately, the large negative systemi

Pierre Lescanne

An abstraction of normal form games is proposed, called Feasibility/Desirability Games (or FD Games in short). FD Games can be seen from three points of view: as a new presentation of games in which Nash equilibria can be found, as choice models in microeconomics or as a model of evolution in games.

Michel Benaim, Olivier Raimond

Self-interacting diffusions are processes living on a compact Riemannian manifold defined by a stochastic differential equation with a drift term depending on the past empirical measure of the process. The asymptotics of this measure is governed by a deterministic dynamical system and under certain conditions it converges almost surely towards a deterministi

Ebrahim A. Gharavol, Ying-Chang Liang, Koenraad Mouthaan

This paper studies the problem of robust downlink beamforming design in a multiuser Multi-Input Single-Output (MISO) Cognitive Radio Network (CR-Net) in which multiple Primary Users (PUs) coexist with multiple Secondary Users (SUs). Unlike conventional designs in CR-Nets, in this paper it is assumed that the Channel State Information (CSI) for all relevant c

Lei Huang, Siming Liu, Zhi-Qiang Shen, Ye-Fei Yuan

We explore the parameter space of the two temperature pseudo-Newtonian Keplerian accretion flow model for the millimeter and shorter wavelength emission from Sagittarius A*. A general relativistic ray-tracing code is used to treat the radiative transfer of polarized synchrotron emission from the flow. The synchrotron self-Comptonization and bremsstrahlung em

Benjamin Brau, Christopher May, Robert Ormond, John Essick

An instructional laboratory experiment to measure the muon mass is described. Using coincidence-anticoincidence detection, the decay of a cosmic-ray muon into an electron (or positron) is observed in a multiplate spark chamber, and recorded with a triggered CCD detector. The energy of the charged decay-product particle is then quantified by counting the numb

Yixuan Li, Gregory D. Fleishman

The Letter takes up a question of what radio emission is produced by electrons at the very acceleration site of a solar flare. Specifically, we calculate incoherent radio emission produced within two competing acceleration models--stochastic acceleration by cascading MHD turbulence and regular acceleration in collapsing magnetic traps. Our analysis clearly d

L. Guzzo, P. Schuecker, H. Boehringer, C. A. Collins

We present the final data from the spectroscopic survey of the ROSAT-ESO Flux-Limited X-ray (REFLEX) catalog of galaxy clusters. The REFLEX survey covers 4.24 steradians (34% of the entire sky) below a declination of 2.5 deg and at high Galactic latitude (|b| > 20 deg). The REFLEX catalog includes 447 entries with a median redshift of 0.08 and is better than

Y. Ishida, T. Baba, R. Eguchi, M. Matsunami

Soft-x-ray photoemission and absorption spectroscopies are employed to investigate the electronic structures of Sr_{1-x}Rh_{2}O_{4}. Similarly to the layered cobaltates such as Na_{1-x}CoO_{2}, a valence-band satellite feature (VBS) occurs at higher binding energy to the O 2p band. We find that the VBS resonates at the O 1s edge. Additionally, core absorptio

Shuanhu Qi, Xinghu Zhang, Dadong Yan

The formation of interface from an initial sharp interface in polydisperse A/B blends is studied using the external potential dynamic method. The present model is a nonlocal coupling model as we take into account the correlation between segments in a single chain. The correlation is approximately expressed by Debye function and the diffusion dynamics are bas

Alexander Khitun, Mingqiang Bao, Kang L. Wang

We describe and analyze a cellular nonlinear network based on magnetic nanostructures for image processing. The network consists of magneto-electric cells integrated onto a common ferromagnetic film - spin wave bus. The magneto-electric cell is an artificial two-phase multiferroic structure comprising piezoelectric and ferromagnetic materials. A bit of infor

Shuanhu Qi, Shuang Yang, Dadong Yan

Based on a modified expression of the rate of the convective constraint release, we present a new contour-variable model of constitutive equations in which the non-uniform segmental stretch and the non-Gaussian chain statistical treatment of the single chain are considered to describe the polymer chain dynamics and the rheological behavior of an entangled sy

Ivan I. Naumov, Zhiyong Li, Alexander M. Bratkovsky

New type of plasmonic nanoparticles - silver octopods that can be synthesized with a variety of shapes - have been demonstrated to show versatile optical response using the discrete dipole approximation. The octopods show a complex behavior at optical (visible, IR) wavelengths, with three major resonances that can be tuned up to a desired response that makes

Raymond Molzon, Iosif Pinelis

Pearson's is the most common correlation statistic, used mainly in parametric settings. Most common among nonparametric correlation statistics are Spearman's and Kendall's. We show that for bivariate normal i.i.d. samples the pairwise asymptotic relative efficiency between these three statistics depends monotonically on the population correlation

Nima Arkani-Hamed, Freddy Cachazo, Clifford Cheung, Jared Kaplan

We propose a dual formulation for the S Matrix of N = 4 SYM. The dual provides a basis for the "leading singularities" of scattering amplitudes to all orders in perturbation theory, which are sharply defined, IR safe data that uniquely determine the full amplitudes at tree level and 1-loop, and are conjectured to do so at all loop orders. The scatter

Pranav Agrawal, Joy Kuri

Many basic key distribution schemes specifically tuned to wireless sensor networks have been proposed in the literature. Recently, several researchers have proposed schemes in which they have used group-based deployment models and assumed predeployment knowledge of the expected locations of nodes. They have shown that these schemes achieve better performance

Yacine Mehtar-Tani, Georg Wolschin

We investigate baryon transport in relativistic heavy-ion collisions at energies reached at the CERN Super Proton Synchrotron, BNL Relativistic Heavy-Ion Collider (RHIC), and CERN LHC in the model of saturation. An analytical scaling law is derived within the color glass condensate framework based on small-coupling QCD. Transverse momentum spectra, net-baryo

Amanda Weinstein

The Cygnus region of the Galactic plane contains many known supernova remnants, pulsars, X-ray and GeV gamma-ray emitters which make it a prime candidate for a Very High Energy (VHE) gamma-ray survey in the Northern Hemisphere. The VERITAS observatory, an array of four atmospheric Cherenkov telescopes located at the base of Mt. Hopkins in southern Arizona, U

Alina Bucur, Chantal David, Brooke Feigon, Matilde Lalín

We study the variation of the trace of the Frobenius endomorphism associated to a cyclic trigonal curve of genus g over a field of q elements as the curve varies in an irreducible component of the moduli space. We show that for q fixed and g increasing, the limiting distribution of the trace of the Frobenius equals the sum of q+1 independent random variables

Tao Hong, R. Custelcean, B. C. Sales, B. Roessli

A novel organometallic compound 2Dioxane.CuCl2.2H2O has been synthesized and structurally characterized by X-ray crystallography. Magnetic susceptibility and zero-field inelastic neutron scattering have also been used to study its magnetic properties. It turns out that this material is a weakly coupled one-dimensional S=1/2 Heisenberg antiferromagnetic chain

Gregory Gutin, Eun Jung Kim, Matthias Mnich, Anders Yeo

We study ordinal embedding relaxations in the realm of parameterized complexity. We prove the existence of a quadratic kernel for the {\sc Betweenness} problem parameterized above its tight lower bound, which is stated as follows. For a set $V$ of variables and set $\mathcal C$ of constraints "$v_i$ \mbox{is between} $v_j$ \mbox{and} $v_k$", decide w

A. D. Guclu, P. Potasz, O. Voznyy, M. Korkusinski

When an electron is confined to a triangular atomic thick layer of graphene [1-5] with zig-zag edges, its energy spectrum collapses to a shell of degenerate states at the Fermi level (Dirac point) [6-9]. The degeneracy is proportional to the edge size and can be made macroscopic. This opens up the possibility to design a strongly correlated electronic system

Eitan Altman, Francesco De Pellegrini, Lucile Sassatelli

Delay tolerant Networks (DTNs) leverage the mobility of relay nodes to compensate for lack of permanent connectivity and thus enable communication between nodes that are out of range of each other. To decrease message delivery delay, the information to be transmitted is replicated in the network. We study replication mechanisms that include Reed-Solomon type

Jo Bovy, David W. Hogg, Hans-Walter Rix

Masers found in massive star-forming regions can be located precisely in six-dimensional phase space and therefore serve as a tool for studying Milky Way dynamics. The non-random orbital phases at which the masers are found and the sparseness of current samples require modeling. Here we model the phase-space distribution function of 18 precisely measured Gal

L. Pozzetti, M. Bolzonella, E. Zucca, G. Zamorani

We present the Galaxy Stellar Mass Function (MF) up to z~1 from the zCOSMOS-bright 10k spectroscopic sample. We investigate the total MF and the contribution of ETGs and LTGs, defined by different criteria (SED, morphology or star formation). We unveil a galaxy bimodality in the global MF, better represented by 2 Schechter functions dominated by ETGs and LTG

Daniel Baumann

In a series of five lectures I review inflationary cosmology. I begin with a description of the initial conditions problems of the Friedmann-Robertson-Walker (FRW) cosmology and then explain how inflation, an early period of accelerated expansion, solves these problems. Next, I describe how inflation transforms microscopic quantum fluctuations into macroscop

Ian Low, Riccardo Rattazzi, Alessandro Vichi

We derive constraints on the sign of couplings in an effective Higgs Lagrangian using prime principles such as the naturalness principle, global symmetries, and unitarity. Specifically, we study four dimension-six operators, O_H, O_y, O_g, and O_gamma, which contribute to the production and decay of the Higgs boson at the Large Hadron Collider (LHC), among o

Rowan Killip, Soonsik Kwon, Shuanglin Shao, Monica Visan

We consider the mass-critical generalized Korteweg--de Vries equation $$(\partial_t + \partial_{xxx})u=\pm \partial_x(u^5)$$ for real-valued functions $u(t,x)$. We prove that if the global well-posedness and scattering conjecture for this equation failed, then, conditional on a positive answer to the global well-posedness and scattering conjecture for the ma

O. V. Gamayun, E. V. Gorbar, V. P. Gusynin

It is well known that there are resonant states with complex energy for the supercritical Coulomb impurity in graphene. We show that opening of a quasiparticle gap decreases the imaginary part of energy, |ImE|, of these states and stabilizes the system. For gapless quasiparticles with strong Coulomb interaction in graphene, we solve the Bethe-Salpeter equati

S. James Gates, Gabriele Tartaglino-Mazzucchelli

Building on a previous derivation of the local chiral projector for a two dimensional superspace with eight real supercharges, we provide the complete density projection formula required for locally supersymmetrical theories in this context. The derivation of this result is shown to be very efficient using techniques based on the Ectoplasmic construction of

Lars Hofer, Ulrich Nierste, Dominik Scherer

We study the Minimal Supersymmetric Standard Model with Minimal Flavour Violation for the case of a large parameter tanbeta and arbitrary values of the supersymmetric mass parameters. We derive several resummation formulae for tanbeta-enhanced loop corrections, which were previously only known in the limit of supersymmetric masses far above the electroweak s

Tameem Albash, Clifford V. Johnson

We study the effects of an external magnetic field on the properties of the quasiparticle spectrum of the class of 2+1 dimensional strongly coupled theories holographically dual to charged AdS$_4$ black holes at zero temperature. We uncover several interesting features. At certain values of the magnetic field, there are multiple quasiparticle peaks represent