October 2008 arXiv papers — page 3

Shardha Jogee

Hierarchical Lambda CDM models provide a successful paradigm for the growth of dark matter on large scales, but they face important challenges in predicting how the baryonic components of galaxies evolve. I present constraints on two aspects of this evolution: (1) The interaction history of galaxies over the last 7 Gyr and the impact of interactions on their

Akio K. Inoue, Hideyuki Kamaya

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $Γ_{\rm pe} = 1.2\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\cal D}/10^{-4})(n_{\rm H}/10^{-5} {\rm cm^{-3}})^{4/3} (J_{\rm L}/10^{-21} {\rm erg s^{-1} cm^{-2} Hz^{-1} sr^{-1}})^{2/3} (T/10^4 {\rm K})^{-

G. Ambika, R. E. Amritkar

A method to synchronize two chaotic systems with anticipation or lag, coupled in the drive response mode, is proposed. The coupling involves variable delay with three time scales. The method has the advantage that synchronization is realized with intermittant information about the driving system at intervals fixed by a reset time. The stability of the synchr

S. Denisov, P. Hanggi, J. L. Mateos

We consider a primary model of ac-driven Brownian motors, i.e., a classical particle placed in a spatial-time periodic potential and coupled to a heat bath. The effects of fluctuations and dissipations are studied by a time-dependent Fokker-Planck equation. The approach allows us to map the original stochastic problem onto a system of ordinary linear algebra

BES Collaboration

By analyzing the data sets of 17.3, 6.5 and 1.0 pb$^{-1}$ taken, respectively, at $\sqrt s= 3.773$, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for $e^+e^-\to π^+π^-π^0π^0$, $K^+K^-π^0π^0$, $2(π^+π^-π^0)$, $K^+K^-π^+π^-π^0π^0$ and $3(π^+π^-)π^0π^0$ at the three energy points. Based on these cross

BES Collaboration

By analyzing the data sets of 17.3 pb$^{-1}$ taken at $\sqrt s= 3.773$ GeV and of 6.5 pb$^{-1}$ taken at $\sqrt s= 3.650$ GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for the exclusive light hadron final states of $K_S^0K^-π^+$, $K_S^0K^-π^+π^0$, $K_S^0K^-π^+π^+π^-$, $K_S^0K^-π^+π^+π^-π^0$, $K_S^0K^-π^+π^+π^+π^-π^

Hanindyo Kuncarayakti, Mamoru Doi, Hakim L. Malasan, Junji Hayano

We introduce the Dichroic-Mirror Camera (DMC), an instrument developed at the University of Tokyo which is capable of performing simultaneous imaging in fifteen bands. The main feature of the DMC is the dichroic mirrors, which split incoming light into red and blue components. Combination of dichroic mirrors split light from the telescope focus into fifteen

Eric Bonnet, Bernard Borderie, Nicolas Le Neindre, Marie-France Rivet

Fragment properties of hot fragmenting sources of similar sizes produced in central and semi-peripheral collisions are compared in the excitation energy range 5-10 AMeV. For semi-peripheral collisions a method for selecting compact quasi-projectiles sources in velocity space similar to those of fused systems (central collisions) is proposed. The two major re

A. Rod Gover

On an even conformal manifold $(M,c)$, such that the critical GJMS operator has non-trivial kernel, we identify and discuss the role of a finite dimensional vector space $N(Q)$ of functions determined by the conformal structure. Using these we describe an infinite dimensional class of functions that cannot be the Q-curvature $Q^g$ for any $g$ in $c$. If cert

Hiroshi Imai, Masahito Hayashi

For a unified analysis on the phase estimation, we focus on the limiting distribution. It is shown that the limiting distribution can be given by the absolute square of the Fourier transform of $L^2$ function whose support belongs to $[-1,1]$. Using this relation, we study the relation between the variance of the limiting distribution and its tail probabilit

K. A. Dancer, J. Links

Two universal spectral parameter-dependent Lax operators are presented in terms of the elements of the Drinfeld double $D(D_3)$ of the dihedral group $D_3$. Applying representations of $D(D_3)$ to these yields matrix solutions of the Yang-Baxter equation with spectral parameter.

Shelley A. Wright, James E. Larkin, David R. Law, Charles C. Steidel

We present 0.2" resolution near-infrared integral field spectroscopy of H-alpha emission from six star forming galaxies at z~1.6 (look-back time of ~9.6 Gyr). These observations were obtained with OSIRIS using the Keck Laser Guide Star Adaptive Optics system. All sources have a compact spatial extent of ~1", with an average half light radius of r=2.9

Christian Baer

We extend several classical eigenvalue estimates for Dirac operators on compact manifolds to noncompact, even incomplete manifolds. This includes Friedrich's estimate for manifolds with positive scalar curvature as well as the author's estimate on surfaces.

Nicolas Fernandez-Garcia, Oscar Rosas-Ortiz

Darboux-deformations of short range one-dimensional potentials are constructed by means of Gamow-Siegert functions (resonance states). Results include both Hermitian and non-Hermitian short range potentials which are exactly solvable. As illustration, the method is applied to square wells and barriers for which the transmission coefficient is a superposition

R. Nuriyev

The study consists of two parts. Objective of the first part is modern language constructions responsible for algorithmically insolvability of parallelizing problem. Second part contains several ways to modify the constructions to make the problem algorithmically solvable

Paolo Lipparini

We prove, in ZFC alone, some new results on regularity and decomposability of ultrafilters. We also list some problems, and furnish applications to topological spaces and to extended logics.

Roni Harnik, Graham D. Kribs

A stable Dirac fermion with four-fermion interactions to leptons suppressed by a scale Lambda ~ 1 TeV is shown to provide a viable candidate for dark matter. The thermal relic abundance matches cosmology, while nuclear recoil direct detection bounds are automatically avoided in the absence of (large) couplings to quarks. The annihilation cross section in the

C. M. Chandrashekar

Quantum recurrence theorem holds for quantum systems with discrete energy eigenvalues and fails to hold in general for systems with continuous energy. We show that during quantum walk process dominated by interference of amplitude corresponding to different paths fail to satisfy the complete quantum recurrence theorem. Due to the revival of the fractional wa

The NA49 Collaboration

Results are presented on event-by-event fluctuations of transverse momenta $p_T$ in central Pb+Pb interactions at 20$A$, 30$A$, 40$A$, 80$A$, and 158$A$ GeV. The analysis was performed for charged particles at forward center-of-mass rapidity ($1.1 < y^{*}_π < 2.6$). Three fluctuation measures were studied: the distribution of average transverse momentum - $M

Christian P. Morath, John A. Seamons, John L. Reno, Michael P. Lilly

A low-temperature upturn of the Coulomb drag resistivity measured in an undoped electron-hole bilayer (uEHBL) device, possibly manifesting from exciton formation or condensation, was recently observed. The effects of density imbalance on this upturn are examined. Measurements of drag as a function of temperature in a uEHBL with a 20 nm wide Al$_{.90}$Ga$_{.1

Michael Burns, Kyoungchul Kong, Konstantin T. Matchev, Myeonghun Park

We propose to use the MT2 concept to measure the masses of all particles in SUSY-like events with two unobservable, identical particles. To this end we generalize the usual notion of MT2 and define a new MT2(n,p,c) variable, which can be applied to various subsystem topologies, as well as the full event topology. We derive analytic formulas for its endpoint

Jean Bérard

We consider a branching-selection particle system on $\Z$ with $N \geq 1$ particles. During a branching step, each particle is replaced by two new particles, whose positions are shifted from that of the original particle by independently performing two random walk steps according to the distribution $p δ_{1} + (1-p) δ_{0}$, from the location of the original

Vladimir Georgescu

We discuss criteria for a self-adjoint operator on L^2(X) to have empty essential spectrum. We state a general result for the case of a locally compact abelian group X and give examples for X=R^n.

Surhud More, Jo Bovy, David W. Hogg

Conservation of the phase-space density of photons plus Lorentz invariance requires that the cosmological luminosity distance be larger than the angular diameter distance by a factor of $(1+z)^2$, where $z$ is the redshift. Because this is a fundamental symmetry, this prediction--known sometimes as the &#34;Etherington relation&#34; or the &#34;Tolman test&#

Eliyahu Meital, Liberman Eran, Schaps Mary, Teicher Mina

Kwai Man Fan proved that if the intersection lattice of a line arrangement does not contain a cycle, then the fundamental group of its complement is a direct sum of infinite and cyclic free groups. He also conjectured that the converse is true as well. The main purpose of this paper is to prove this conjecture

Xinjia Chen

In this paper, we have established a new framework of truncated inverse sampling for estimating mean values of non-negative random variables such as binomial, Poisson, hyper-geometrical, and bounded variables. We have derived explicit formulas and computational methods for designing sampling schemes to ensure prescribed levels of precision and confidence for

Nikolay H. Balov

For a class of integral operators with kernels metric functions on manifold we find some necessary and sufficient conditions to have finite rank. The problem we pose has a stochastic nature and boils down to the following alternative question. For a random sample of discrete points, what will be the probability the symmetric matrix of pairwise distances to h

Rathin Adhikari, Jens Erler, Ernest Ma

The three electroweak doublet neutrinos $ν_{e,μ,τ}$ of the Standard Model may acquire small seesaw masses, using either three Majorana fermion singlets $N$ or three Majorana fermion triplets $(Σ^+,Σ^0,Σ^-)$. It is well-known that the former accommodates the U(1) gauge symmetry $B-L$. It has also been shown some years ago that the latter supports a new $U(1)_

Bernhard Keller, Dong Yang, Guodong Zhou

We determine the Hall algebra, in the sense of Toen, of the algebraic triangulated category generated by a spherical object.

Dmitriy Bilyk, Michael T. Lacey, Ioannis Parissis, Armen Vagharshakyan

Let A_N be an N-point distribution in the unit square in the Euclidean plane. We consider the Discrepancy function D_N(x) in two dimensions with respect to rectangles with lower left corner anchored at the origin and upper right corner at the point x. This is the difference between the actual number of points of A_N in such a rectangle and the expected numbe

Pablo I. Hurtado, Pedro L. Garrido

We study the distribution of the time-integrated current in an exactly-solvable toy model of heat conduction, both analytically and numerically. The simplicity of the model allows us to derive the full current large deviation function and the system statistics during a large deviation event. In this way we unveil a relation between system statistics at the e

Can Kilic, Steffen Schumann, Minho Son

Recently it was shown that there is a class of models in which colored vector and scalar resonances can be copiously produced at the Tevatron with decays to multijet final states, consistent with all experimental constraints and having strong discovery potential. We investigate the collider phenomenology of TeV scale colored resonances at the LHC and demonst

Nicolas Yunes, David N. Spergel

Chern-Simons modified gravity is a string-theory and loop-quantum-gravity inspired effective theory that modifies General Relativity by adding a parity-violating Pontryagin density to the Einstein-Hilbert action multiplied by a coupling scalar. We strongly constrain non-dynamical Chern-Simons modified gravity with a timelike Chern-Simons scalar through obser

Gonzalo A. Palma, Subodh P. Patil

In this paper we revisit the formulation of scalar field theories on de Sitter backgrounds subject to the generalized uncertainty principle (GUP). The GUP arises in several contexts in string theory, but is most readily thought of as resulting from using strings as effective probes of geometry, which suggests an uncertainty relation incorporating the string

A. R. Bosco de Magalhães, Adélcio C. Oliveira

The attenuation of fringe contrast in a Ramsey interferometer induced by the atom-field interaction is analyzed. We show that short-time power series expansion is not the proper tool to find the relevant time scale for such process. Analytical expressions to quantify the relevant time scale for the fringe contrast decay and to characterize the long-term effe

Terence Tao, Tamar Ziegler

The inverse conjecture for the Gowers norms $U^d(V)$ for finite-dimensional vector spaces $V$ over a finite field $\F$ asserts, roughly speaking, that a bounded function $f$ has large Gowers norm $\|f\|_{U^d(V)}$ if and only if it correlates with a phase polynomial $ϕ= e_\F(P)$ of degree at most $d-1$, thus $P: V \to \F$ is a polynomial of degree at most $d-

H. H. Alharbi, H. A. Alhendi, F. S. Alhakami

The generalised deformed su_{q}(2) model is applied to 79 superdeformed bands in the region A~190. The transition energies and the moments of inertia are calculated within the model, Its validity is investigated by comparing it with the experimental data. Both the standard su_{q}(2) and the generalized one fail to account for the uprising and the downturn of

Diptendu Bhowmick, L. Sunil Chandran

A $k$-dimensional box is the cartesian product $R_1 \times R_2 \times ... \times R_k$ where each $R_i$ is a closed interval on the real line. The {\it boxicity} of a graph $G$, denoted as $box(G)$, is the minimum integer $k$ such that $G$ can be represented as the intersection graph of a collection of $k$-dimensional boxes: that is two vertices are adjacent

T. G. Arshakian, J. Leon-Tavares, A. P. Lobanov, V. H. Chavushyan

Variations of the optical continuum emission in the radio galaxy 3C 390.3 are compared to the properties of radio emission from the compact, sub-parsec-scale jet in this object. We showed that very long-term variations of optical continuum emission (>10 years) is correlated with the radio emission from the base of the jet located above the disk, while the op

Wen Zhao

We investigate the attractor solution in the coupled Yang-Mills field dark energy models with the general interaction term, and obtain the constraint equations for the interaction if the attractor solution exists. The research also shows that, if the attractor solution exists, the equation-of-state of the dark energy must evolve from $w_y>0$ to $w_y\le-1$, w

Yasunori Nomura, Jesse Thaler

Motivated by the galactic positron excess seen by PAMELA and ATIC/PPB-BETS, we propose that dark matter is a TeV-scale particle that annihilates into a pseudoscalar &#34;axion.&#34; The positron excess and the absence of an anti-proton or gamma ray excess constrain the axion mass and branching ratios. In the simplest realization, the axion is associated with

Stephane Demri, Ranko Lazic, Arnaud Sangnier

We study complexity of the model-checking problems for LTL with registers (also known as freeze LTL) and for first-order logic with data equality tests over one-counter automata. We consider several classes of one-counter automata (mainly deterministic vs. nondeterministic) and several logical fragments (restriction on the number of registers or variables an

Eran Nevo

We consider simplicial polytopes, and more general simplicial complexes, without missing faces above a fixed dimension. Sharp analogues of McMullen&#39;s generalized lower bounds, and of Barnette&#39;s lower bounds, are conjectured for these families of complexes. Some partial results on these conjectures are presented.

P. Di Vecchia, A. Liccardo, R. Marotta, F. Pezzella

Using the field theoretical approach introduced by Cremades, Ibanez and Marchesano for describing open strings attached to D9 branes having different magnetizations, we give a procedure for determining the Kaehler metrics of those open strings in toroidal compactifications.

Dorit Aharonov, Michael Ben-Or, Elad Eban

The widely held belief that BQP strictly contains BPP raises fundamental questions: Upcoming generations of quantum computers might already be too large to be simulated classically. Is it possible to experimentally test that these systems perform as they should, if we cannot efficiently compute predictions for their behavior? Vazirani has asked: If predictin

Heinz-Peter Breuer, Jyrki Piilo

It is shown that non-Markovian master equations for an open system which are local in time can be unravelled through a piecewise deterministic quantum jump process in its Hilbert space. We derive a stochastic Schrödinger equation that reveals how non-Markovian effects are manifested in statistical correlations between different realizations of the process. M

Davide Rossini, Alessandro Silva, Giuseppe Mussardo, Giuseppe Santoro

We study the nonequilibrium dynamics of the Quantum Ising Model following an abrupt quench of the transverse field. We focus on the on-site autocorrelation function of the order parameter, and extract the phase coherence time $τ^ϕ_Q$ from its asymptotic behavior. We show that the initial state determines $τ^ϕ_Q$ only through an effective temperature set by i

Ana Bela Cruzeiro

We characterize the solution of Navier-Stokes equation as a stochastic geodesic on the diffeomorphisms group, thus generalizing Arnold&#39;s description of the Euler flow.

A. D. Lange, K. Pilch, A. Prantner, F. Ferlaino

We present an analytic model to calculate the atomic scattering length near a Feshbach resonance from data on the molecular binding energy. Our approach considers finite-range square-well potentials and can be applied near broad, narrow, or even overlapping Feshbach resonances. We test our model on Cs$_2$ Feshbach molecules. We measure the binding energy usi

Omer F. Dayi

The dynamics of a spin--1/2 neutral particle possessing electric and magnetic dipole moments interacting with external electric and magnetic fields in noncommutative coordinates is obtained. Noncommutativity of space is interposed in terms of a semiclassical constrained Hamiltonian system. The relation between the quantum phase acquired by a particle interac

G. Brida, M. Genovese, M. Gramegna, A. Meda

The knowledge of the density matrix of a quantum state plays a fundamental role in several fields ranging from quantum information processing to experiments on foundations of quantum mechanics and quantum optics. Recently, a method has been suggested and implemented in order to obtain the reconstruction of the diagonal elements of the density matrix exploiti

O. M. Umurhan, G. Shaviv

This paper discusses new perspectives and approaches to the problem of disk dynamics where, in this study, we focus on the effects of viscous instabilities influenced by boundary effects. The Boussinesq approximation of the viscous large shearing box equations is analyzed in which the azimuthal length scale of the disturbance is much larger than the radial a

R. L. Flack

The NEMO 3 experiment is located in the Modane Underground Laboratory and has been taking data since 2003 with seven isotopes. It is searching for the double beta decay process with two or zero neutrinos emitted in the final state. Precision measurements of the half-life of the isotopes due to two neutrino double beta decay have been performed and new result

Yuliy Baryshnikov, Wil Brady, Andrew Bressler, Robin Pemantle

We analyze several families of two-dimensional quantum random walks. The feasible region (the region where probabilities do not decay exponentially with time) grows linearly with time, as is the case with one-dimensional QRW. The limiting shape of the feasible region is, however, quite different. The limit region turns out to be an algebraic set, which we ch

Hirokazu Nishimura

Just as the Jacobi identity of vector fields is a natural consequence of the general Jacobi identity of microcubes in synthetic differential geometry, it is to be shown in this paper that the graded Jacobi identity of the Frolicher-Nijenhuis bracket is also a natural consequence of the general Jacobi identity.

Elcio Abdalla, Owen Pavel Fernandez Piedra, Jeferson de Oliveira, C. Molina

We consider black $p$-brane solutions of the low energy string action, computing scalar perturbations. Using standard methods, we derive the wave equations obeyed by the perturbations and treat them analytically and numerically. We have found that tensorial perturbations obtained via a gauge-invariant formalism leads to the same results as scalar perturbatio

Huayi Chen

We prove an arithmetic analogue of Fujita&#39;s approximation theorem in Arakelov geometry, conjectured by Moriwaki, by using slope method and measures associated to $\mathbb R$-filtrations.

Bruno Martelli

We extend Matveev&#39;s complexity of 3-manifolds to PL compact manifolds of arbitrary dimension, and we study its properties. The complexity of a manifold is the minimum number of vertices in a simple spine. We study how this quantity changes under the most common topological operations (handle additions, finite coverings, drilling and surgery of spheres, p

A. Baumann, J. Lorrmann, C. Deibel, V. Dyakonov

We investigated the charge carrier mobility in pristine poly(3-hexyl thiophene-2,5-diyl) (P3HT):[6,6]-phenyl-C61 butyric acid methyl ester (PCBM) blend devices by applying the time resolved photoconductivity experiment in dependence on the donor:acceptor ratio. We observe a bipolar transport in all studied samples ranging from pure polymer to polymer:fullere

J. Barranco, O. G. Miranda, T. I. Rashba

New limits on the weak mixing angle and on the electron neutrino effective charge radius in the low energy regime, below 100 MeV, are obtained from a combined fit of all electron-(anti)neutrino electron elastic scattering measurements. We have included the recent TEXONO measurement with a CsI (Tl) detector. Only statistical error of this measurement has been

Frederic Deliot

This article describes the analyses presented at the XXVIII Physics in Collision conference about top quark cross sections performed at Tevatron.

Simon Hochgerner, Luis Garcia-Naranjo

Via compression ([11, 7]) we write the $n$-dimensional Chaplygin sphere system as an almost Hamiltonian system on $T^*SO(n)$ with internal symmetry group $SO(n-1)$. We show how this symmetry group can be factored out, and pass to the fully reduced system on (a fiber bundle over) $T^*S^{n-1}$. This approach yields an explicit description of the reduced system

Edan Scriven, B. J. Powell

We calculate the effective Coulomb repulsion between electrons/holes, U, and site energy for an isolated BEDT-TTF [bis(ethylenedithio)tetrathiafulvalene] molecule in vacuo. U=4.2 \pm 0.1 eV for 44 experimental geometries taken from a broad range of conformations, polymorphs, anions, temperatures, and pressures (the quoted `error&#39; is one standard deviatio

Yang Su, Yang Chen, Ji Yang, Bon-Chul Koo

The young composite supernova remnant (SNR) Kesteven 75, with a pulsar wind nebula at its center, has an unusual morphology with a bright southern half-shell structure in multiwavelengths. The distance to Kes 75 has long been uncertain. Aiming to address these issues, we have made millimeter spectroscopic observations of the molecular gas toward the remnant.

Michikazu Kobayashi, Yuki Kawaguchi, Muneto Nitta, Masahito Ueda

We investigate the collision dynamics of two non-Abelian vortices and find that, unlike Abelian vortices, they neither reconnect themselves nor pass through each other, but create a rung between them in a topologically stable manner. Our predictions are verified using the model of the cyclic phase of a spin-2 spinor Bose-Einstein condensate.

Paul Sutcliffe

It is known that including vector mesons stabilizes the size of a Skyrmion without the need for a Skyrme term. This paper provides the first results for static multi-Skyrmions in such a theory. The rational map ansatz is used to investigate multi-Skyrmions in a theory which includes the omega vector meson and has no Skyrme term. Bound states with baryon numb

H. L. Ge, C. Giunti, Q. Y. Liu

We present the results of a Bayesian analysis of solar and KamLAND neutrino data in the framework of three-neutrino mixing. We adopt two approaches for the prior probability distribution of the oscillation parameters Delta m^2_{21}, sin^2 theta_{12}, sin^2 theta_{13}: 1) a traditional flat uninformative prior; 2) an informative prior which describes the limi

M. R. Kirakosyan, A. V. Leonidov

Energy losses of fast color particles in random inhomogeneous color medium created in high energy nuclear collisions are estimated.

Qasem Exirifard

We argue that Solar system tests do not rule out 1/R gravity at least due to the reason addressed in Phys. Rev. D 74 (2006) 121501 [astro-ph/0610483] (ref. [1]) and subsequent published papers. Ref. [1] has not only modified the Einstein-Hilbert action but also has changed the boundary conditions since they altered the equations of motion. In Einstein-Hilber

Amitabha Bagchi, Garima Lahoti

We argue that relationships between Web pages are functions of the user&#39;s intent. We identify a class of Web tasks - information-gathering - that can be facilitated by a search engine that provides links to pages which are related to the page the user is currently viewing. We define three kinds of intentional relationships that correspond to whether the

D. B. Tretyakov, I. I. Beterov, V. M. Entin, I. I. Ryabtsev

We present our results on the experiments with cold Rb Rydberg atoms in a magneto-optical trap (MOT). Characteristic features of our experiment were the excitation of Rydberg atoms in a small volume within the cold atom cloud and sorting of the measured signals and spectra over the number of registered Rydberg atoms. We have measured the effective lifetime o

Hiroshi Masui

One of the most striking results is the large elliptic flow ($v_2$) at RHIC. Detailed mass and transverse momentum dependence of elliptic flow are well described by ideal hydrodynamic calculations for $p_{\mathrm{T}} < $ 1 GeV/c, and by parton coalescence/recombination picture for $p_{\mathrm{T}} = 2 - 6$ GeV/c. The systematic error on $v_2$ is dominated by

Anton Kapustin, Lev Rozansky, Natalia Saulina

We study boundary conditions and defects in a three-dimensional topological sigma-model with a complex symplectic target space X (the Rozansky-Witten model). We show that boundary conditions correspond to complex Lagrangian submanifolds in X equipped with complex fibrations. The set of boundary conditions has the structure of a 2-category; morphisms in this

Sirichai Chongchitnan

Models in which dark energy interacts with dark matter have been proposed in the literature to help explain why dark energy should only come to dominate in recent times. In this paper, we present a dynamical framework to calculate cosmological perturbations for a general quintessence potential and interaction term. Our formalism is built upon the powerful ph

Ilias Cholis, Douglas P. Finkbeiner, Lisa Goodenough, Neal Weiner

Recently published results from the PAMELA experiment have shown conclusive evidence for an excess of positrons at high (~ 10 - 100 GeV) energies, confirming earlier indications from HEAT and AMS-01. Such a signal is generally expected from dark matter annihilations. However, the hard positron spectrum and large amplitude are difficult to achieve in most con

Eylee Jung, Mi-Ra Hwang, DaeKil Park, Jin-Woo Son

Three-tangle for the rank-three mixture composed of Greenberger-Horne-Zeilinger, W and flipped W states is analytically calculated. The optimal decompositions in the full range of parameter space are constructed by making use of the convex-roof extension. We also provide an analytical technique, which determines whether or not an arbitrary rank-3 state has v

Shigeru Furuichi

The uniqueness theorem for a two-parameter extended relative entropy is proven. This result extends our previous one, the uniqueness theorem for a one-parameter extended relative entropy, to a two-parameter case. In addition, the properties of a two-parameter extended relative entropy are studied.

Marcelo Gleiser, Sara Imari Walker

The activation-polymerization-epimerization-depolymerization (APED) model of Plasson et al. has recently been proposed as a mechanism for the evolution of homochirality on prebiotic Earth. The dynamics of the APED model in two-dimensional spatially-extended systems is investigated for various realistic reaction parameters. It is found that the APED system al

Mitsutoshi Fujita, Yasuaki Hikida, Shinsei Ryu, Tadashi Takayanagi

We formulate a holographic description of effects of disorder in conformal field theories based on the replica method and the AdS/CFT correspondence. Starting with $n$ copies of conformal field theories, randomness with a gaussian distribution is described by a deformation of double trace operators. After computing physical quantities, we take the $n \to 0$

Markus Weigand, Bartel Van Waeyenberge, Arne Vansteenkiste, Michael Curcic

The bistability of the core magnetization of nano-scaled magnets with a magnetic vortex configuration has great potential for data storage applications. To exploit this, reliable switching between the two possible states is needed. Time resolved x-ray microscopy was used to study the response of the vortex core to excitation pulses at sub-ns timescales and i

James G. Analytis, Jiun-Haw Chu, Ann S. Erickson, Chris Kucharczyk

We have studied the intrinsic normal and superconducting properties of the oxypnictide LaFePO. These samples exhibit bulk superconductivity and the evidence suggests that stoichiometric LaFePO is indeed superconducting, in contrast to other reports. We find that superconductivity is independent of the interplane residual resistivity $ρ_0$ and discuss the imp

Leonard Adleman, Mark Schilling

Political polls achieve their results by sampling a small number of potential voters rather than the population as a whole. This leads to sampling error which most polling agencies dutifully report. But factors such as nonrepresentative samples, question wording and nonresponse can produce non-sampling errors. While pollsters are aware of such errors, they a

Luis Felipe Tabera

In this paper we present three related results on the subject of fields of parametrization. Let C be a rational curve over a field of characteristic zero. Let K be a field finitely generated over Q, such that it is a field of definition of C but not a field of parametrization. It is known that there are quadratic extensions of K that parametrize C. First, we

Thomas P. Sotiriou

There has been a recent stimulus in the study of alternative theories of gravity lately, mostly triggered from combined motivation coming from cosmology/astrophysics and high energy physics. Among the proposed theories, one that has attracted much attention is f(R) gravity. It is certainly debatable whether such a simplistic modification of General Relativit

G. D. Garcia, F. O. Sanchez-Varretti, F. Roma, A. J. Ramirez-Pastor

A simple statistical mechanical approach for studying multilayer adsorption of interacting polyatomic adsorbates (k-mers) has been presented. The new theoretical framework has been developed on a generalization in the spirit of the lattice-gas model and the classical Bragg-Williams (BWA) and quasi-chemical (QCA) approximations. The derivation of the equilibr

Jean-Francois Genat, Gary Varner, Fukun Tang, Henry Frisch

The development of large-area homogeneous photo-detectors with sub-millimeter path lengths for direct Cherenkov light and for secondary-electrons opens the possibility of large time-of-flight systems for relativistic particles with resolutions in the pico-second range. Modern ASIC techniques allow fast multi-channel front-end electronics capable of sub-pico-

Yina Wu, Mingqiang Bao, Alexander Khitun, Ji-Young Kim

We demonstrate a three-terminal spin wave-based device utilizing spin wave interference. The device consists of three coplanar transmission lines inductively coupled to the 100nm thick CoFe film. Two spin wave signals are excited by microwave fields produced by electric current in two sets of lines, and the output signal is detected by the third set. The ini

Alexander Khitun, Dmitri E. Nikonov, Kang L. Wang

We propose and analyze a spin wave amplifier aimed to enhance the amplitude of the propagating spin wave via the magnetoelectric effect. The amplifier is a two-layer multiferroic structure, which comprises piezoelectric and ferromagnetic materials. By applying electric field to the piezoelectric layer, the stress is produced. In turn, the stress changes the

Theodor Asavei, Timo A. Nieminen, Norman R. Heckenberg, Halina Rubinsztein-Dunlop

Two-photon photopolymerization of UV curing resins is an attractive method for the fabrication of microscopic transparent objects with size in the tens of micrometers range. We have been using this method to produce three-dimensional structures for optical micromanipulation, in an optical system based on a femtosecond laser. By carefully adjusting the laser

Alberto Della Vedova

An asymptotic formula for the Tian-Paul CM-line of a flat family blown-up at a flat closed sub-scheme is given. As an application we prove that the blow-up of a polarized manifold along a (relatively) Chow-unstable submanifold admits no (extremal) constant scalar curvature Kahler metrics in classes making the exceptional divisors sufficiently small. Moreover

Darryl Farber, Akhlesh Lakhtakia

Scenario planning may assist us in harnessing the benefits of nanotechnology and managing the associated risks for the good of the society. Scenario planning is a way to describe the present state of the world and develop several hypotheses about the future of the world, thereby enabling discussions about how the world ought to be. Scenario planning thus is

Nalini Joshi

A new direct method of obtaining reductions of the Toda equation is described. We find a canonical and complete class of all possible reductions under certain assumptions. The resulting equations are ordinary differential-difference equations, sometimes referred to as delay-differential equations. The representative equation of this class is hypothesized to

Tomas Feder, Shubha U. Nabar, Evimaria Terzi

Motivated by recently discovered privacy attacks on social networks, we study the problem of anonymizing the underlying graph of interactions in a social network. We call a graph (k,l)-anonymous if for every node in the graph there exist at least k other nodes that share at least l of its neighbors. We consider two combinatorial problems arising from this no

William A. Edelstein, Arthur D. Edelstein

Computerized touchscreen &#34;Direct Recording Electronic&#34; DRE voting systems have been used by over 1/3 of American voters in recent elections. In many places, insufficient DRE numbers in combination with lengthy ballots and high voter traffic have caused long lines and disenfranchised voters who left without voting. We have applied computer queuing sim

R. Nuriyev

The problem of detecting of information and logically independent (DILD) steps in programs is a key for equivalent program transformations. Here we are considering the problem of independence of loop iterations, the concentration of massive data processing and hence the most challenge construction for parallelizing. We introduced a separated form of loops wh

Ernest Ma

The origin of neutrino mass is usually attributed to a seesaw mechanism, either through a heavy Majorana fermion singlet (version 1) or a heavy scalar triplet (version 2). Recently, the idea of using a heavy Majorana fermion triplet (version 3) has gained some attention. This is a review of the basic idea involved, its U(1) gauge extension, and some recent d

Marcelo Ris, Junior Barrera, David C. Martins

This paper presents the formulation of a combinatorial optimization problem with the following characteristics: i.the search space is the power set of a finite set structured as a Boolean lattice; ii.the cost function forms a U-shaped curve when applied to any lattice chain. This formulation applies for feature selection in the context of pattern recognition

Marco Pacini

L. Maino constructed a moduli space for enriched stable curves, by blowing-up the moduli space of Deligne-Mumford stable curves. We introduce enriched spin curves, showing that a parameter space for these objects is obtained by blowing-up the moduli space of spin curves.

Jeremy Kahn, Mikhail Lyubich, Lasse Rempe

We study the affine orbifold laminations that were constructed by Lyubich and Minsky. An important question left open in their construction is whether these laminations are always locally compact. We show that this is not the case. The counterexample we construct has the property that the regular leaf space contains (many) hyperbolic leaves that intersect th

L. D. Anderson, T. M. Bania

We resolve the kinematic distance ambiguity for 266 inner Galaxy HII regions out of a sample of 291 using existing HI and 13CO sky surveys. Our sample contains all HII regions with measured radio recombination line (RRL) emission over the extent of the 13CO Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey (18 deg, < l < 55 deg.