May 2009 arXiv papers — page 27

E. Mocchiutti, O. Adriani, G. C. Barbarino, G. A. Bazilevskaya

The 15th of June 2006, the PAMELA satellite-borne experiment was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. The apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail counter scintillator and a

T. Caldwell, A. Roccaro, T. Sahin, H. Yegoryan

Carbon-tetrafluoride (CF4) is used as a counting gas in particle detectors, but some of its properties that are of interest for large time-projection chambers are not well known. We measure the mean energy, which is proportional to the diffusion coefficent, and the attentuation coefficient of electron propagation in CF4 gas using a 10-liter dark matter detec

David A. van Dyk, Steven DeGennaro, Nathan Stein, William H. Jefferys

Color-Magnitude Diagrams (CMDs) are plots that compare the magnitudes (luminosities) of stars in different wavelengths of light (colors). High nonlinear correlations among the mass, color, and surface temperature of newly formed stars induce a long narrow curved point cloud in a CMD known as the main sequence. Aging stars form new CMD groups of red giants an

Hamza Fekir

In order to adapt to the liberalization of the financial sphere started in the Eighties, marked in particular by the end of the framing of credit, the disappearance of the various forms of protection of the State whose profited the banks, and the privatization of the near total of the establishments in Europe, the banking regulation evolved to a prudential a

René David

I give a proof of the confluence of combinatory strong reduction that does not use the one of lambda-calculus. I also give simple and direct proofs of a standardization theorem for this reduction and the strong normalization of simply typed terms.

Bodhisattva Sen, Moulinath Banerjee, Michael Woodroofe, Mario Mateo

Whether a dwarf spheroidal galaxy is in equilibrium or being tidally disrupted by the Milky Way is an important question for the study of its dark matter content and distribution. This question is investigated using 328 recent observations from the dwarf spheroidal Leo I. For Leo I, tidal disruption is detected, at least for stars sufficiently far from the c

Boudewijn F. Roukema

The missing fluctuations problem in cosmic microwave background observations is naturally explained by well-proportioned small universe models. Among the well-proportioned models, the Poincare dodecahedral space is empirically favoured. Does gravity favour this space? The residual gravity effect is the residual acceleration induced by weak limit gravity from

E. Kyriakopoulos

We present two rotating black hole solutions with axion $ξ$, dilaton $ϕ$ and two U(1) vector fields. By applying the "Newman-Janis trick" to a metric with 3 arbitrary parameters we find a rotating metric $g_{μν}$ with 4 such parameters $(M, a, Q_E, Q_M)$, and then a solution with this $g_{μν}$ as metric. Our solution is asymptotically flat and has an

Alain Cournier, Swan Dubois, Vincent Villain

A snap-stabilizing protocol, starting from any configuration, always behaves according to its specification. In this paper, we present a snap-stabilizing protocol to solve the message forwarding problem in a message-switched network. In this problem, we must manage resources of the system to deliver messages to any processor of the network. In this purpose,

Gerald Schubert, Holger Fehske

In this lecture note we demonstrated the capability of the local distribution approach to the problem of quantum percolation.

Paul H. Frampton

Observational searches for Intermediate-Mass Black Holes (IMBHs), defined to have masses between 30 and 300,000 solar masses, provide limits which allow up to ten percent of what is presently identified as halo dark matter to be in the form of IMBHs. These concentrate entropy so efficiently that the halo contribution can be bigger than the core supermassive

C. Esteban, F. Bresolin, M. Peimbert, J. Garcia-Rojas

We present very deep spectrophotometry of 14 bright extragalactic HII regions belonging to spiral, irregular, and blue compact galaxies. The data for 13 objects were taken with the HIRES echelle spectrograph on the Keck I telescope. We have measured CII recombination lines in 10 of the objects and OII recombination lines in 8 of them. We have determined elec

D. Garcia, O. F. K. Kalenda, M. Maestre

We investigate certain envelopes of open sets in dual Banach spaces which are related to extending holomorphic functions. We give a variety of examples of absolutely convex sets showing that the extension is in many cases not possible. We also establish connections to the study of iterated weak* sequential closures of convex sets in the dual of separable spa

Martin Kolar

We consider an alternative approach to a fundamental CR invariant - the Catlin multitype. It is applied to a general smooth hypersurface in $\mathbbC^{n+1}$, not necessarily pseudoconvex. Using this approach, we prove biholomorphic equivalence of models, and give an explicit description of biholomorphisms between different models. A constructive finite algor

I. Kostyukov, E. Nerush, A. Pukhov, V. Seredov

We present an analytical model for electron self-injection in nonlinear, multidimensional plasma wave excited by short laser pulse in the bubble regime or by short electron beam in the blowout regime. In this regimes, which are typical for electron acceleration in the last experiments, the laser radiation pressure or the electron beam charge pushes out backg

D. Mubayi, G. Turan

Polynomial algorithms are given for the following two problems: given a graph with $n$ vertices and $m$ edges, where $m \ge 3 n^{3/2}$, find a complete balanced bipartite subgraph with parts about $\ln n/(\ln (n^2/m))$, given a graph with $n$ vertices, find a decomposition of its edges into complete balanced bipartite graphs having altogether $O(n^2 / \ln n)

Timo Lewke

Borexino is a low threshold liquid-scintillator detector for solar neutrinos located in the LNGS underground laboratory, Italy. Because of the ultra-high radio purity it is the first experiment able to do a real time analysis of the low energetic solar neutrinos. A detection of the solar 7Be neutrinos with a rate of 47+-7 counts/day/100tons can be reported (

Minfeng Gu, Zhaoyu Chen, Xinwu Cao

The relationship between the black hole mass and velocity dispersion indicated with [O III] line width is investigated for a sample of 87 flat-spectrum radio quasars (FSRQs) selected from SDSS DR3 quasar catalogue. We found the M_bh - sigma_[O III] relation is deviated from Tremaine et al. relation for nearby inactive galaxies, with a larger black hole mass

Dalia Chakrabarty

The state of a non-relativistic gravitational dynamical system is known at any time $t$ if the dynamical rule, i.e. Newton's equations of motion, can be solved; this requires specification of the gravitational potential. The evolution of a bunch of phase space coordinates ${\bf w}$ is deterministic, though generally non-linear. We discuss the novel Bayesian

F. Neves, V. Chepel, D. Yu. Akimov, H. M. Araujo

A method is described that allows calibration and assessment of the linearity of response of an array of photomultiplier tubes. The method does not require knowledge of the photomultiplier single photoelectron response model and uses science data directly, thus eliminating the need for dedicated data sets. In this manner all photomultiplier working condition

M. N. Chernodub, H. Verschelde, V. I. Zakharov

We discuss the role of the magnetic degrees of freedom of the gluon plasma in its viscosity. The main assumption is that motions of the magnetic component and of the rest of the plasma can be considered as independent. The magnetic component in the deconfined phase is described by a three-dimensional (Euclidean) field theory. The parameters of the theory can

D. L. Clements, Glen Petitpas, D. Farrah, E. Hatziminaoglou

We present submillimetre observations of the z=3.653 quasar SDSS160705+533558 together with data in the optical and infrared. The object is unusually bright in the far-IR and submm with an IR luminosity of ~10^14 L_sun. We ascribe this luminosity to a combination of AGN and starburst emission, with the starburst forming stars at a rate of a few thousand sola

G. V. Lipunova, N. I. Shakura

We fit outbursts of two X-ray novae (Nova Monocerotis 1975=A0620-00 and Nova Muscae GS 1991=1124-683) using a time-dependent accretion disk model. The model is based on a new solution for a diffusion-type equation for the non-steady-state accretion and describes the evolution of a viscous alpha-disk in a binary system after the peak of an outburst, when matt

P. S. Shternin, D. G. Yakovlev

We study plasma effects on radiative transitions (e.g., decay of excited states of atoms or atomic nuclei) in a dense plasma at the transition frequencies $ω\lesssim ω_p$ (where $ω_p$ is the electron plasma frequency). The decay goes through four channels -- the emission of real transverse and longitudinal plasmons as well as the emission of virtual transver

Jean-Christophe Pain, Franck Gilleron, Jacques Bauche, Claire Bauche-Arnoult

The impact of the third (skewness) and fourth (kurtosis) reduced centered moments on the statistical modeling of E1 lines in complex atomic spectra is investigated through the use of Gram-Charlier, Normal Inverse Gaussian and Generalized Gaussian distributions. It is shown that the modeling of unresolved transition arrays with non-Gaussian distributions may

Michael Aumer, James J. Binney

We use proper motions and parallaxes from the new reduction of Hipparcos data and Geneva-Copenhagen radial velocities for a complete sample of ~15000 main-sequence and subgiant stars, and new Padova isochrones to constrain the kinematics and star-formation history of the solar neighbourhood. We rederive the solar motion and the structure of the local velocit

Richard Williams, Christian S. Fischer

We discuss the impact of including corrections beyond single gluon exchange in light mesons within the nonperturbative framework of Dyson-Schwinger equations (DSE) and Bethe-Salpeter equations (BSE). We do this by considering unquenching effects in the form of hadronic resonance contributions, notably pion exchange, and by the inclusion of the dominant gluon

Angelo Di Iorio, Fabio Vitali, Davide Rossi, Stefano Zacchiroli

The Web 2.0 fosters the creation of communities by offering users a wide array of social software tools. While the success of these tools is based on their ability to support different interaction patterns among users by imposing as few limitations as possible, the communities they support are not free of rules (just think about the posting rules in a commun

Wei-Tou Ni

Inflationary cosmology is successful in explaining a number of outstanding cosmological issues including the flatness, the horizon and the relic issues. More spectacular is the experimental confirmation of the structure as arose from the inflationary quantum fluctuations. However, the physics in the inflationary era is unclear. Polarization observations of C

Y. Wang, C. R. Kaiser, R. Laing, P. Alexander

We present an analytical model for jets in Fanaroff & Riley Class I (FRI) radio galaxies, in which an initially laminar, relativistic flow is surrounded by a shear layer. We apply the appropriate conservation laws to constrain the jet parameters, starting the model where the radio emission is observed to brighten abruptly. We assume that the laminar flow fil

Christian Kellermann, Christian S. Fischer

We summarise results for the running coupling from the four-gluon vertex in Landau gauge, SU($N_c$) Yang-Mills theory as given by a combination of dressing functions of the vertex and the gluon propagator. These functions have been determined numerically from the corresponding set of Dyson-Schwinger equations. In the infrared we obtain a nontrivial infrared

Ying Zhang, Haozhao Liang, Jie Meng

The discrete single-particle spectra in both the Fermi and Dirac sea have been calculated by the imaginary time step (ITS) method for the Schr\"{o}dinger-like equation after avoiding the "tsunami" of the Dirac sea, i.e., the diving behavior of the single-particle level into the Dirac sea in the direct application of the ITS method for the Dirac equation. It

M. M. J. French, J. G. Analytis, A. Carrington, L. Balicas

This article describes new polar angle-dependent magnetoresistance (ADMR) measurements in the overdoped cuprate Tl$_2$Ba$_2$CuO$_{6+δ}$ over an expanded range of temperatures and azimuthal angles. These detailed measurements re-affirm the analysis of earlier data taken over a more restricted temperature range and at a single azimuthal orientation, in particu

Elisabetta Baracchini

We will present a review of the most interesting results on rare B decays from the B Factories, based on the data collected by the BaBar and Belle detectors at asymmetric $e^+ e^-$ colliders at the center of mass energy of the $Υ(4S)$ resonance.

Daniel Sonntag, Romàn R. Zapatrin

We present a method to geometrize massive data sets from search engines query logs. For this purpose, a macrodynamic-like quantitative model of the Information Retrieval (IR) process is developed, whose paradigm is inspired by basic constructions of Einstein's general relativity theory in which all IR objects are uniformly placed in a common Room. The Ro

Rafal Czyzykiewicz, Pawel Moskal

Based on recent COSY-11 results of measurements of total cross sections for the quasi-free pn-->pn eta reaction we determine the isospin I=0 component of the total cross section for the NN-->NN eta reaction down to the threshold. We show that the energy dependence of the total cross section ratios {σ_{I=0}(pn-->pn eta)}/{σ(pp-->pp eta)} and σ_{I=0}(pn-->pn e

D. E. Baldwin, W. Hereman

A recursion operator is an integro-differential operator which maps a generalized symmetry of a nonlinear PDE to a new symmetry. Therefore, the existence of a recursion operator guarantees that the PDE has infinitely many higher-order symmetries, which is a key feature of complete integrability. Completely integrable nonlinear PDEs have a bi-Hamiltonian stru

Jürgen Knödlseder

We report on observations of the Large Magellanic Cloud with the Fermi Gamma-Ray Space Telescope. The LMC is clearly detected with the Large Area Telescope (LAT) and for the first time the emission is spatially well resolved in gamma-rays. Our observations reveal that the bulk of the gamma-ray emission arises from the 30 Doradus region. We discuss this resul

Jean B. Lasserre

Given a compact parameter set $Y\subset R^p$, we consider polynomial optimization problems $(P_y$) on $R^n$ whose description depends on the parameter $y\inY$. We assume that one can compute all moments of some probability measure $ϕ$ on $Y$, absolutely continuous with respect to the Lebesgue measure (e.g. $Y$ is a box or a simplex and $ϕ$ is uniformly distr

Partha Ghose

A simple non-interferometric "quantum interrogation" method is proposed which uses evanescent wave sensing with frustrated total internal reflection on a surface. The simple method has the advantage over the original interferometric Elitzur-Vaidman method of being able to detect objects that are neither black nor non-diffracting and that are such tha

Yoshitaka Hatta, Takahiro Ueda, Bo-Wen Xiao

Using the AdS/CFT correspondence, we calculate the polarized structure functions in strongly coupled N=4 supersymmetric Yang-Mills theory deformed in the infrared. We find that the flavor singlet contribution to the g_1 structure function is vanishingly small, while the flavor non-singlet contribution shows the Regge behavior at small-x with an intercept sli

Gösta Gustafson

In high energy collisions saturation and multiple collisions are most easily accounted for in transverse coordinate space, while analyses in momentum space have been more suitable for calculating properties of exclusive final states. In this talk I describe an extension of Mueller's dipole cascade model, which attempts to combine the good features of bot

Alex D. Gottlieb, Thorsten Schumm

Bosonic Josephson junctions can be realized by confining ultracold gases of bosons in multi-well traps, and studied theoretically with the $M$-site Bose-Hubbard model. We show that canonical equilibrium states of the $M$-site Bose-Hubbard model may be approximated by mixtures of coherent states, provided the number of atoms is large and the total energy is c

Shizeng Lin, Xiao Hu

A new family of dynamic states are found in a stack of inductively coupled intrinsic Josephson junctions in the absence of an external magnetic field. In this state, $(2m_l+1)π$ phase kinks with integers $m_l$'s stack along the c axis and lock neighboring junction together. Large dc power is pumped into plasma oscillation via kinks at the cavity resonanc

Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz

In 1981 Hong and Kung proved a lower bound on the amount of communication needed to perform dense, matrix-multiplication using the conventional $O(n^3)$ algorithm, where the input matrices were too large to fit in the small, fast memory. In 2004 Irony, Toledo and Tiskin gave a new proof of this result and extended it to the parallel case. In both cases the l

M. R. Dietrich, B. B. Blinov

An inexpensive, easily programmed microcontroller is demonstrated for the fast frequency stabilization of an infrared fiber laser. The microcontroller manages all digitalization and processing, with external circuitry only providing buffering, amplification and overvoltage protection. Several convenient features are included to recover from common failure mo

Mark Israelit

In the present work a procedure is build up, that allows obtaining dark matter and cosmic acceleration in our 4 dimensional universe embedded in a 5 dim. manifold. Both, DM and the factor causing cosmic acceleration, as well ordinary matter are induced in the in the 4D space-time by a warped but empty from matter 5D bulk. The procedure is carried out in the

Marc Thuillard, Didier Fraix-Burnet

We describe the conditions under which a set of continuous variables or characters can be described as an X-tree or a split network. A distance matrix corresponds exactly to a split network or a valued X-tree if, after ordering of the taxa, the variables values can be embedded into a function with at most a local maxima and a local minima, and crossing any h

Takayuki Mizuno, Tsutomu Watanabe

We empirically investigate fluctuations in product prices in online markets by using a tick-by-tick price data collected from a Japanese price comparison site, and find some similarities and differences between product and asset prices. The average price of a product across e-retailers behaves almost like a random walk, although the probability of price incr

Guangyue Han, Brian Marcus, Yuval Peres

In this note, we show that small complex perturbations of positive matrices are contractions, with respect to a complex version of the Hilbert metric, on the standard complex simplex. We show that this metric can be used to obtain estimates of the domain of analyticity of entropy rate for a hidden Markov process when the underlying Markov chain has strictly

Toshiki Endo

This paper provides a relationship between a geometric structure of a suspended tree and the number of link components of the associated link diagram.

H. Aceves, H. Velazquez, F. Cruz

We determine both representations of the Fundamental Plane [Re Sig^a Ie^b and Re (Sig^2/Ie)^lambda] and the luminosity-effective phase space density [L fe^(-gamma)] scaling relation for N-body remnants of binary mergers of spiral-like galaxies. The main set of merger simulations involves a mass-ratio of the progenitors in the range of about 1:1 to 1:5, harbo

Takayuki Mizuno, Misako Takayasu

The density function of product life cycles in convenience stores is found to follow the Weibull distribution. To clarify the parameters that determine these life cycles, we introduce the conditional market share-defined as the probability that a product is selected by customers only if it had been previously purchased-and the market share without any condit

Keki M. Burjorjee

We recently reported that the simple genetic algorithm (SGA) is capable of performing a remarkable form of sublinear computation which has a straightforward connection with the general problem of interacting attributes in data-mining. In this paper we explain how the SGA can leverage this computational proficiency to perform efficient adaptation on a broad c

Markus Brodmann, Maryam Jahangiri, Cao Huy Linh

Let $d \in \N$ and let $\D^d$ denote the class of all pairs $(R,M)$ in which $R = \bigoplus_{n \in \N_0} R_n$ is a Noetherian homogeneous ring with Artinian base ring $R_0$ and such that $M$ is a finitely generated graded $R$-module of dimension $\leq d$. The cohomology table of a pair $(R,M) \in \D^d$ is defined as the family of non-negative integers $d_M:=

Paula S. Teixeira, Charles J. Lada, Kenneth Wood, Thomas P. Robitaille

We present 5 to 15 micron Spitzer Infrared Spectrograph (IRS) low resolution spectral data of a candidate debris disk around an M4.5 star identified as a likely member of the ~40 Myr old cluster NGC2547. The IRS spectrum shows a silicate emission feature, indicating the presence of warm, small, (sub)micron-sized dust grains in the disk. Of the fifteen previo

Tzu-Chieh Wei

The degree to which a pure quantum state is entangled can be characterized by the distance or angle to the nearest unentangled state. This geometric measure of entanglement is explored for bi-partite and multi-partite pure and mixed states. It is determined analytically for arbitrary two-qubit mixed states, generalized Werner, and isotropic states, and is al

Tiberiu Harko

The brane-world description of our universe entails a large extra dimension and a fundamental scale of gravity that might be lower by several orders of magnitude compared to the Planck scale. An interesting consequence of the brane-world scenario is in the nature of spherically symmetric vacuum solutions to the brane gravitational field equations, with prope

Chun-Hua Yuan, Li-Qing Chen, Weiping Zhang

We present a scheme for entanglement macroscopic atomic ensembles which are four spatially separate regions of an atomic cloud using cluster-correlated beams. We show that the cluster-type polarization-encoded entanglement could be mapped onto the long-lived collective ground state of the atomic ensembles, and the stored entanglement could be retrieved based

Taisuke Ozaki, Kengo Nishio, Hongming Weng, Hiori Kino

By first principle calculations, a dual spin filter effect under finite bias voltages is demonstrated in an antiferromagnetic junction of symmetric zigzag graphene nanoribbon (ZGNR). Unlike conventional spin filter devices using half metallic materials, the up- and down-spin electrons are unidirectionally filtered in the counter direction of the bias voltage

T. P. Singh

The black hole area theorem suggests that classical general relativity is the thermodynamic limit of a quantum statistics. The degrees of freedom of the statistical theory cannot be the spacetime metric. We argue that the statistical theory should be constructed from a noncommutative gravity, whose classical, and thermodynamic, approximation is Einstein grav

Fang Wang

We study the linearization of the Dirichlet-to-Neumann map for Poincaré-Einstein metrics in even dimensions on an arbitrary compact manifold with boundary. By fixing a suitable gauge, we make the linearized Einstein equation elliptic. In this gauge the linearization of the Dirichlet-to-Neumann map appears as the scattering matrix for an elliptic operator of

Annika H. G. Peter

One method to search for particle dark matter is to hunt down its annihilation products. In the Solar System, three potential types of signals of annihilation have been identified: neutrinos and gamma-rays from the Sun, and neutrinos from the Earth. Each of these signals depends sensitively on the orbital evolution of dark matter once it becomes bound to the

Alexander C. Thompson, Christopher J. Fluke, David G. Barnes, Benjamin R. Barsdell

Gravitational lensing calculation using a direct inverse ray-shooting approach is a computationally expensive way to determine magnification maps, caustic patterns, and light-curves (e.g. as a function of source profile and size). However, as an easily parallelisable calculation, gravitational ray-shooting can be accelerated using programmable graphics proce

Serguei A. Mokhov

This paper further introduces and formalizes a novel concept of self-forensics for automotive vehicles, specified in the Forensic Lucid language. We argue that self-forensics, with the forensics taken out of the cybercrime domain, is applicable to "self-dissection" of intelligent vehicles and hardware systems for automated incident and anomaly analys

Paulo Jose Oliveira Cortez, Jose Elias Tomazini, J. H. O. Sales, A. T. Suzuki

In this work we project and build an equipment for upper limb muscle strength assessment and we did some assays to measure it from volunteers.

Robert Beig, Bernd G. Schmidt

We construct solutions, for small values of $G$ and angular frequency $Ω$, of special relativistic scalar gravity coupled to ideally elastic matter which have helical but no stationary or axial symmetry. They correspond to a body without any symmetries in steady rotation around one of its axes of inertia, or two bodies moving on a circle around their center

J. Donnert, K. Dolag, G. Brunetti, R. Cassano

We use the results from a constrained, cosmological MHD simulation of the Local Universe to predict the radio halo and the gamma-ray flux from the Coma cluster and compare it to current observations. The simulated magnetic field within the Coma cluster is the result of turbulent amplification of the magnetic field during build-up of the cluster. The magnetic

V. D. Ivashchuk

A n-time generalization of Newton's law (of universal gravitation) formula in N =n + d + 1-dimensional space-time is conjectured. This formula implies a relation for effective N-dimensional gravitational constant G_{eff} = G cos^2 θ, where θis the angle between the direction of motion of two particles in n-dimensional time manifold R^n.

A. V. Afanasjev, H. Abusara

Time-odd mean fields (nuclear magnetism) are analyzed in the framework of covariant density functional theory (CDFT). It is shown that they always provide additional binding to the binding energies of odd-mass nuclei. This additional binding only weakly depends on the RMF parametrization reflecting good localization of the properties of time-odd mean fields

Jon C. Mauerhan, Schuyler D. Van Dyk, Pat W. Morris

We report new results from our effort to identify obscured Wolf-Rayet stars in the Galaxy. Candidates were selected by their near-infrared (2MASS) and mid-infrared (Spitzer/GLIMPSE) color excesses, which are consistent with free-free emission from ionized stellar winds and thermal excess from hot dust. We have confirmed 12 new Wolf-Rayet stars in the Galacti

Anthony Lee, Christopher Yau, Michael B. Giles, Arnaud Doucet

We present a case-study on the utility of graphics cards to perform massively parallel simulation of advanced Monte Carlo methods. Graphics cards, containing multiple Graphics Processing Units (GPUs), are self-contained parallel computational devices that can be housed in conventional desktop and laptop computers. For certain classes of Monte Carlo algorithm

Simeon Bird, Hiranya V. Peiris, Daniel Baumann

We investigate recent claims that brane inflation solves the overshoot problem through a combination of microphysical restrictions on the phase space of initial conditions and the existence of the Dirac-Born-Infeld (DBI) attractor in regimes where the slow-roll attractor does not apply. Carrying out a comprehensive analysis of the parameter space allowed by

Violet Poole, Guy Worthey, Hyun-chul Lee, Jedidiah Serven

Spectral feature index diagrams with integrated globular clusters and simple stellar population models often show that some clusters have weak H beta, so weak that even the oldest models cannot match the observed feature depths. In this work, we rule out the possibility that abundance mixture effects are responsible for the weak indices unless such changes o

Anthony J. C. Ladd, Rahul Kekre, Jason E. Butler

The aim of this paper is to compare results from lattice-Boltzmann and Brownian dynamics simulations of linear chain molecules. We have systematically varied the parameters that may affect the accuracy of the lattice-Boltzmann simulations, including grid resolution, temperature, polymer mass, and fluid viscosity. The effects of the periodic boundary conditio

D. Toussaint, W. Freeman

We calculate the &#34;strange quark content of the nucleon&#34;, <N| s s_bar |N>, which is important for interpreting the results of some dark matter detection experiments. The method is to evaluate quark-line disconnected correlations on the MILC lattice ensembles, which include the effects of dynamical strange quarks. After continuum and chiral extrapolati

Kfir Gedalyahu, Yonina C. Eldar

Time delay estimation arises in many applications in which a multipath medium has to be identified from pulses transmitted through the channel. Various approaches have been proposed in the literature to identify time delays introduced by multipath environments. However, these methods either operate on the analog received signal, or require high sampling rate

Alexander Barg, Oleg R. Musin

We derive a new estimate of the size of finite sets of points in metric spaces with few distances. The following applications are considered: (1) we improve the Ray-Chaudhuri--Wilson bound of the size of uniform intersecting families of subsets; (2) we refine the bound of Delsarte-Goethals-Seidel on the maximum size of spherical sets with few distances; (3)

J. Nichols, D. Dominko, L. Ladino, J. Zhou

We have studied the frequency and voltage dependence of voltage-induced torsional strains in orthorhombic TaS3 [V. Ya. Pokrovskii, et al, Phys. Rev. Lett. 98, 206404 (2007)] by measuring the modulation of the resonant frequency of an RF cavity containing the sample. The strain has an onset voltage below the charge-density-wave (CDW) threshold voltages associ

Yi Xie, Sergei Kopeikin

We construct a set of reference frames for description of the orbital and rotational motion of the Moon. We use a scalar-tensor theory of gravity depending on two parameters of the parametrized post-Newtonian (PPN) formalism and utilize the concepts of the relativistic resolutions on reference frames adopted by the International Astronomical Union in 2000. W

Mariam Bouhmadi-Lopez, Claus Kiefer, Barbara Sandhoefer, Paulo Vargas Moniz

Classical models for dark energy can exhibit a variety of singularities, many of which occur for scale factors much bigger than the Planck length. We address here the issue whether some of these singularities, the big freeze and the big demarrage, can be avoided in quantum cosmology. We use the framework of quantum geometrodynamics. We restrict our attention

Tobias Ahsendorf

In this article we define a minor relation, which is stronger than the classical one, but too strong to become a well-quasi-order on the class of finite graphs. Nevertheless, with this terminology we are able to introduce a conjecture, which would imply the Lovasz conjecture and give an interesting insight on the symmetry of vertex-transitive graphs, if true

Pawan Kumar, Rodolfo Barniol Duran

Observations of gamma-ray bursts by the Fermi satellite, capable of detecting photons in a very broad energy band: 8keV to >300GeV, have opened a new window for the study of these enigmatic explosions. It is widely assumed that photons of energy larger than 100 MeV are produced by the same source that generated lower energy photons -- at least whenever the s

Daniel Gottesman, Sandy Irani

We study the complexity of a class of problems involving satisfying constraints which remain the same under translations in one or more spatial directions. In this paper, we show hardness of a classical tiling problem on an N x N 2-dimensional grid and a quantum problem involving finding the ground state energy of a 1-dimensional quantum system of N particle

J. Martin Lindsay, Adam G. Skalski

Every Markov-regular quantum Levy process on a multiplier C*-bialgebra is shown to be equivalent to one governed by a quantum stochastic differential equation, and the generating functionals of norm-continuous convolution semigroups on a multiplier C*-bialgebra are then completely characterised. These results are achieved by extending the theory of quantum L

G. Catelani, Y. M. Xiong, X. S. Wu, P. W. Adams

We present a quantitative analysis of the low-temperature, high parallel field pairing resonance in ultra-thin superconducting Al films with dimensionless conductance g>>1. In this regime we derive an analytical expression for the tunneling density-of-states spectrum from which a variety of normal-state spin parameters can be extracted. We show that by fitti

Meng Zeng, Rui Zhang, Shuguang Cui

In wireless networks, communication links may be subject to random fatal impacts: for example, sensor networks under sudden power losses or cognitive radio networks with unpredictable primary user spectrum occupancy. Under such circumstances, it is critical to quantify how fast and reliably the information can be collected over attacked links. For a single p

Stijn Wuyts, Marijn Franx, Thomas J. Cox, Natascha M. Forster Schreiber

We present a comparison between the observed color distribution, number and mass density of massive galaxies at 1.5 < z < 3 and a model by Hopkins et al. that relates the quasar and galaxy population on the basis of gas-rich mergers. In order to test the hypothesis that quiescent red galaxies are formed after a gas-rich merger involving quasar activity, we c

Kurt Hinterbichler, Alberto Nicolis, Massimo Porrati

We reconsider the issue of superluminal propagation in the DGP model of infrared modified gravity. Superluminality was argued to exist in certain otherwise physical backgrounds by using a particular, physically relevant scaling limit of the theory. In this paper, we exhibit explicit five-dimensional solutions of the full theory that are stable against small

Benjamin Collie, David Tong

In both Yang-Mills theories and sigma models, instantons are endowed with degrees of freedom associated to their scale size and orientation. It has long been conjectured that these degrees of freedom have a dual interpretation as the positions of partonic constituents of the instanton. These conjectures are usually framed in d=3+1 and d=1+1 dimensions respec

Raj Gandhi, Pomita Ghoshal, Srubabati Goswami, S Uma Sankar

We examine the possibility of determining the neutrino mass hierarchy in the limit θ_{13} = 0 using atmospheric neutrinos as the source. In this limit, in which θ_{13} driven matter effects are absent, independent measurements of Δ_{31} and Δ_{32} can, in principle, lead to hierarchy determination. Since the difference between these two is Δ_{21}, one needs

Athanasios Chatzistavrakidis, George Zoupanos

Our aim is to derive the effective action in four dimensions resulting by reducing dimensionally the ten-dimensional ${\cal N}=1$ heterotic supergravity coupled to ${\cal N}=1$ super Yang-Mills over manifolds admitting a nearly-Kähler structure. Given the fact that all six-dimensional nearly-Kähler manifolds are included in the class of the corresponding non

Keiji Oguiso

We realize the logarithm of the third smallest known Salem number as the topological entropy of a K3 surface automorphism with a Siegel disk and a pointwisely fixed curve at the same time. We also show the logarithm of the Lehmer number, the smallest known Salem number, is not realizable as the topological entropy of any Enriques surface automorphism. These

Achaleshwar Sahai, Vaneet Aggarwal, Melda Yuksel, Ashutosh Sabharwal

In this paper, we study the effect of channel output feedback on the sum capacity in a two-user symmetric deterministic interference channel. We find that having a single feedback link from one of the receivers to its own transmitter results in the same sum capacity as having a total of 4 feedback links from both the receivers to both the transmitters. Hence

Samuel E. Gralla, Abraham I. Harte, Robert M. Wald

During the past century, there has been considerable discussion and analysis of the motion of a point charge, taking into account &#34;self-force&#34; effects due to the particle&#39;s own electromagnetic field. We analyze the issue of &#34;particle motion&#34; in classical electromagnetism in a rigorous and systematic way by considering a one-parameter fami

T. R. Cardoso, L. B. Castro, A. S. de Castro

Vector couplings in the Duffin-Kemmer-Petiau theory are revised. It is shown that minimal and nonminimal vector potentials behave differently under charge-conjugation and time-reversal transformations. In particular, it is shown that nonminimal vector potentials have been erroneously applied to the description of elastic meson-nucleus scatterings and that th

C. Bekh-Ochir, S. A. Rankin

We describe the T-ideal of identities and the T-space of central polynomials for the unitary finite dimensional Grassmann algebra over a finite field.

Joel Ratsaby

Let $|A|$ denote the cardinality of a finite set $A$. For any real number $x$ define $t(x)=x$ if $x\geq1$ and 1 otherwise. For any finite sets $A,B$ let $δ(A,B)$ $=$ $\log_{2}(t(|B\cap\bar{A}||A|))$. We define {This appears as Technical Report # arXiv:0905.2386v4. A shorter version appears in the {Proc. of Mini-Conference on Applied Theoretical Computer Scie

I. P. Sidelnik, B. Wundheiler, E. Colombo, A. Etchegoyen

AMIGA (Auger Muons and Infill for the Ground Array) constitutes an enhancement for the Pierre Auger Observatory. It consists of a denser array of surface detectors and muon counters whose objective is both to extend the detection range down to 10^17 eV and to help towards mass composition determination. The latter is to be achieved with muon counters since t

J. A. Aguilar-Saavedra

If new leptons exist close to the electroweak scale, they can be produced in pairs at LHC through standard or new interactions. We study the production of heavy lepton pairs in SM extensions with: (i) a Majorana or Dirac lepton triplet, as those appearing in type-III seesaw; (ii) a lepton isodoublet (N,E)_{L,R}; (iii) a charged isosinglet E_{L,R}; (iv) a Maj