July 2009 arXiv papers — page 28

Sławomir Stańczak, Michał Kaliszan, Nicholas Bambos

This paper deals with the problem of admission control/channel access in power-controlled decentralized wireless networks, in which the quality-of-service (QoS) is expressed in terms of the signal-to-interference ratio (SIR). We analyze a previously proposed admission control algorithm, which was designed to maintain the SIR of operational (active) links abo

Yael Karshon, Eugene Lerman

A key result in equivariant symplectic geometry is Delzant's classification of compact connected symplectic toric manifolds. The moment map induces an embedding of the quotient of the manifold by the torus action into the dual of the Lie algebra of the torus; its image is a unimodular ("Delzant") polytope; this gives a bijection between unimodula

Eduardo Balbinot, Basilio Santiago, Leandro Kerber, Batriz Barbuy

The LMC has a rich star cluster system spanning a wide range of ages and masses. One striking feature of the LMC cluster system is the existence of an age gap between 3-10 Gyrs. Four LMC clusters whose integrated colours are consistent with those of intermediate age simple stellar populations have been imaged with the Optical Imager (SOI) at the Southern Tel

E. Battaner, J. Castellano, M. Masip

The air-shower observatory Milagro has detected a large-scale anisotropy of unknown origin in the flux of TeV cosmic rays. We propose that this anisotropy is caused by galactic magnetic fields, in particular, that it results from the combined effects of the regular and the turbulent (fluctuating) magnetic fields in our vicinity. Instead of a diffusion equati

Scott Dodelson, Mika Vesterinen

Neutrinos decoupled from the rest of the cosmic plasma when the Universe was less than one second old, far earlier than the photons which decoupled at t=380,000 years. Surprisingly, though, the last scattering surface of the neutrinos is much closer to us than that of the photons. Here we calculate the properties of the last scattering surfaces of the three

Travis Dirks, Yung-Fu Chen, Norman O. Birge, Nadya Mason

We report results on superconducting tunneling spectroscopy of a carbon nanotube quantum dot. Using a three-probe technique that includes a superconducting tunnel probe, we map out changes in conductance due to band structure, excited states, and end-to-end bias. The superconducting probe allows us to observe enhanced spectroscopic features, such as robust s

Anthony R. Gorges, Mathew S. Hamilton, Jacob L. Roberts

We have studied the effects of loading $^{87}$Rb into a far off resonant trap (FORT) in the presence of an ultracold cloud of $^{85}$Rb. The presence of the $^{85}$Rb resulted in a marked decrease of the $^{87}$Rb load rate. This decrease is consistent with a decrease in the laser cooling efficiency needed for effective loading. While many dynamics which dis

Pasko Zupanovic, Milan Brumen, Ales Fajmut, Domagoj Kuic

We consider a thermodynamic state of a solvent and solution separated with an elastic semipermeable membrane in a box with a constant volume and the relevance of this simple model for the water uptake in tall trees. Under moderate concentrations of a solute, the solution and solvent are under the positive and negative pressure, respectively. In the case of t

Alexandru Chirvasitu

We provide examples of non-surjective epimorphisms $H\to K$ in the category of Hopf algebras over a field, even with the additional requirement that $K$ have bijective antipode, by showing that the universal map from a Hopf algebra to its enveloping Hopf algebra with bijective antipode is an epimorphism in $\halg$, although it is known that it need not be su

Nayaz Khalid Ahmed, Martin Hecht

A velocity boundary condition for the Lattice Boltzmann simulation technique has been proposed recently by Hecht and Harting[arxiv:0811.4593]. This boundary condition is independent of the relaxation process during collision and contains no artificial slip. In this work, this boundary condition is extended to simulate slip-flows. The extended boundary condit

Reem Yassawi

We study one-sided substitution subshifts, and how they can be represented using Bratteli-Vershik systems. In particular we focus on minimal recognizable substitutions such that the generated one-sided substitution subshift contains only one non-shift-invertible element (a branch point), and we call these substitutions quasi-invertible. We give an algorithm

R. B. Neufeld, B. Muller

The total energy deposited into the medium per unit length by a fast parton traversing a quark-gluon plasma is calculated. We take the medium excitation due to collisions to be given by the well known expression for the collisional drag force. The parton's radiative energy loss contributes to the energy deposition because each radiated gluon acts as an a

Longzhi Lin, Lu Wang

In this note we establish estimates for the harmonic map heat flow from $S^1$ into a closed manifold, and use it to construct sweepouts with the following good property: each curve in the tightened sweepout, whose energy is close to the maximal energy of curves in the sweepout, is itself close to a closed geodesic.

Stanislaw Drozdz, Jaroslaw Kwapien, Pawel Oswiecimka, Rafal Rak

Based on the Multifractal Detrended Fluctuation Analysis (MFDFA) and on the Wavelet Transform Modulus Maxima (WTMM) methods we investigate the origin of multifractality in the time series. Series fluctuating according to a qGaussian distribution, both uncorrelated and correlated in time, are used. For the uncorrelated series at the border (q=5/3) between the

A. Paggi, F. Massaro, V. Vittorini, A. Cavaliere

The synchrotron-self Compton (SSC) radiation process is widely held to provide a close representation of the double peaked spectral energy distributions from BL Lac Objects (BL Lacs), which are marked by non-thermal beamed radiations, highly variable on timescales of days or less. Their outbursts in the gamma ray relative to the optical/X rays might be surmi

Rodney Y. Sharp

In two recent papers, the author has developed a theory of graded annihilators of left modules over the Frobenius skew polynomial ring over a commutative Noetherian ring $R$ of prime characteristic $p$, and has shown that this theory is relevant to the theory of test elements in tight closure theory. One result of that work was that, if $R$ is local and the

S. Cupit-Foutou

A geometrical realization of wonderful varieties by means of a suitable class of invariant Hilbert schemes is given. As a consequence, Luna's conjecture asserting that wonderful varieties are classified by spherical systems, triples of combinatorial invariants, is proved.

Francesco Prino

The Inner Tracking System (ITS) is the detector of the ALICE central barrel located closest to the beam axis and it is therefore a key detector for tracking and vertexing performance. Here, the main results from the ITS commissioning with atmospheric muons in 2008 are presented, focusing in particular on the detector operation and calibration and on the meth

Jotsaroop K, S. Thangavelu

We study the boundedness of Toeplitz operators on Segal-Bargmann spaces in various contexts. Using Gutzmer's formula as the main tool we identify symbols for which the Toeplitz operators correspond to Fourier multipliers on the underlying groups. The spaces considered include Fock spaces, Hermite and twisted Bergman spaces and Segal-Bargmann spaces assoc

J. van den Berg

For ordinary (independent) percolation on a large class of lattices it is well known that below the critical percolation parameter $p_c$ the cluster size distribution has exponential decay and that power-law behavior of this distribution can only occur at $p_c$. This behavior is often called ``sharpness of the percolation transition.'' For theoretica

Paul Raff, Doron Zeilberger

One of the "deepest" theorems in mathematics is Endre Szemerédi's theorem about the inevitability of arithmetical progressions. Here we try to nibble at it, by doing "finite" analogs. This is already interesting for its own sake, but we believe that it has the potential to lead to extremely interesting sharpening of the currently rather w

Stefano Capitani, Johannes Weber, Hartmut Wittig

Minimally doubled fermions have been proposed as a cost-effective realization of chiral symmetry at non-zero lattice spacing. Using lattice perturbation theory at one loop, we study their renormalization properties. Specifically, we investigate the consequences of the breaking of hyper-cubic symmetry, which is a typical feature of this class of fermionic dis

A. K. Huettel, G. A. Steele, B. Witkamp, M. Poot

We have observed the transversal vibration mode of suspended carbon nanotubes at millikelvin temperatures by measuring the single-electron tunneling current. The suspended nanotubes are actuated contact-free by the radio frequency electric field of a nearby antenna; the mechanical resonance is detected in the time-averaged current through the nanotube. Sharp

Matej Pavsic

We investigate a reciprocally invariant system proposed by Low and Govaerts et al., whose action contains both the orthogonal and the symplectic forms and is invariant under global $O(2,4)\cap Sp(2,4)$ transformations. We find that the general solution to the classical equations of motion has no linear term in the evolution parameter, $τ$, but only the oscil

T. Shapoval, V. Metlushko, M. Wolf, B. Holzapfel

Strong pinning of superconducting flux quanta by a square array of 1 $μ$m-sized ferromagnetic dots in a magnetic-vortex state was visualized by low-temperature magnetic force microscopy (LT-MFM). A direct correlation of the superconducting flux lines with the positions of the dots was derived. The force that the MFM tip exerts on the individual vortex in the

Hao Wei

Since about ten years ago, varying $α$ theories attracted many attentions, mainly due to the first observational evidence from the quasar absorption spectra that the fine structure ``constant'' might change with cosmological time. In this work, we investigate the cosmic evolution of $α$ driven by the Dirac-Born-Infeld (DBI) scalar field. To be genera

Sakuntala Chatterjee, Gunter M. Schütz

Single-file diffusion of propane and toluene molecules inside a narrow, effectively one-dimensional zeolite pore was experimentally studied by Czaplewski {\sl et al.} Using a stochastic lattice gas approach, we obtain an analytical description of this process for the case of single-component loading. We show that a good quantitative agreement with the experi

Jaroslav Bielcik

A summary of the heavy flavor results from the STAR experiment is presented. Both open heavy flavor as well as quarkonia measurements are presented. A strong suppression of heavy flavor non-photonic electrons is observed in central Au+Au collisions at 200GeV. Relative contribution of bottom contribution to non-photonic electron spectra in p+p collisions is e

S. Sen, A. A. Sen, M. Sami

We consider different classes of scalar field models including quintessence, and tachyon scalar fields with a variety of generic potential belonging to thawing type. Assuming the scalar field is initially frozen at $w=-1$, we evolve the system until the present time. We focus on observational quantities like Hubble parameter, luminosity distance as well as q

Yurij Yaremko

Energy-momentum and angular momentum carried by electromagnetic field of two point-like charged particles arbitrarily moving in flat spacetime are presented. Apart from usual contributions to the Noether quantities produced separately by particles 1 and 2, the conservation laws contain also joint contribution due to the fields of both particles. The mixed pa

M. J. de la Puente

In this paper we fully describe all tropical linear mappings in the tropical projective plane, that is, maps from the tropical plane to itself given by tropical multiplication by an order 3 matrix. An erratum has been added fixing two mistakes in the main paper.

Takehito Yokoyama, Yukio Tanaka, Naoto Nagaosa

We investigate charge transport in two-dimensional ferromagnet/feromagnet junction on a topological insulator. The conductance across the interface depends sensitively on the directions of the magnetizations of the two ferromagnets, showing anomalous behaviors compared with the conventional spin-valve. It is found that the conductance depends strongly on the

Stefano Chesi, Daniel Loss, Sergey Bravyi, Barbara M. Terhal

We discuss and review several thermodynamic criteria that have been introduced to characterize the thermal stability of a self-correcting quantum memory. We first examine the use of symmetry-breaking fields in analyzing the properties of self-correcting quantum memories in the thermodynamic limit: we show that the thermal expectation values of all logical op

J. -N. Zhang, S. Yi

Under the framework of the semiclassical theory, we investigate the equilibrium-state properties of a spin polarized dipolar Fermi gas through full numerical calculation. We show that the Fermi surfaces in both real and momentum spaces are stretched along the attractive direction of dipolar interaction. We further verify that the deformed Fermi surfaces can

Yang Su

In this paper, we classify smooth 5-manifolds with fundamental group isomorphic to $\z/2$ and universal cover diffeomorphic to $S^2 \times S^3$. This gives a classification of smooth free involutions on $S^2 \times S^3$ up to conjugation.

The CERES Collaboration

This paper has been withdrawn by the authors because the formula used to fit the pion source radii accounted for only one of the two effects of finite viscosity, and because a mistake in interpreting RHIC data was discovered.

Harvendra Singh

This work is based on an earlier proposal \cite{hs} that the membrane B-F theory consists of matter fields alongwith Chern-Simons fields as well as the auxiliary pairs of scalar and tensor fields. We especially discuss the supersymmetry aspects of such a membrane theory. It is concluded that the theory possesses maximal supersymmetry and it is related to the

Jan de Boer, Kyriakos Papadodimas, Erik Verlinde

We construct in the context of the AdS/CFT correspondence degenerate composite operators in the conformal field theory that are holographically dual to degenerate stars in anti de Sitter space. We calculate the effect of the gravitational back-reaction using the Tolman-Oppenheimer-Volkoff equations, and determine the "Chandrasekhar limit" beyond whic

Hirotaka Yoshino, Masaru Shibata

We derive a formalism of numerical relativity for higher-dimensional spacetimes and develop numerical codes for simulating a wide variety of five-dimensional (5D) spacetimes for the first time. First, the Baumgarte-Shapiro-Shibata-Nakamura formalism is extended for arbitrary spacetime dimensions $D \ge 4$, and then, the so-called cartoon method, which was or

N. Dupuis

In a Bose superfluid, the coupling between transverse (phase) and longitudinal fluctuations leads to a divergence of the longitudinal correlation function, which is responsible for the occurrence of infrared divergences in the perturbation theory and the breakdown of the Bogoliubov approximation. We report a non-perturbative renormalization-group (NPRG) calc

A. Cristea, G. Gonnella, A. Lamura, V. Sofonea

Phase separation of a two-dimensional van der Waals fluid subject to a gravitational force is studied by numerical simulations based on lattice Boltzmann methods (LBM) implemented with a finite difference scheme. A growth exponent $\alpha=1$ is measured in the direction of the external force.

Youichi Yanase, Manfred Sigrist

The antiferromagnetic Fulde-Ferrell-Larkin-Ovchinnikov (AFM-FFLO) state of coexisting d-wave FFLO superconductivity and incommensurate AFM order is studied on the basis of Bogoliubov-de Gennes (BdG) equations. We show that the incommensurate AFM order is stabilized in the FFLO state by the appearance of the Andreev bound state localized around the zeros of t

Lizhen Xu, Radu V. Craiu, Lei Sun

Parameter estimates for associated genetic variants, report ed in the initial discovery samples, are often grossly inflated compared to the values observed in the follow-up replication samples. This type of bias is a consequence of the sequential procedure in which the estimated effect of an associated genetic marker must first pass a stringent significance

Aloys Krieg, Martin Raum

We prove the functional equation for the twisted spinor L-series of a cuspidal, holomorphic Siegel eigenform for the full modular group of genus 2. It follows from a more general functional equation, valid for Rankin convolutions of paramodular cuspforms. A non-vanishing result for Fourier-Jacabi coefficients of the eigenforms in question is the central pill

Tim Netzer

Spectrahedra are sets defined by linear matrix inequalities. Projections of spectrahedra are called semidefinitely representable sets. Both kinds of sets are of practical use in polynomial optimization, since they occur as feasible sets in semidefinite programming. There are several recent results on the question which sets are semidefinite representable. So

Martin Raum

We develop an elementary divisor theory for the unimodular and the modular group over quadratic field extensions and quaternion algebras. In particular, we investigate which sets of elementary divisors can occur. Under an additional hypothesis we establish a correspondence of unimodular and modular double cosets.

L. Tiemann, Y. Yoon, W. Dietsche, K. von Klitzing

We will discuss the relevant conditions to observe a critical tunneling current [New J. Phys. 10, 045018 (2008)] in electron double-layer systems at a total filling factor of 1 and find they are related to the effective layer separation and the temperature. Our studies suggest that the intensity of the critical tunneling behavior is also directly linked to t

A. N. Trahtman, T. Bauer, N. Cohen

A synchronizing word of a deterministic automaton is a word in the alphabet of colors of its edges that maps the automaton to a single state. A coloring of edges of a directed graph is synchronizing if the coloring turns the graph into a deterministic finite automaton possessing a synchronizing word. The road coloring problem is the problem of synchronizing

Jorge L. Nisperuza, Luis A. Sanchez

Flavour changing neutral currents arise in the $SU(3)_c\otimes SU(4)_L\otimes U(1)_X$ extension of the standard model because anomaly cancellation among the fermion families requires one generation of quarks to transform differently from the other two under the gauge group. In the weak basis the distinction between quark families is meaningless. However, in

Ishanu Chattopadhyay, Asok Ray

Decision processes with incomplete state feedback have been traditionally modeled as Partially Observable Markov Decision Processes. In this paper, we present an alternative formulation based on probabilistic regular languages. The proposed approach generalizes the recently reported work on language measure theoretic optimal control for perfectly observable

Emiko Arahata, Tetsuro Nikuni

We study sound propagation in a uniform superfluid gas of Fermi atoms in the unitary limit. The existence of normal and superfluid components leads to appearance of two sound modes in the collisional regime, referred to as first and second sound. The second sound is of particular interest as it is a clear signal of a superfluid component. Using Landau's

Xiao-Gang He, Ernest Ma

The seesaw mechanism for three neutrinos is discussed, clarifying the situation where the seesaw texture results in three approximately zero mass eigenvalues. The true underlying mechanism is shown to be just the $inverse$ (or $linear$) seesaw, which explains why there could be large mixing. However, these zeroes cannot occur naturally, unless there is a con

Zhenfei Liu, Kieron Burke

Modern density functional theory (DFT) calculations employ the Kohn-Sham (KS) system of non-interacting electrons as a reference, with all complications buried in the exchange-correlation energy (Exc). The adiabatic connection formula gives an exact expression for Exc. We consider DFT calculations that instead employ a reference of strictly-correlated electr

Hao Liu, Ti-Pei Li

The cosmic microwave background (CMB) temperature maps published by the Wilkinson Microwave Anisotropy Probe (WMAP) team are found to be inconsistent with the differential time-ordered data (TOD), from which the maps are reconstructed. The inconsistency indicates that there is a serious problem in the map making routine of the WMAP team, and it is necessary

Nengkun Yu, Runyao Duan, Mingsheng Ying

A $2\otimes 2$ unitary operation is called a perfect entangler if it can generate a maximally entangled state from some unentangled input. We study the following question: How many runs of a given two-qubit entangling unitary operation is required to simulate some perfect entangler with one-qubit unitary operations as free resources? We completely solve this

Robert K. Niven, Bjarne Andresen

The set of solutions inferred by the generic maximum entropy (MaxEnt) or maximum relative entropy (MaxREnt) principles of Jaynes - considered as a function of the moment constraints or their conjugate Lagrangian multipliers - is endowed with a Riemannian geometric description, based on the second differential tensor of the entropy or its Legendre transform (

Stephan Ramon Garcia, Levon Balayan

We develop several methods, based on the geometric relationship between the eigenspaces of a matrix and its adjoint, for determining whether a square matrix having distinct eigenvalues is unitarily equivalent to a complex symmetric matrix. Equivalently, we characterize those matrices having distinct eigenvalues which lie in the unitary orbit of the complex s

D. Peressounko, Y. Kharlov

We give an overview of photon physics which will be studied by the ALICE experiment in proton-proton and heavy ion collisions at LHC. We compare properties of ALICE photon detectors and estimate their ability to measure neutral meson and direct photon spectra as well as gamma-hadron and gamma-jet correlations in pp and Pb+Pb collisions.

Shin-Shan Yu

This document reviews several recent measurements at the Fermilab Tevatron, including the cross sections of inclusive jet, dijet production, the cross sections of electroweak boson (W or Z) production in association with inclusive or heavy-flavor (b or c) jets, and b-jet shapes. In addition, searches for new physics using the dijet angular distributions are

Pierre Marage

Recent results on Deeply Virtual Compton Scattering (DVCS) and exclusive vector meson (VM) production obtained with the H1 detector at HERA are reviewed. Emphasis is put on the transition from soft to hard diffraction and on spin dynamics.

Chiranjeeb Buragohain, Luca Foschini, Subhash Suri

Monitoring the performance of large shared computing systems such as the cloud computing infrastructure raises many challenging algorithmic problems. One common problem is to track users with the largest deviation from the norm (outliers), for some measure of performance. Taking a stream-computing perspective, we can think of each user's performance prof

O. Corradini, P. Faccioli, H. Orland

We present a novel approach to investigate the long-time stochastic dynamics of multi-dimensional classical systems, in contact with a heat-bath. When the potential energy landscape is rugged, the kinetics displays a decoupling of short and long time scales and both Molecular Dynamics (MD) or Monte Carlo (MC) simulations are generally inefficient. Using a fi

D. Cruz-Uribe, C. Rios

We prove the Kato conjecture for degenerate elliptic operators in R^n. More precisely, we consider the divergence form operator L_w = -1/w div (wA) grad, where w is a Muckenhoupt A_2 weight and A is a complex valued n x n matrix which is bounded and uniformly elliptic. We show that if the associated semigroup satisfies Gaussian upper bounds, then the Kato sq

Younghee Kim, Seog-Hoon Rim, Byungje Lee, Taekyun Kim

The purpose of this paper is to derive some identities of the higher order generalized twisted Bernoulli numbers and polynomials attached to $χ$ from the properties of the p-adic invariant integrals.

Jessie Rosenberg, Rajeev V. Shenoi, Thomas E. Vandervelde, Sanjay Krishna

We demonstrate a multi-spectral polarization sensitive mid-infrared dots-in-a-well (DWELL) photodetector utilizing surface-plasmonic resonant elements, with tailorable frequency response and polarization selectivity. The resonant responsivity of the surface-plasmon detector shows an enhancement of up to 5 times that of an unpatterned control detector. As the

A. Badertscher, L. Knecht, M. Laffranchi, D. Lussi

We constructed and operated a double phase (liquid-vapour) pure argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC) with a sensitive area of 10x10 cm$^2$ and up to 30 cm of drift length. The LEM is a macroscopic hole electron multiplier built with standard PCB techniques: drifting electrons are extracted from the liquid to the vapour phase

J. King, A. Kupferthaler, K. Unterkofler, H. Koc

A real-time recording setup combining exhaled breath VOC measurements by proton transfer reaction mass spectrometry (PTR-MS) with hemodynamic and respiratory data is presented. Continuous automatic sampling of exhaled breath is implemented on the basis of measured respiratory flow: a flow-controlled shutter mechanism guarantees that only end-tidal exhalation

Joaquim Prades

I review the recent calculations and current status of the hadronic light-by-light scattering contribution to muon g-2. In particular, I discuss the main results obtained in a recent work together with Eduardo de Rafael and Arkady Vainshtein where we came to the estimate a^{\rm HLbL}_μ= (10.5 +- 2.6) x 10^{-10}. How the two-photon physics program of low ener

O. Mosendz, G. Mihailovic, J. E. Pearson, P. Fischer

We investigated Co/Cu lateral spin valves by means of high-resolution transmission soft x-ray microscopy with magnetic contrast that utilizes x-ray magnetic circular dichroism (XMCD). No magnetic XMCD contrast was observed at the Cu L$_3$ absorption edge, which should directly image the spin accumulation in Cu. Although electrical transport measurements in a

Sergey L. Bud'ko, Ni Ni, Paul C. Canfield

We report anisotropic thermal expansion of the parent, AEFe2As2 (AE = Ba, Sr, and Ca), compounds. Above the structural/antiferromagnetic phase transition anisotropy of the thermal expansion coefficients is observed, with the coefficient along the a-axis being significantly smaller than the coefficient for the c-axis. The high temperature (200 K < T < 300 K)

Marcus Pivato

A `symbolic dynamical system&#39; is a continuous transformation F:X-->X of a closed perfect subset X of A^V, where A is a finite set and V is countable. (Examples include subshifts, odometers, cellular automata, and automaton networks.) The function F induces a directed graph structure on V, whose geometry reveals information about the dynamical system (X,F

Agnieszka Ruebenbauer

The animals, in particular insects (Drosophila melanogaster), response towards odor stimuli in nature can be established by measuring the dynamic of the odor response. Such an approach is innovative since responses to odors were tested only at certain time point so far, not in hour intervals for several hours. The odor attraction to 14 natural and ecological

Eliza Miller-Ricci, Michael R. Meyer, Sara Seager, Linda Elkins-Tanton

We explore the appearance of terrestrial planets in formation by studying the emergent spectra of hot molten protoplanets during their collisional formation. While such collisions are rare, the surfaces of these bodies may remain hot at temperatures of 1000-3000 K for up to millions of years during the epoch of their formation. These object are luminous enou

R. G. Detmers, J. S. Kaastra, I. M. McHardy

We study the long time scale variability of the gas responsible for the X-ray narrow emission lines in the Seyfert 1 galaxy NGC 5548, in order to constrain the location and geometry of the emitting gas. Using X-ray spectra taken with the Chandra-LETGS and HETGS instruments and with XMM-Newton RGS and combining them with long-term monitoring observations of t

Hassan Gobjuka

With the major wireless service providers planning to start deployment of 4G wireless networks by mid 2010, research and industry communities are racing against time to find solutions for some of the prominent still open issues in 4G networks. The growing interest in 4G networks is driven by the set of new services will be made available for the first time s

Wen-Jun Hu, Ning-Hua Tong

The dynamical mean field theory (DMFT), which is successful in the study of strongly correlated fermions, was recently extended to boson systems [Phys. Rev. B {\textbf 77}, 235106 (2008)]. In this paper, we employ the bosonic DMFT to study the Bose-Hubbard model which describes on-site interacting bosons in a lattice. Using exact diagonalization as the impur

M. Viel, J. S. Bolton, M. G. Haehnelt

We use the probability distribution function (PDF) of the lya forest flux at z=2-3, measured from high-resolution UVES/VLT data, and hydrodynamical simulations to obtain constraints on cosmological parameters and the thermal state of the intergalactic medium (IGM) at z 2-3. The observed flux PDF at z=3 alone results in constraints on cosmological parameters

Manuel Bodirsky, Markus Junker

We extend the Ahlbrandt--Ziegler analysis of interpretability in aleph_0-categorical structures by showing that existential interpretation is controlled by the monoid of self--embeddings and positive existential interpretation of structures without constant endomorphisms is controlled by the monoid of endomorphisms in the same way as general interpretability

Shun Saito, Masahiro Takada, Atsushi Taruya

Future or ongoing galaxy redshift surveys can put stringent constraints on neutrinos masses via the high-precision measurements of galaxy power spectrum, when combined with cosmic microwave background (CMB) information. In this paper we develop a method to model galaxy power spectrum in the weakly nonlinear regime for a mixed dark matter (CDM plus finite-mas

Matthew J. Turk, Tom Abel, Brian W. O&#39;Shea

Previous high resolution cosmological simulations predict the first stars to appear in the early universe to be very massive and to form in isolation. Here we discuss a cosmological simulation in which the central 50 solar mass clump breaks up into two cores, having a mass ratio of two to one, with one fragment collapsing to densities of 10^{-8} g/cc. The se

Richard H. Cyburt, Sam M. Austin, Timothy C. Beers, Alfredo Estrade

The research area of nuclear astrophysics is characterized by a need for information published in tens of journals in several fields and an extremely dilute distribution of researchers. For these reasons it is difficult for researchers, especially students, to be adequately informed of the relevant published research. For example, the commonly employed journ

Guangyong Xu

Neutron and x-ray scattering studies on relaxor ferroelectric systems Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_3$ (PZN), Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$ (PMN), and their solid solutions with PbTiO$_3$ (PT) have shown that inhomogeneities and disorder play important roles in the materials properties. Although a long-range polar order can be established at low temperature - s

Z. C. Feng, Y. Charles Li

Flux dynamics in an annular long Josephson junction is studied. Three main topics are covered. The first is chaotic flux dynamics and its prediction via Melnikov integrals. It turns out that DC current bias cannot induce chaotic flux dynamics, while AC current bias can. The existence of a common root to the Melnikov integrals is a necessary condition for the

C. Carbone, M. Veronese, P. Moras, S. Gardonio

High-resolution photoemission spectroscopy and realistic ab-initio calculations have been employed to analyze the onset and progression of d-sp hybridization in Fe impurities deposited on alkali metal films. The interplay between delocalization, mediated by the free-electron environment, and Coulomb interaction among d-electrons gives rise to complex electro

Qiang Zhen, Charles Knessl

We consider the $M/M/1$ queue with processor sharing. We study the conditional sojourn time distribution, conditioned on the customer&#39;s service requirement, in various asymptotic limits. These include large time and/or large service request, and heavy traffic, where the arrival rate is only slightly less than the service rate. The asymptotic formulas rel

Mrs. T. Theivasanthi

Chaos is an active research subject in the fields of science in recent years. it is a complex and an erratic behavior that is possible in very simple systems. in the present day, the chaotic behavior can be observed in experiments. Many studies have been made in chaotic dynamics during the past three decades and many simple chaotic systems have been discover

Qiang Zhen, Charles Knessl

We consider a processor shared $M/M/1$ queue that can accommodate at most a finite number $K$ of customers. We give an exact expression for the sojourn time distribution in the finite capacity model, in terms of a Laplace transform. We then give the tail behavior, for the limit $K\to\infty$, by locating the dominant singularity of the Laplace transform.

N. Kevlahan, Ralph E. Pudritz

The main observational evidence for turbulence in the interstellar medium (ISM) and molecular clouds is the power-law energy spectrum for velocity fluctuations, E(k) \propto k^α. The Kolmogorov scaling exponent, α=-5/3, is typical. At the same time, the observed probability distribution function (PDF) of gas densities in both the ISM as well as in molecular

A. V. Kuznetsov, N. V. Mikheev, A. A. Okrugin

The neutrino helicity-flip process under the conditions of the supernova core is reinvestigated. Instead of the uniform ball model for the SN core used in previous analyses, realistic models for radial distributions and time evolution of physical parameters in the SN core are considered. A new upper bound on the Dirac neutrino magnetic moment is obtained fro

David G. Turner, V. V. Kovtyukh, Daniel J. Majaess, David J. Lane

New and existing photometry for the G0 Ia supergiant HD 18391 is analyzed in order to confirm the nature of the variablity previously detected in the star, which lies off the hot edge of the Cepheid instability strip. Small-amplitude variability at a level of ΔV = 0.016+-0.002 is indicated, with a period of P=123.04+-0.06 d. A weaker second signal may be pre

L. Gaudreau, A. Kam, P. Zawadzki, G. Granger

Telegraphic noise is one of the most significant problems that arises when making sensitive measurements with lateral electrostatic devices. In this paper we demonstrate that a wafer which had only produced devices with significant telegraph noise problems can be made to produce &#39;quiet&#39; devices if a thin insulator layer is placed between the gates an

A. V. Chumak, P. Dhagat, A. Jander, A. A. Serga

We report on the observation of reverse Doppler effect in backward spin waves reflected off of surface acoustic waves. The spin waves are excited in a yttrium iron garnet (YIG) film. Simultaneously, acoustic waves are also generated. The strain induced by the acoustic waves in the magnetostrictive YIG film results in the periodic modulation of the magnetic a

R. F. Gabbasov, M. A. Rodriguez-Meza, J. L. Cervantes-Cota, J. Klapp

We study bar formation in galactic disks as a consequence of the collision of two spiral galaxies under the influence of a potential which is obtained from the Newtonian limit of a scalar--tensor theory of gravity. We found that dynamical effects depend on parameters ($α$, $λ$) of the theory. In particular, we observe that the bar is shorter for weaker tidal

M. A. Rodriguez-Meza

We present numerical $N$-body simulation studies of large-scale structure formation. The main purpose of these studies is to analyze the several models of dark matter and the role they played in the process of large-scale structure formation. We analyze the standard and more successful case, i.e., the cold dark matter with cosmological constant ($Λ$CDM). We

Frédéric Grosshans

We show that replacing the usual sifting step of the standard quantum-key-distribution protocol BB84 by a one-way reverse reconciliation procedure increases its robustness against photon-number-splitting (PNS) attacks to the level of the SARG04 protocol while keeping the raw key-rate of BB84. This protocol, which uses the same state and detection than BB84,

Angelo Loinger, Tiziana Marsico

By virtue of Hilbert repulsive effect, the most external singular surface of Reissner-Weyl-Nordstroem metric represents an insuperable barrier for the arriving neutral particles and light rays.

Olivier Xeridat, Charles Poli, Olivier Legrand, Fabrice Mortessagne

We report non-invasive measurements of the complex field of elastic quasimodes of a silicon wafer with chaotic shape. The amplitude and phase spatial distribution of the flexural modes are directly obtained by Fourier transform of time measurements. We investigate the crossover from real mode to complex-valued quasimode, when absorption is progressively incr

Annica M. Black-Schaffer, Sebastian Doniach

While not widely recognized, electronic correlations might play an important role in graphene. Indeed, Pauling&#39;s resonance valence bond (RVB) theory for the pp-bonded planar organic molecules, of which graphene is the infinite extension, already established the importance of the nearest neighbor spin-singlet bond (SB) state in these materials. However, d

Lior Bary-Soroker

This PhD deals with the notion of pseudo algebraically closed (PAC) extensions of fields. It develops a group-theoretic machinery, based on a generalization of embedding problems, to study these extensions. Perhaps the main result is that although there are many PAC extensions, the Galois closure of a proper PAC extension is separably closed. The dissertatio

Gyu-Boong Jo, Ye-Ryoung Lee, Jae-Hoon Choi, Caleb A. Christensen

Can a gas of spin-up and spin-down fermions become ferromagnetic due to repulsive interactions? This question which has not yet found a definitive theoretical answer was addressed in an experiment with an ultracold two-component Fermi gas. The observation of non-monotonic behavior of lifetime, kinetic energy, and size for increasing repulsive interactions pr