January 2006 arXiv papers — page 11

H. Witala, J. Golak, R. Skibinski, W. Glockle

The proton to proton polarization transfer coefficients K_x^{x'}, K_y^{y'}, K_z^{x'} and the proton to deuteron polarization transfer coefficients K_x^{x'}, K_y^{y'}, K_z^{x'}, K_x^{y'z'}, K_y^{z'z'}, K_z^{y'z'}, K_y^{x'z'} and K_y^{x'x'-y'y'} have been measured in d(\vec p, \vec p)d and

M. Kaskulov, L. Roca, E. Oset

Using results of a recent calculation of the $Λ(1520)$ in the nuclear medium, which show that the medium width is about five times the free width, we study the A dependence of the $Λ(1520)$ production cross section in the reactions $γ~A \to K^+ Λ(1520) A^\prime$ and $p~ A \to p~ K^+ Λ(1520) A^\prime$. We find a sizable A dependence in the ratio of the nuclea

Lukas Jahnke, Stefan Leupold

A relativistic description of spin 3/2 resonances and their decay channels is presented by calculating their selfenergies and spectral functions. The full vector-spinor structure is taken into account. Special emphasis is put on the N*(1520) and its decay channels pi N, rho N and pi Δ. All interactions are formulated such that only the correct number of degr

A. Hoell, C. D. Roberts, S. V. Wright

Detailed investigations of the structure of hadrons are essential for understanding how matter is constructed from the quarks and gluons of QCD, and amongst the questions posed to modern hadron physics, three stand out. What is the rigorous, quantitative mechanism responsible for confinement? What is the connection between confinement and dynamical chiral sy

D. S. Delion, R. J. Liotta, R. Wyss

A very simple formula is presented that relates the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The corresponding experimental data lie on two straight lines which appear as a result of a sudden change in the nuclear shape marking two regions of deformation independently of the angul

T. Sato, B. Szczerbinska, K. Kubodera, T. -S. H. Lee

In this report, we will briefly review the dynamical model of pion electroweak production reactions in the $Δ$ resonance region and report on our study of neutrino-nucleus reactions based on this model.

A. Haga, H. Toki, S. Tamenaga, Y. Horikawa

The isoscalar and isovector collective multipole excitations in stable nuclei are studied in the framework of relativistic random-phase approximation with the vacuum polarization arising from the nucleon-antinucleon field. A fully self-consistent calculation which guarantees the decoupling of the spurious state and the conservation of the multipole-transitio

Yu. T. Kiselev, E. Ya. Paryev

We present the analysis of experimental data on forward antiproton production on nuclei. The calculations are done in the framework of a folding model which takes properly into account both incoherent direct proton-nucleon and cascade pion-nucleon antiproton production processes as well as internal nucleon momentum distribution. The effective antiproton-nucl

A. N. Sissakian, A. S. Sorin, M. K. Suleymanov, V. D. Toneev

Available experimental data in respect to a possible formation of a strongly interacting mixed phase are outlined. A physical program is formulated for new facilities being opend in Dubna for acceleration of heavy ions with an energy up to 5 AGeV.

Narcisse Zahibo, Irina Didenkulova, Andrey Kurkin, Efim Pelinovsky

Process of the nonlinear deformation of the shallow water wave in a basin of constant depth is studied. The characteristics of the first breaking are analyzed in details. The Fourier spectrum and steepness of the nonlinear wave is calculated. It is shown that spectral amplitudes can be expressed through the wave front steepness, and this can be used for prac

Claude Roger, Jeremie Unterberger

This article is concerned with an extensive study of an infinite-dimensional Lie algebra $\mathfrak{sv}$, introduced in the context of non-equilibrium statistical physics, containing as subalgebras both the Lie algebra of invariance of the free Schrödinger equation and the central charge-free Virasoro algebra $Vect(S^1)$. We call $\mathfrak{sv}$ the Schrödin

K. T. -R. McLaughlin, A. H. Vartanian, X. Zhou

Let $Λ^{\mathbb{R}}$ denote the linear space over $\mathbb{R}$ spanned by $z^{k}$, $k \in \mathbb{Z}$. Define the real inner product (with varying exponential weights) $<\boldsymbol{\cdot},\boldsymbol{\cdot} >_{\mathscr{L}} \colon Λ^{\mathbb{R}} \times Λ^{\mathbb{R}} \to \mathbb{R}$, $(f,g) \mapsto \int_{\mathbb{R}}f(s)g(s) \exp (-\mathscr{N} V(s)) \md s$, $

Allan Sinclair, Roger Smith, Stuart White, Alan Wiggins

A singular masa $A$ in a $\rm{II}_{1}$ factor $N$ is defined by the property that any unitary $w\in N$ for which $A=wAw^*$ must lie in $A$. A strongly singular masa $A$ is one that satisfies the inequality $$\| E_A- E_{wAw^*}\|_{\infty,2}\geq\|w- E_A(w)\|_2$$ for all unitaries $w\in N$, where $E_A$ is the conditional expectation of $N$ onto $A$, and $\|\cdot

Qi S. Zhang

We introduce some new classes of time dependent functions whose defining properties take into account of oscillations around singularities. We study properties of solutions to the heat equation with coefficients in these classes which are much more singular than those allowed under the current theory. In the case of $L^2$ potentials and $L^2$ solutions, we g

M. Neamtu, D. Opris, R. F. Horhat

The objective of this paper is to investigate the stability of limit cycles of a mathematical model with a distributed delay which describes the interaction between p53 and mdm2. Choosing the delay as a bifurcation parameter we study the direction and stability of the bifurcating periodic solutions using the normal form and the center manifold theorem. Some

Colette Anné

We give a definition of the Maslov fibre bundle for a lagrangian submanifold of the cotangent bundle of a smooth manofold. This definition generelizes the definition given, in homotopic terms, by Arnol&#39;d for lagrangian submanifolds of the cotangent bundle of the euclidean space and coincides with the one of Hörmander in his works about Fourier Inegral Op

George P. Yanev, Ljuben Mutafchiev

We associate with a Bienayme-Galton-Watson branching process a family tree rooted at the ancestor. For a positive integer N, define a complete N-ary tree to be the family tree of a deterministic branching process with offspring generating function s^N. We study the random variables V(N,n) and V(N) counting the number of disjoint complete N-ary subtrees, root

Rodrigo Ristow Montes Jose Antonio Verderesi

In this paper we introduce the notion of contact angle for an immersed surface in three dimensional sphere. We deduce formulas for the Laplacian and for the Gaussian curvature, and we classify minimal surfaces in $S^3$ with constant contact angle. Also, we give an example of a minimal surface in $S^3$ with non constant contact angle.

G. Pacelli Bessa, L. Jorge, J. Fabio Montenegro

We show that a complete $m$-dimensional immersed submanifold $M$ of $\mathbb{R}^{n}$ with $a(M)<1$ is properly immersed and have finite topology, where $a(M)\in [0,\infty]$ is an scaling invariant number that gives the rate that the norm of the second fundamental form decays to zero at infinity. The class of submanifolds $M$ with $a(M)<1$ contains all comple

Ganna Kudryavtseva, Victor Maltcev

We construct a family of representations of an arbitrary variant $S_a$ of a semigroup $S$, induced by a given representation of $S$, and investigate properties of such representations and their kernels.

Matthew Grime

We examine various triangulated quotients of the module category of a finite group. We demonstrate that these are not compactly generated by the simple modules and present a modification of Rickard&#39;s Idempotent Module construction that accounts for this. When the localizing subcategories are sufficiently nice we give an explicit description of the object

Colette Moeglin

The goal of this paper is to prove how Arthur&#39;s results, in the case of split odd orthogonal p-adic groups, imply the Langlands&#39; classification of discrete series. Of course this need the validity of &#39;&#39;fundamental&#39;&#39; lemmas which are not yet available. And this include a Langlands&#39; classification of cuspidal irreducible representat

H. Gopalkrishna Gadiyar, R. Padma

Currently the circle and the sieve methods are the key tools in analytic number theory. In this paper the unifying theme of the two methods is shown to be the Ramanujan - Fourier series.

Lev Idels, Mei Wang

In traditional harvesting model a fishing effort E is defined by the fishing intensity and does not address the inverse effect of fish abundance on the fishing effort. In this paper, based on a canonical differential equation model, we developed a new fishing effort model which relies on the density effect of fish population. We obtained new differential equ

Ljuben Mutafchiev, Emil Kamenov

The paper presents a discussion on the asymptotic formula for the number of plane partitions of a large positive integer.

Mathieu Sablik

Let $(\az,F)$ be a bipermutative algebraic cellular automaton. We present conditions which force a probability measure which is invariant for the $\N\times\Z$-action of $F$ and the shift map $\s$ to be the Haar measure on $\gs$, a closed shift-invariant subgroup of the Abelian compact group $\az$. This generalizes simultaneously results of B. Host, A. Maass

Wael Abu-Shammala, Ji-Liang Shiu, Alberto Torchinsky

We describe the spaces $H^1(R)$ and BMO$(R)$ in terms of their closely related, simpler dyadic and two-sided counterparts. As a result of these characterizations we establish when a bounded linear operator defined on dyadic or two-sided $H^1(R)$ into a Banach space has a continuous extension to $H^1(R)$ and when a bounded linear operator that maps a Banach s

Ji-Young Ham, Won Taek Song

The minimum dilatation of pseudo-Anosov 5-braids is shown to be the largest zero $λ_5 \approx 1.72208$ of $x^4 - x^3 - x^2 - x + 1$ which is attained by $σ_1σ_2σ_3σ_4σ_1σ_2$.

Daniel Maerten

This paper proves a positive energy-momentum theorem for oriented Riemannian 3-manifolds that are asymptotic to a standard hyperbolic slice in anti de Sitter space-time. Analogously to the original Witten&#39;s proof in the asymptotically flat case, this result relies on spinorial methods. We also give a rigidity theorem: if the energy-momentum is degenerate

A. Shutov, H. Altenbach, K. Naumenko

The stress analysis of pressurized circumferential pipe weldments under steady state creep is considered. The creep response of the material is governed by Norton&#39;s law. Numerical and analytical solutions are obtained by means of perturbation method, the unperturbed solution corresponds to the stress field in a homogeneous pipe. The correction terms are

Charles Favre, Juan Rivera-Letelier

We introduce a new class of adelic heights on the projective line. We estimate their essential minimum and prove a result of equidistribution (at every place) for points of small height with estimates on the speed of convergence. To each rational function R in one variable and defined over a number field K, is associated a normalized height on the algebraic

Antar Bandyopadhyay

This paper has been withdrawn by the author because of finding a flaw in the proof of endogeny for the Frozen Percolation RDE which was one of two examples discussed in this paper. The other example is correct and can be obtained from the work &#34;Bivariate Uniqueness and Endogeny for the Logistic Recursive Distributional Equation&#34; of the author. At the

William F. Rulla

Let X_n := \bar M_{0,n}, the moduli space of n-pointed stable genus zero curves, and let X_{n,m} be the quotient of X_n by the action of the symmetric group S_{n-m} on the last n-m marked points. The cones of effective divisors of X_{n,m}, m = 0,1,2, are calculated. Using this, upper bounds for the cones Mov(X_{n,m}) generated by divisors with moving linear

Jeremy L. Martin

Let $m_{12}$, $m_{13}$, ..., $m_{n-1,n}$ be the slopes of the $\binom{n}{2}$ lines connecting $n$ points in general position in the plane. The ideal $I_n$ of all algebraic relations among the $m_{ij}$ defines a configuration space called the {\em slope variety of the complete graph}. We prove that $I_n$ is reduced and Cohen-Macaulay, give an explicit Gröbner

Giuseppe Bimonte, Enrico Calloni, Giampiero Esposito, Luigi Rosa

We study the influence of Casimir energy on the critical field of a superconducting film, and we show that by this means it might be possible to directly measure, for the first time, the variation of Casimir energy that accompanies the superconducting transition. It is shown that this novel approach may also help clarifying the long-standing controversy on t

Taro Kashiwa, Tomohiko Sakaguchi

A study for checking validity of the auxiliary field method (AFM) is made in quantum mechanical four-fermi models which act as a prototype of models for chiral symmetry breaking in Quantum Electrodynamics. It has been shown that AFM, defined by an insertion of Gaussian identity to path integral formulas and by the loop expansion, becomes more accurate when t

R. D&#39;Auria, S. Ferrara, M. Trigiante

We report on some recent investigations of the structure of the four dimensional gauged supergravity Lagrangian which emerges from flux and Scherk-Schwarz compactifications in higher dimensions. Special attention is given to the gauge structure of M-theory compactified on a seven torus with 4-form and geometrical (spin connection) fluxes turned on. A class o

Hiroshi Nunokawa, Stephen Parke, Renata Zukanovich Funchal

We calculate the fraction of B^8 solar neutrinos that arrive at the Earth as a nu_2 mass eigenstate as a function of the neutrino energy. Weighting this fraction with the B^8 neutrino energy spectrum and the energy dependence of the cross section for the charged current interaction on deuteron with a threshold on the kinetic energy of the recoil electrons of

Johan Bijnens, Elvira Gamiz, Joaquim Prades

We introduce four-point functions in the hadronic ladder resummation approach to large $N_c$ QCD Green functions. We determine the relevant one to calculate the $B_K$ kaon parameter in the chiral limit. This four-point function contains both the large momenta QCD OPE and the small momenta ChPT at NLO limits, analytically. We get $\hat B_K^χ= 0.38 \pm 0.15$.

Michael D. Scadron, Frieder Kleefeld, George Rupp

Chiral symmetry breaking (ChSB) is reviewed to some extent within the quark-level-linear-sigma-model (QLL$σ$M) theory and standard chiral perturbation theory (ChPT). It is shown, on the basis of several examples related to the pion, as a well-known Goldstone boson of chiral symmetry breaking, that even the non-unitarized QLL$σ$M approach accounts, to a good

R. F. Avila, M. J. Menon

It is shown that, for a wide class of functions with physical interest as forward scattering amplitudes, integral dispersion relations can be replaced by derivative forms without any high-energy approximation. The applicability of these extended derivative relations, in the investigation of forward proton-proton and antiproton-proton elastic scattering, is e

Artan Borici, Alban Allkoci

In this work we compare the convergence of the shifted unitary orthogonal method (SUOM) and different Krylov subspace solvers for propagator computations with overlap fermions. We show that the SUOM algorithm performs similarly to the shifted unitary minimal residual method (SUMR) with the latter converging slightly faster. When the geometric optimality is a

Alban Allkoci, Artan Borici

The beta-shift induced from dynamical domain wall quarks leads to increased roughness of the gauge field, thus reversing the effect of smoothing from the gauge action improvement. By exploiting the relation of overlap and domain wall fermions in greater detail,we propose an algorithm which reduces the beta-shift to the level of dynamical overlap fermions.

The DELPHI Collaboration, J. Abdallah

The production of single charged and neutral intermediate vector bosons in e+e- collisions has been studied in the data collected by the DELPHI experiment at LEP at centre-of-mass energies between 183 and 209 GeV, corresponding to an integrated luminosity of about 640 pb^{-1}. The measured cross-sections for the reactions, determined in limited kinematic reg

H C Eggers, B Buschbeck, F J October

Correlations of like-sign pion pairs emerging from proton-antiproton collisions are analysed in the two-dimensional (q_L,q_T) decomposition of the three-momentum difference q. While the data cannot be adequately represented by gaussian, exponential, power-law or Edgeworth parametrisations, more elaborate ones such as Levy and an exponential with a cross term

Theodora Ioannidou, Burkhard Kleihaus, Jutta Kunz

We construct globally regular gravitating Skyrmions, which possess only discrete symmetries. In particular, we present tetrahedral and cubic Skyrmions. The SU(2) Skyrme field is parametrized by an improved harmonic map ansatz. Consistency then requires also a restricted ansatz for the metric. The numerical solutions obtained within this approximation are com

Valentino Lacquaniti, Giovanni Montani

Our purpose is to recast KK model in terms of ADM variables. We examine and solve the problem of the consistency of this approach, with particular care about the role of the cylindricity hypothesis. We show in details how the KK reduction commutes with the ADM slicing procedure and how this leads to a well defined and unique ADM reformulation. This allows us

Iver Brevik

We consider a modified form of gravity in which the action contains a power alpha of the scalar curvature. It is shown how the presence of a bulk viscosity in a spatially flat universe may drive the cosmic fluid into the phantom region (w<-1) and thus into a Big Rip singularity, even if it lies in the quintessence region (w>-1) in the non-viscous case. The c

Matthew Anderson, Jung-Han Kimn

We study a space-time finite element approach for the nonhomogeneous wave equation using a continuous time Galerkin method. We present fully implicit examples in 1+1, 2+1, and 3+1 dimensions using linear quadrilateral, hexahedral, and tesseractic elements. Krylov solvers with additive Schwarz preconditioning are used for solving the linear system. We introdu

Martin Bojowald

Degenerate geometrical configurations in quantum gravity are important to understand if the fate of classical singularities is to be revealed. However, not all degenerate configurations arise on an equal footing, and one must take into account dynamical aspects when interpreting results: While there are many degenerate spatial metrics, not all of them are ap

Vassilios S. Vassiliadis

This short article presents an alternative view of high resolution imaging from various sources with the aim of the discovery of potential sites of archaeological importance, or sites that exhibit `anomalies&#39; such that they may merit closer inspection and analysis. It is conjectured, and to a certain extent demonstrated here, that it is possible for adva

Philipp Mayr, Fabio Tosques

This paper introduces Google Web APIs (Google APIs) as an instrument and playground for webometric studies. Several examples of Google APIs implementations are given. Our examples show that this Google Web Service can be used successfully for informetric Internet based studies albeit with some restrictions.

Robert S. Caprari

This article examines the design of Quadratic Fisher Discriminants (QFDs) that operate directly on image pixels, when image ensembles are taken to comprise all rotated and reflected versions of distinct sample images. A procedure based on group theory is devised to identify and discard QFD coefficients made redundant by symmetry, for arbitrary sampling latti

B. S. Shajeemohan, Dr. V. K. Govindan

Compression algorithms reduce the redundancy in data representation to decrease the storage required for that data. Data compression offers an attractive approach to reducing communication costs by using available bandwidth effectively. Over the last decade there has been an unprecedented explosion in the amount of digital data transmitted via the Internet,

Vladimir Vovk

We consider the problem of on-line prediction of real-valued labels, assumed bounded in absolute value by a known constant, of new objects from known labeled objects. The prediction algorithm&#39;s performance is measured by the squared deviation of the predictions from the actual labels. No stochastic assumptions are made about the way the labels and object

Zhenyu Yan, Sergey V. Buldyrev, Nicolas Giovambattista, H. Eugene Stanley

We perform molecular dynamics simulations to investigate the relationship between structural order and water-like dynamic and thermodynamic anomalies in spherically-symmetric potentials having either one or two characteristic length scales. %The first potential has only one length scale which is the diameter of the ramp %without the hard core, and the second

I. Martin, Y. M. Galperin

Low-temperature dynamics of insulating glasses is dominated by a macroscopic concentration of tunneling two-level systems (TTLS). The distribution of the switching/relaxation rates of TTLS is exponentially broad, which results in non-equilibrium state of the glass at arbitrarily long time-scales. Due to the electric dipolar nature, the switching TTLS generat

B. S. Alexandrov, L. T. Wille, K. O. Rasmussen, A. R. Bishop

The dynamical properties of double-stranded DNA are studied in the framework of the Peyrard-Bishop-Dauxois model using Langevin dynamics. Our simulations are analyzed in terms of two probability functions describing coherently localized separations (&#34;bubbles&#34;) of the double strand. We find that the resulting bubble distributions are more sharply peak

Zhenyu Yan, Sergey V. Buldyrev, Nicolas Giovambattista, Pablo G. Debenedetti

We investigate the equation of state, diffusion coefficient, and structural order of a family of spherically-symmetric potentials consisting of a hard core and a linear repulsive ramp. This generic potential has two characteristic length scales: the hard and soft core diameters. The family of potentials is generated by varying their ratio, $λ$. We find negat

Wei Zhang, C. A. R. Sa de Melo

We discuss the possibility of coexistence of spin density wave (antiferromagnetism) and triplet superconductivity as a particular example of a broad class of systems where the interplay of magnetism and superconductivity is important. We focus on the case of quasi-one-dimensional metals, where it is kown that antiferromagnetism is in close proximity to tripl

N. Regnault, Th. Jolicoeur

We investigate possible parafermionic states in rapidly rotating ultracold bosonic atomic gases at lowest Landau level filling factor nu=k/2. We study how the system size and interactions act upon the overlap between the true ground state and a candidate Read-Rezayi state. We also consider the quasihole states which are expected to display non-Abelian statis

H. Choi, J. P. Davis, J. Pollanen, W. P. Halperin

High resolution measurements of the specific heat of liquid $^{3}$He in the presence of a silver surface have been performed at temperatures near the superfluid transition in the pressure range of 1 to 29 bar. The surface contribution to the heat capacity is identified with Andreev bound states of $^{3}$He quasiparticles that have a range of half a coherence

F. Brosens, S. N. Klimin, J. T. Devreese

A translation invariant N-polaron system is investigated at arbitrary electron-phonon coupling strength, using a variational principle for path integrals for identical particles. An upper bound for the ground state energy is found as a function of the number of spin up and spin down polarons, taking the electron-electron interaction and the Fermi statistics

Xavier Moya, Lluís Mañosa, Antoni Planes, Thorsten Krenke

Inelastic and elastic neutron scattering have been used to study a single crystal of the Ni$_{54}$Mn$_{23}$Al$_{23}$ Heusler alloy over a broad temperature range. The paper reports the first experimental determination of the low-lying phonon dispersion curves for this alloy system. We find that the frequencies of the TA$_2$ modes are relatively low. This bra

F. Pérez-Willard, D. Wolde-Giorgis, T. Al-Kassab, G. A. López

Needle-shaped atom probe specimens containing a single grain boundary were produced using the focused ion beam (FIB) of a dual-beam FIB/SEM (scanning electron microscope) system. The presented specimen preparation approach allows the unprecedented study of a grain boundary which is well characterised in its crystallographic orientation by means of the field

H. Kusumaatmaja, J. Leopoldes, A. Dupuis, J. M. Yeomans

We compare numerical and experimental results exploring the behaviour of liquid drops moving across a surface patterned with hydrophobic and hydrophilic stripes. A lattice Boltzmann algorithm is used to solve the hydrodynamic equations of motion of the drops allowing us to investigate their behaviour as the stripe widths and the wettability contrast are alte

Miriam del Valle, Carlos Tejedor, Gianaurelio Cuniberti

A new form of gold nanobridges has been recently observed in ultrahigh-vacuum experiments, where the gold atoms rearrange to build helical nanotubes, akin in some respects to carbon nanotubes. The good reproducibility of these wires and their unexpected stability will allow for conductance measurements and make them promising candidates for future applicatio

W. V. Pogosov, R. Kawate, T. Mizushima, K. Machida

Extended Gross-Pitaevskii equations for the rotating F=2 condensate in a harmonic trap are solved both numerically and variationally using trial functions for each component of the wave function. Axially-symmetric vortex solutions are analyzed and energies of polar and cyclic states are calculated. The equilibrium transitions between different phases with ch

H. Watanabe, Y. Mori, M. Yokoi, T. Moyoshi

Co-oxides beta-Na0.5CoO2 and gamma-K0.5CoO2 have been prepared by the Na de-intercalation from alpha-NaCoO2 and by the floating-zone method, respectively. It has been found that successive phase transitions take place at temperatures Tc1 and Tc2 in both systems. The appearance of the internal magnetic field at Tc1 with decreasing temperature T indicates that

J. Mur-Petit, A. Sarsa, J. Navarro, A. Polls

Binding energies and density profiles of two-dimensional systems of liquid He-4 with different geometries are studied by means of a zero-range density functional adjusted to reproduce the line tension obtained in a previous diffusion Monte Carlo calculation (lambda_{DMC}=0.121 K/A). It is shown that this density functional provides accurate results for the b

Gyong Luck Khym, Youngnae Lee, Kicheon Kang

We study charge detection and controlled dephasing of a mesoscopic system via a quantum dot detector (QDD), where the mesoscopic system and the QDD are capacitively coupled. The QDD is considered to have coherent resonant tunnelling via a single level. It is found that the dephasing rate is proportional to the square of the conductance of the QDD for the Bre

S. L. Narasimhan

We present a Monte Carlo study of the Backgammon model, at zero temperature, in which a departure box is chosen at random with a probability proportional to $(2ω- 1)k + (1 - ω)N$, where $k$ is the number of particles in the departure box and $N$ is the total number of particles (equivalently, boxes) in the system. The parameter $ω\in [0,1]$ tunes the dynamic

J. Kwiatkowska, B. Barbiellini, S. Kaprzyk, A. Bansil

We report high resolution Compton scattering measurements on an Al$_{97}$Li$_3$ disordered alloy single crystal for momentum transfer along the [100], [110] and [111] symmetry directions. The results are interpreted via corresponding KKR-CPA (Korringa-Kohn-Rostoker coherent potential approximation) first principles computations. By comparing spectra for Al$_

T. Torsti, T. Eirola, J. Enkovaara, T. Hakala

A characteristic feature of the state-of-the-art of real-space methods in electronic structure calculations is the diversity of the techniques used in the discretization of the relevant partial differential equations. In this context, the main approaches include finite-difference methods, various types of finite-elements and wavelets. This paper reports on t

Alex Khaneles

Integer lattice gas automata can be utilized as building blocks in statistical mechanics. The presented deterministic and reversible automaton generates semiclassical statistical distributions. A possible approach to Bose-Einstein statistics from cellular automata position is discussed.

Tai Kai Ng

We show that the rather unexpected pressure dependence of superfluid density observed near the superfluid-supersolid transition by Kim {\em et.al.}[M.H.W. Chan, {\em private communication}], can be understood if the transition from superfluid to supersolid state is a second order or weakly first order transition from the superfluid state to a super-CDW state

Thilo Stöferle, Henning Moritz, Kenneth Günter, Michael Köhl

We create molecules from fermionic atoms in a three-dimensional optical lattice using a Feshbach resonance. In the limit of low tunnelling, the individual wells can be regarded as independent three-dimensional harmonic oscillators. The measured binding energies for varying scattering length agree excellently with the theoretical prediction for two interactin

Rafael A. Molina, Dietmar Weinmann, Jean-Louis Pichard

In order to extend the Landauer formulation of quantum transport to correlated fermions, we consider a spinless system in which charge carriers interact, connected to two reservoirs by non-interacting one-dimensional leads. We show that the mapping of the embedded many-body scatterer onto an effective one-body scatterer with interaction-dependent parameters

Fabio D. Barazza, Shardha Jogee, Hans-Walter Rix, Marco Barden

We present a study of the colors, structural properties, and star formation histories for a sample of ~1600 dwarfs over look-back times of ~3 Gyr (z=0.002-0.25). The sample consists of 401 distant dwarfs drawn from the Galaxy Evolution from Morphologies and SEDs (GEMS) survey, which provides high resolution Hubble Space Telescope (HST) Advanced Camera for Su

Vincent L. Fish, Mark J. Reid

We analyze full-polarization VLBA data of ground-state, main-line OH masers in 18 massive star-forming regions previously presented in a companion paper. The OH masers often arise in the shocked neutral gas surrounding ultracompact Hii regions. Magnetic fields as deduced from OH maser Zeeman splitting are highly ordered, both on the scale of a source as well

Scott Burles, Saul Rappaport

The motion of the solar system barycenter with respect to the cosmic microwave background (CMB) induces a very large apparent dipole component into the CMB brightness map at the 3 mK level. In this Letter we discuss another kinematic effect of our motion through the CMB: the small shift in apparent angular positions due to the aberration of light. The aberra

Maxim Lyutikov

The Swift X-Ray Telescope often observes a rapidly decaying X-ray emission stretching to as long as $ t \sim 10^3$ seconds after a conventional prompt phase. This component is most likely due to a prompt emission viewed at large observer angles $θ> 1/Γ$, where $θ\sim 0.1$ is a typical viewing angle of the jet and$Γ\geq 100$ is the Lorentz factor of the flow

Maria Rodriguez Martinez, Tsvi Piran, Yonatan Oren

Various approaches to quantum gravity suggest the possibility of violation of Lorentz symmetry at very high energies. In these cases we expect a modification at low energies of the dispersion relation of photons that contains extra powers of the momentum suppressed by a high energy scale. These terms break boost invariance and can be tested even at relativel

Fabrizio Brighenti, William G. Mathews

We describe 2D gasdynamical models of jets that carry mass as well as energy to the hot gas in galaxy clusters. These flows have many attractive attributes for solving the galaxy cluster cooling flow problem: Why the hot gas temperature and density profiles resemble cooling flows but show no spectral evidence of cooling to low temperatures. Using an approxim

H. M. Cuppen, O. Morata, Eric Herbst

Continuous-time, random-walk Monte Carlo simulations of H2 formation on grains have been performed for surfaces that are stochastically heated by photons. We have assumed diffuse cloud conditions and used a variety of grains of varying roughness and size based on olivine. The simulations were performed at different optical depths. We confirmed that small gra

E. Aprile, C. E. Dahl, L. DeViveiros, R. Gaitskell

We report the first measurements of the absolute ionization yield of nuclear recoils in liquid xenon, as a function of energy and electric-field. Independent experiments were carried out with two dual-phase time projection chamber prototypes, developed for the XENON Dark Matter project. We find that the charge yield increases with decreasing recoil energy, a

Brian E. Wood, Jeffrey L. Linsky

We have used Chandra to resolve the nearby 70 Oph (K0 V+K5 V) and 36 Oph (K1 V+K1 V) binary systems for the first time in X-rays. The LETG/HRC-S spectra of all four of these stars are presented and compared with an archival LETG spectrum of another moderately active K dwarf, Epsilon Eri. Coronal densities are estimated from O VII line ratios and emission mea

S. L. Skinner, A. E. Simmons, S. A. Zhekov, M. Teodoro

Recent optical and IR studies have revealed that the heavily-reddened starburst cluster Westerlund 1 (Wd 1) contains at least 22 Wolf-Rayet (WR) stars, comprising the richest WR population of any galactic cluster. We present results of a senstive Chandra X-ray observation of Wd 1 which detected 12 of the 22 known WR stars and the mysterious emission line sta

W. F. Wall

The reliability of modeling the far-IR continuum to 13CO J=1-0 spectral line ratios applied to the Orion clouds (Wall 2006) is tested by applying the models to simulated data. The two-component models are found to give the dust-gas temperature difference, $\DT$, to within 1 or 2$ $K. However, other parameters like the column density per velocity interval and

S. Piatek, C. Pryor, P. Bristow, E. W. Olszewski

This article presents a measurement of the proper motion of the Sculptor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope using the Space Telescope Imaging Spectrograph in the imaging mode.

K. Werner, T. Nagel, T. Rauch, N. J. Hammer

We present new medium-resolution high-S/N optical spectra of the ultracompact low-mass X-ray binaries 4U0614+091 and 4U1626-67, taken with the ESO Very Large Telescope. They are pure emission line spectra and the lines are identified as due to C II-IV and O II-III Line identification is corroborated by first results from modeling the disk spectra with detail

Aharonian et al.

The high-frequency peaked BL Lac PG 1553+113 was observed in 2005 with the H.E.S.S. stereoscopic array of imaging atmospheric-Cherenkov telescopes in Namibia. Using the H.E.S.S. standard analysis, an excess was measured at the 4.0 sigma level in these observations (7.6 hours live time). Three alternative, lower-threshold analyses yield >5 sigma excesses. The

Steven L. Finkelstein, Jon A. Morse, James C. Green, Jeffrey L. Linsky

We present new optical emission-line images of the young SNR 1E 0102-7219 (E0102) in the SMC obtained with the HST Advanced Camera for Surveys (ACS). E0102 is a member of the oxygen-rich class of SNRs showing strong oxygen, neon , and other metal-line emissions in its optical and X-ray spectra, and an absence of H and He. The progenitor of E0102 may have bee

A. E. Shabad, V. V. Usov

A hypercritical value for the magnetic field is determined, which provides the full compensation of the positronium rest mass by the binding energy in the maximum symmetry state and disappearance of the energy gap separating the electron-positron system from the vacuum. The compensation becomes possible owing to the falling to the center phenomenon. The stru

D. Batcheldor, A. Robinson, D. Axon, D. C. Hines

The value of accurately knowing the absolute calibration of the polarizing elements in the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) becomes especially important when conducting studies which require measuring degrees of polarization of close to 1% in the near infrared. We present a comprehensive study of all previously observed polarimetri

Magaretha L. Pretorius, Brian Warner, Patrick A. Woudt

We present observations of dwarf nova oscillations (DNOs), longer period dwarf nova oscillations (lpDNOs), and quasi-periodic oscillations (QPOs) in 13 cataclysmic variable stars (CVs). In the six systems WW Cet, BP CrA, BR Lup, HP Nor, AG Hya, and V1193 Ori, rapid, quasi-coherent oscillations are detected for the first time. For the remainder of the systems

Will J. Percival

In this manuscript I review the mathematics and physics that underpins recent work using the clustering of galaxies to derive cosmological model constraints. I start by describing the basic concepts, and gradually move on to some of the complexities involved in analysing galaxy redshift surveys, focusing on the 2dF Galaxy Redshift Survey (2dFGRS) and the Slo

P. Brun, S. Rosier-Lees

Test beam data collected in October 2004 at CERN PS to validate the AMS02 Ecal Intermediate Board (EIB) are analyzed. After describing the experimental setup and the event samples, results concerning noise measurement, trigger efficiency and threshold accuracy are presented. They demonstrate that the EIB fulfils the physics requirements. Therefore the analog

Nalin de Silva

A model for the universe with both acceleration and deceleration is given. The model incorporates an initial acceleration, then a deceleration as has been observed by Schaefer in respect of gamma ray bursts, a second phase of acceleration that would explain the observations by Perlmutter et.al. on supernovae, and a second phase of deceleration in the future.

A. Tej, D. K. Ojha, S. K. Ghosh, V. K. Kulkarni

We present a multiwavelength study of the massive star forming region associated with IRAS 06055+2039 which reveals an interesting scenario of this complex where regions are at different stages of evolution of star formation. Narrow band near-infrared (NIR) observations were carried out with UKIRT-UFTI in molecular hydrogen and Br$γ$ lines to trace the shock