June 2007 arXiv papers — page 34

Silvio M. Duarte Queiros

In this manuscript we analyse the leading statistical properties of fluctuations of (log) 3-month US Treasury bill quotation in the secondary market, namely: probability density function, autocorrelation, absolute values autocorrelation, and absolute values persistency. We verify that this financial instrument, in spite of its high liquidity, shows very pecu

Philip F. Hopkins, Thomas J. Cox, Dusan Keres, Lars Hernquist

(Abridged) We develop and test a model for the cosmological role of mergers in the formation and quenching of red, early-type galaxies. Making the ansatz that star formation is quenched after a gas-rich, spheroid-forming major merger, we demonstrate that this naturally predicts the turnover in the efficiency of star formation at ~L_star, as well as the obser

Philip F. Hopkins, Lars Hernquist, Thomas J. Cox, Dusan Keres

(Abridged) We develop a model for the cosmological role of mergers in the evolution of starbursts, quasars, and spheroidal galaxies. Combining halo mass functions (MFs) with empirical halo occupation models, we calculate where major galaxy-galaxy mergers occur and what kinds of galaxies merge, at all redshifts. We compare with observed merger MFs, clustering

B. Uchoa, C. -Y. Lin, A. H. Castro Neto

We study the effects of metallic doping on the electronic properties of graphene using density functional theory in the local density approximation in the presence of a local charging energy (LDA+U). The electronic properties are sensitive to whether graphene is doped with alkali or transition metals. We estimate the the charge transfer from a single layer o

Michael Creutz

Using effective Lagrangian arguments, I explore the qualitative behavior expected at finite temperature for two flavor lattice QCD formulated with Wilson fermions and a twisted mass term. A rather rich phase structure is predicted, exhibiting Aoki's parity violating phase along with a deconfinement region forming a conical structure in the space of coupl

Stefano Ansoldi, Eduardo I. Guendelman

Baby universes (inflationary or non--inflationary) are regions of spacetime that disconnect from the original ambient spacetime, which we take to be asymptotically flat spacetime. A particular kind of baby universe solution, involving string--like matter, is studied to show that it can be formed by ``investing'' an arbitrarily small amount of energy,

Jarah Evslin, Chethan Krishnan

We use the inverse scattering method (ISM) to derive concentric non-supersymmetric black rings. The approach used here is fully five-dimensional, and has the modest advantage that it generalizes readily to the construction of more general axi-symmetric solutions.

V. Barger, D. Marfatia, K. Whisnant

We show that the combined data from solar, long-baseline and reactor neutrino experiments can exclude the generalized bicycle model of Lorentz noninvariant direction-dependent and/or direction-independent oscillations of massless neutrinos. This model has five parameters, which is more than is needed in standard oscillation phenomenology with neutrino masses

A. M. Ghezelbash

We construct generalized 11D supergravity solutions of fully localized intersecting D2/D4 brane systems. These solutions are obtained by embedding six-dimensional resolved Eguchi-Hanson conifolds lifted to M-theory. We reduce these solutions to ten dimensions, obtaining new D-brane systems in type IIA supergravity. We discuss the limits in which the dynamics

Francisco Correa, Mikhail S. Plyushchay

A hidden nonlinear bosonized supersymmetry was revealed recently in Poschl-Teller and finite-gap Lame systems. In spite of the intimate relationship between the two quantum models, the hidden supersymmetry in them displays essential differences. In particular, the kernel of the supercharges of the Poschl-Teller system, unlike the case of Lame equation, inclu

Jose C. C. de Souza, Valerio Faraoni

We study the geometry of the phase space of spatially flat Friedmann-Lemaitre-Robertson-Walker models in f(R) gravity, for a general form of the function f(R). The equilibrium points (de Sitter spaces) and their stability are discussed, and a comparison is made with the phase space of the equivalent scalar-tensor theory. New effective Lagrangians and Hamilto

M. Sun, M. Donahue, G. M. Voit

We present the discovery of a 40 kpc H-alpha tail and at least 29 emission-line objects downstream of a star-forming galaxy ESO 137-001 in the rich, nearby cluster A3627. The galaxy is known to possess a dramatic 70 kpc X-ray tail. The detected H-alpha tail coincides positionally with the X-ray tail. The H-alpha emission in the galaxy is sharply truncated on

Thomas Decker, Jan Draisma, Pawel Wocjan

We consider a natural generalization of an abelian Hidden Subgroup Problem where the subgroups and their cosets correspond to graphs of linear functions over a finite field F with d elements. The hidden functions of the generalized problem are not restricted to be linear but can also be m-variate polynomial functions of total degree n>=2. The problem of iden

S. Brendle

Let (M,g_0) be a compact Riemannian manifold of dimension n \geq 4. We show that the normalized Ricci flow deforms g_0 to a constant curvature metric provided that (M,g_0) x R has positive isotropic curvature. This condition is stronger than 2-positive flag curvature but weaker than 2-positive curvature operator.

Evgeny Akhmedov

The question of whether charged leptons oscillate is discussed in detail, with a special emphasis on the coherence properties of the charged lepton states created via weak interactions. This analysis allows one to clarify also an important issue of the theory of neutrino oscillations.

Piera L. Ghia

The building block of the surface detector of the Pierre Auger Observatory is a water Cherenkov tank. The response to shower particles is simulated using a dedicated program based on GEANT4. To check the simulation chain, we compare the simulated signals produced by cosmic muons at various zenith angles with experimental data from a special Cherenkov detecto

Dimitar G. Stoyanov

The elementary processes taking place in the formation of charged particles and their flow in the ionization chamber are considered. On the basic of particles and charges balance a differential equation describing the distribution of current densities in the ionization chamber volume is obtained. As a result of the differential equation solution an analytica

Paul H. Frampton, Thomas W. Kephart

Present data on neutrino masses and mixing favor the highly symmetric tribimaximal neutrino mixing matrix which suggests an underlying flavor symmetry. A systematic study of non-abelian finite groups of order $g \leq 31$ reveals that tribimaximal mixing can be derived not only from the well known tetrahedral flavor symmetry $T \equiv A_4$, but also by using

S. Friot, G. Grunberg

We verify to order alpha_s^4 two previously conjectured relations, valid in four dimensions, between constant terms in threshold resummation (for Deep Inelastic Scattering and the Drell-Yan process) and the second logarithmic derivative of the massless quark form factor. The same relations are checked to all orders in the large beta_0 limit; as a byproduct a

Tanmay Vachaspati

Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed "black stars". Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star g

Todd M. Tripp, Kenneth R. Sembach, David V. Bowen, Blair D. Savage

Using high-resolution UV spectra of 16 low-z QSOs, we study the physical conditions and statistics of O VI absorption in the IGM at z < 0.5. We identify 51 intervening (z_{abs} << z_{QSO}) O VI systems comprised of 77 individual components, and we find 14 &#34;proximate&#34; systems (z_{abs} ~ z_{QSO}) containing 34 components. For intervening systems [compo

Svjetlana Fajfer, Nejc Kosnik, Sasa Prelovsek

Motivated by recent experimental results on charm physics we investigate implications of the updated constraints of new physics in rare charm meson decays. We first reconsider effects of the MSSM in $c\to u γ$ constrained by the recent experimental evidence on $Δm_D$ and find, that due to the dominance of long distance physics, $D \to V γ$ decay rates cannot

Daniela Alic, Carles Bona, Carles Bona-Casas, Joan Massó

Centered finite volume methods are considered in the context of Numerical Relativity. A specific formulation is presented, in which third-order space accuracy is reached by using a piecewise-linear reconstruction. This formulation can be interpreted as an &#39;adaptive viscosity&#39; modification of centered finite difference algorithms. These points are ful

P. A. Curran, A. J. van der Horst, R. A. M. J. Wijers, R. L. C. Starling

Gamma-ray burst afterglow observations in the Swift era have a perceived lack of achromatic jet breaks compared to the BeppoSAX era. We present our multi-wavelength analysis of GRB 060206 as an illustrative example of how inferences of jet breaks from optical and X-ray data might differ. The results of temporal and spectral analyses are compared, and attempt

A. V. Gorbach, D. V. Skryabin

The use of photonic crystal fibers pumped by femtosecond pulses has enabled the generation of broad optical supercontinua with nano-joule input energies. This striking discovery has applications ranging from spectroscopy and metrology to telecommunication and medicine. Amongst the physical principles underlying supercontinuum generation are soliton fission,

Jingfei Zhang, Xin Zhang, Hongya Liu

We propose in this Letter a holographic model of tachyon dark energy. A connection between the tachyon scalar-field and the holographic dark energy is established, and accordingly, the potential of the holographic tachyon field is constructed. We show that the holographic evolution of the universe with $c\geqslant 1$ can be described completely by the result

F. Intravaia, C. Henkel, A. Lambrecht

In this paper we study the role of surface plasmon modes in the Casimir effect. The Casimir energy can be written as a sum over the modes of a real cavity and one may identify two sorts of modes, two evanescent surface plasmon modes and propagative modes. As one of the surface plasmon modes becomes propagative for some choice of parameters we adopt an adiaba

Dominic Schuhmacher

Based on Stein&#39;s method, we derive upper bounds for Poisson process approximation in the $L_1$-Wasserstein metric $d_2^{(p)}$, which is based on a slightly adapted $L_p$-Wasserstein metric between point measures. For the case $p=1$, this construction yields the metric $d_2$ introduced in [Barbour and Brown Stochastic Process. Appl. 43 (1992) 9--31], for

Giorgio Parisi, Tommaso Rizzo

We compute analytically the probability distribution of large deviations in the spin-glass free energy for the Sherrington-Kirkpatrick mean field model, i.e. we compute the exponentially small probability of finding a system with intensive free energy smaller than the most likely one. This result is obtained by computing the average value of the partition fu

Hiroaki Kohyama

We construct the phase diagrams of the quark-antiquark and diquark condensates at finite temperature and density in the 3D (dimensional) 2-flavor Gross Neveu model. We found that, in contrast to the case of the 4D Nambu Jona-Lasinio model, there is no region where the quark-antiquark and diquark condensates coexist. The phase diagrams obtained for some param

Yvan Martel, Frank Merle

We consider the generalized Korteweg-de Vries equation $$ \partial_t u + \partial_x (\partial_x^2 u + f(u))=0, \quad (t,x)\in [0,T)\times \mathbb{R}$$ with general $C^2$ nonlinearity $f$. Under an explicit condition on $f$ and $c>0$, there exists a solution in the energy space $H^1$ of the type $u(t,x)=Q_c(x-x_0-ct)$, called soliton. Stability theory for $Q_

Tomasz Grzywny, Michał Ryznar

The purpose of this paper is to find optimal estimates for the Green function of a half-space of {\it the relativistic $α$-stable process} with parameter $m$ on $\Rd$ space. This process has an infinitesimal generator of the form $mI-(m^{2/α}I-Δ)^{α/2},$ where $0<α<2$, $m>0$, and reduces to the isotropic $α$-stable process for $m=0$. Its potential theory for

Yvan Martel, Frank Merle

We consider the generalized Korteweg-de Vries equation \partial_t u + \partial_x (\partial_x^2 u + f(u))=0, \quad (t,x)\in [0,T)\times \mathbb{R}, (1) with general $C^3$ nonlinearity $f$. Under an explicit condition on $f$ and $c>0$, there exists a solution in the energy space $H^1$ of (1) of the type $u(t,x)=Q_c(x-x_0-ct)$, called soliton. In this paper, un

R. Gerritsma, S. Whitlock, T. Fernholz, H. Schlatter

We have realized a two dimensional permanent magnetic lattice of Ioffe-Pritchard microtraps for ultracold atoms. The lattice is formed by a single 300 nm magnetized layer of FePt, patterned using optical lithography. Our magnetic lattice consists of more than 15000 tightly confining microtraps with a density of 1250 traps/mm$^2$. Simple analytical approximat

Maro Cvitan, Predrag Dominis Prester, Silvio Pallua, Ivica Smolić

We analyse near-horizon solutions and compare the results for the black hole entropy of five-dimensional spherically symmetric extremal black holes when the N=2 SUGRA actions are supplied with two different types of higher-order corrections: (1) supersymmetric completion of gravitational Chern-Simons term, and (2) Gauss-Bonnet term. We show that for large BP

Hikaru Kawai, Takao Suyama

We study an anisotropic scale transformation in the worldsheet description of D3-branes in Type IIB theory, and show that the transformation is really a symmetry in a region near D3-branes. AdS/CFT correspondence follows from this symmetry. We will explicitly show that Wilson loops in N=4 supersymmetric Yang-Mills theory and minimal surfaces in AdS_5 are rel

Bjorn Andreas, Gottfried Curio

We modify a recently proposed heterotic model hep-th/0703210, giving three net-generations of standard model fermions, to get rid of an additional U(1) factor in the gauge group. The method employs a stable SU(5) bundle on a Calabi-Yau threefold admitting a free involution. The bundle has to be built as a deformation of the direct sum of a stable SU(4) bundl

A. V. Minkevich, A. S. Garkun, V. I. Kudin

Homogeneous isotropic cosmological models with two torsion functions filled with scalar fields and usual gravitating matter are built and investigated in the framework of the Poincaré gauge theory of gravity. It is shown that by certain restrictions on indefinite parameters of gravitational Lagrangian the cosmological equations at asymptotics contain an effe

Salvatore Capozziello, Mauro Francaviglia

We review Extended Theories of Gravity in metric and Palatini formalism pointing out their cosmological and astrophysical application. The aim is to propose an alternative approach to solve the puzzles connected to dark components.

Susumu Oda

We have studied a faded problem, the Jacobian Conjecture ~: \noindent {\sf The Jacobian Conjecture $(JC_n)$}~: If $f_1, \cdots, f_n$ are elements in a polynomial ring $k[X_1, \cdots, X_n]$ over a field $k$ of characteristic $0$ such that the Jacobian $\det(\partial f_i/ \partial X_j) $ is a nonzero constant, then $k[f_1, \cdots, f_n] = k[X_1, \cdots, X_n]$.

Gunnar Pruessner

The universal behaviour of the directed percolation universality class is well understood, both the critical scaling as well as finite size scaling. This article focuses on the block (finite size) scaling of the order parameter and its fluctuations, considering (sub-)blocks of linear size l in systems of linear size L. The scaling depends on the choice of th

Saikat Chatterjee, Amitabha Lahiri, Ambar N. Sengupta

We present an account of negative differential forms within a natural algebraic framework of differential graded algebras, and explain their relationship with forms on path spaces.

Sayan Kar, Rajesh R. Parwani

We point out that bound states, degenerate in energy but differing in parity, may form in one dimensional quantum systems even if the potential is non-singular in any finite domain. Such potentials are necessarily unbounded from below at infinity and occur in several different contexts, such as in the study of localised states in brane-world scenarios. We de

F. Farchioni, I. Montvay, G. Münster, E. E. Scholz

One-flavour QCD - a gauge theory with SU(3) colour gauge group and a fermion in the fundamental representation - is studied by Monte Carlo simulations. The mass spectrum of hadronic bound states is investigated in a volume with extensions of L ~ 4.4r_0 (~2.2fm) at two different lattice spacings: a ~ 0.37r_0 (~0.19fm) and a ~ 0.27r_0 (~0.13fm). The lattice ac

Tomoyuki Maruyama, George F. Bertsch

We study the dipole collective oscillations in the bose-fermi mixture using a dynamical time-dependent approach, which are formulated with the time-dependent Gross-Pitaevskii equation and the Vlasov equation. We find big difference in behaviors of fermion oscillation between the time-dependent approach and usual approaches such as the random-phase approximat

Mircea Mustata, Ken-ichi Yoshida

The generalized test ideals introduced in [HY] are related to multiplier ideals via reduction to characteristic p. In addition, they satisfy many of the subtle properties of the multiplier ideals, which in characteristic zero follow via vanishing theorems. In this note we give several examples to emphasize the different behavior of test ideals and multiplier

Peter Haïssinsky, Kevin M. Pilgrim

Let $f: S^2 \to S^2$ be an expanding branched covering map of the sphere to itself with finite postcritical set $P_f$. Associated to $f$ is a canonical quasisymmetry class $\GGG(f)$ of Ahlfors regular metrics on the sphere in which the dynamics is (non-classically) conformal. We show \[ \inf_{X \in \GGG(f)} \hdim(X) \geq Q(f)=\inf_Γ\{Q \geq 2: λ(f_{Γ,Q}) \ge

Guofang Wei, Will Wylie

For Riemannian manifolds with a measure $(M,g, e^{-f} dvol_g)$ we prove mean curvature and volume comparison results when the $\infty$-Bakry-Emery Ricci tensor is bounded from below and $f$ is bounded or $\partial_r f$ is bounded from below, generalizing the classical ones (i.e. when $f$ is constant). This leads to extensions of many theorems for Ricci curva

Stefan Z. Stefanov

The paper makes a thermal predictive analysis of the electric power system security for a day ahead. This predictive analysis is set as a thermal computation of the expected security. This computation is obtained by cointegrating the daily electric power systen load and the weather, by finding the daily electric power system thermodynamics and by introducing

Kazuhito Mizuyama, Masayuki Matsuo, Yasuyoshi Serizawa

We develop a new formulation of the continuum quasiparticle random phase approximation (QRPA) in which the residual interaction is derived directly from the Skyrme energy functional, keeping all the velocity dependent terms of the Skyrme effective interaction. Numerical analysis using the SkM$^*$ parameter set is performed for the isovector dipole and the is

Shao-Long Chen, Xiao-Gang He, A. Hovhannisyan, Ho-Chin Tsai

We study R-parity violating contributions to the mixing parameter $y$ for $D^0 -\bar D^0$ and $B^0_{d,s} - \bar B^0_{d,s}$ systems. We first obtain general expressions for new physics contributions to $y$ from effective four fermion operators. We then use them to study R-parity contributions. We find that R-parity violating contributions to $D^0 - \bar D^0$

Roy P. Kerr

An historical account of the reasoning that led to the discovery of the Kerr and Kerr-Schild metrics in 1963-1964, and their physical interpretation as rotating black holes, is presented.

Lam Hui, Enrique Gaztanaga, Marilena LoVerde

It is well known gravitational lensing, mainly via magnification bias, modifies the observed galaxy/quasar clustering. Such discussions have largely focused on the 2D angular correlation. Here and in a companion paper (Paper II) we explore how magnification bias distorts the 3D correlation function and power spectrum, as first considered by Matsubara. The in

Robert H. Brandenberger, Andrew R. Frey, Sugumi Kanno

It has recently been speculated that the end state of a collapsing universe is a tachyonic big crunch. The time reversal of this process would be the emergence of an expanding universe from a tachyonic big bang. In this framework, we study the emergence of cosmological fluctuations. In particular, we compare the amplitude of the perturbations at tne end of t

Christian Remling

I explore some consequences of a groundbreaking result of Breimesser and Pearson on the absolutely continuous spectrum of one-dimensional Schr&#34;odinger operators. These include an Oracle Theorem that predicts the potential and rather general results on the approach to certain limit potentials. In particular, we prove a Denisov-Rakhmanov type theorem for t

Daniel J. Rogers, Joshua C. Bienfang, Anastase Nakassis, Hai Xu

Recent advances in quantum key distribution (QKD) have given rise to systems that operate at transmission periods significantly shorter than the dead times of their component single-photon detectors. As systems continue to increase in transmission rate, security concerns associated with detector dead times can limit the production rate of sifted bits. We pre

Hirotaka Tamanoi

Chas and Sullivan proved the existence of a Batalin-Vilkovisky algebra structure in the homology of free loop spaces on closed finite dimensional smooth manifolds using chains and chain homotopies. This algebraic structure involves an associative product called the loop product, a Lie bracket called the loop bracket, and a square 0 operator called the BV ope

Katherine A. Kretke, D. N. C. Lin

The first challenge in the formation of both terrestrial planets and the cores of gas giants is the retention of grains in protoplanetary disks. In most regions of these disks, gas attains sub-Keplerian speeds as a consequence of a negative pressure gradient. Hydrodynamic drag leads to orbital decay and depletion of the solid material in the disk, with chara

Katrin Heitmann, Zarija Lukic, Patricia Fasel, Salman Habib

Current and upcoming cosmological observations allow us to probe structures on smaller and smaller scales, entering highly nonlinear regimes. In order to obtain theoretical predictions in these regimes, large cosmological simulations have to be carried out. The promised high accuracy from observations make the simulation task very demanding: the simulations

E. Dudas, J. Mourad, F. Nitti

We analyze vacuum decay in brane world setups, where a free scalar field in five dimensions has a localized potential admitting metastable vacua. We study in particular the bounce solution and its properties in flat and warped spaces. In the latter case, placing into a deeply warped region the term in the potential that lifts the vacuum degeneracy, can incre

J. Soubusta, L. Bartuskova, A. Cernoch, J. Fiurasek

We compare several optical implementations of phase-covariant cloning machines. The experiments are based on copying of the polarization state of a single photon in bulk optics by special unbalanced beam splitter or by balanced beam splitter accompanied by a state filtering. Also the all-fiber based setup is discussed, where the information is encoded into s

Keh-Fei Liu

Combining the recent lattice calculation of $a_0(1450)$ and $σ(600)$ mesons with the overlap fermion in the chiral regime with the pion mass less than $300 {\rm MeV}$, the quenched lattice calculation of the scalar glueball, and the phenomenological study of the mixing of isoscalar scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$ through their decays, a s

Stefan Tsonchev, Rob D. Coalson, Anthony Duncan

A lattice field theory approach to the statistical mechanics of charged polymers in electrolyte solutions [S. Tsonchev, R. D. Coalson, and A. Duncan, Phys. Rev. E 60, 4257, (1999)] is applied to the study of a polymer chain contained in a spherical cavity but able to diffuse into a surrounding gel. The distribution of the polymer chain between the cavity and

Frank Reifler, Randall Morris

Defining a spin connection is necessary for formulating Dirac&#39;s bispinor equation in a curved space-time. Hestenes has shown that a bispinor field is equivalent to an orthonormal tetrad of vector fields together with a complex scalar field. In this paper, we show that using Hestenes&#39; tetrad for the spin connection in a Riemannian space-time leads to

X. Bertou

The Pierre Auger Observatory, with an array of currently more than 1200 Cherenkov detectors filled with 12 m$^3$ of water, can detect the putative high energy emission of a GRB (photons down to a few hundreds of MeV) by the so-called ``single particle technique&#39;&#39;, through a coherent increase in the average background particle rates over the whole arr

Cynthia Aku-Leh, Florent Perez, Bernard Jusserand, David Richards

We compare resonant electronic Raman scattering and photoluminescence measurements for the characterization of a spin-polarized two-dimensional electron gas embedded in $\text{Cd}_{1-x}\text{Mn}_x\text{Te}$ single quantum wells. From Raman scattering by single-particle excitations in a zero magnetic field, we measure the Fermi velocity and then obtain the Fe

A. Zoia, A. Rosso, M. Kardar

The fractional Laplacian operator, $-(-\triangle)^{\fracα{2}}$, appears in a wide class of physical systems, including Lévy flights and stochastic interfaces. In this paper, we provide a discretized version of this operator which is well suited to deal with boundary conditions on a finite interval. The implementation of boundary conditions is justified by ap

P. Sokolsky, G. B. Thomson

The status of the field of ultrahigh energy cosmic rays is summarized, from the point of view of the latest results of the High Resolution Fly&#39;s Eye (HiRes) Experiment. HiRes results are presented, and compared with those of the Akeno Giant Air Shower Array (AGASA), plus the Telescope Array and Pierre Auger experiments. The HiRes measurements of the cosm

N. T. Huy, D. E. de Nijs, A. Gasparini, J. C. P. Klaasse

We have investigated the evolution of ferromagnetic order in the correlated metal series URh_{1-x}Ru_{x}Ge. Magnetization, transport and specific heat measurements provide convincing evidence for a ferromagnetic quantum critical point at the critical concentration x_{c} = 0.38. Here we report ac-susceptibility and magnetization measurements on selected sampl

J. A. Eisner

Planetary systems, ours included, are formed in disks of dust and gas around young stars. Disks are an integral part of the star and planet formation process, and knowledge of the distribution and temperature of inner disk material is crucial for understanding terrestrial planet formation, giant planet migration, and accretion onto the central star. While th

B. I. Cohen, E. A. Williams, H. X. Vu

An investigation of the possible inflation of stimulated Brillouin backscattering (SBS) due to ion kinetic effects is presented using electromagnetic particle simulations and integrations of three-wave coupled-mode equations with linear and nonlinear models of the nonlinear ion physics. Electrostatic simulations of linear ion Landau damping in an ion acousti

Edward W. Thommes, Geoffrey Bryden, Yanqin Wu, Frederic A. Rasio

We show that interaction with a gas disk may produce young planetary systems with closely-spaced orbits, stabilized by mean-motion resonances between neighbors. On longer timescales, after the gas is gone, interaction with a remnant planetesimal disk tends to pull these configurations apart, eventually inducing dynamical instability. We show that this can le

Jorge Antezana, Enrique Pujals, Demetrio Stojanoff

Let $λ\in (0,1)$ and let $T$ be a $r\times r$ complex matrix with polar decomposition $T=U|T|$. Then, the $\la$- Aluthge transform is defined by $$ Δ_λ(T )= |T|^λ U |T |^{1-λ}. $$ Let $Δ_λ^{n}(T)$ denote the n-times iterated Aluthge transform of $T$, $n\in\mathbb{N}$. We prove that the sequence $\{Δ_λ^{n}(T)\}_{n\in\mathbb{N}}$ converges for every $r\times r

Yakir Aharonov, Jeff Tollaksen

A review of new aspects concerning time-symmetry in Quantum Mechanics.

A. R. P. Rau

Efimov&#39;s prediction more than three decades ago that three-body bound states can exist when the pairwise attractions do not bind or only support weakly bound states of a pair, has remained unconfirmed till just the past year. This lecture provides the pedagogical background for recent work on Efimov states in neutron-rich nuclei done with I. Mazumdar (TI

A. D. Dolgov

Two scenarios of low temperature baryogenesis in theories with TeV scale gravity are discussed. It is argued that strong gravity at TeV energies is very favorable for baryogenesis. In both scenarios the proton decay is either absent or suppressed far below existing bounds. On the other hand, neutron-antineutron oscillations are at the verge of discovery. Som

Wellington Alves de Brito, Rubens Viana Ramos

The interferometry of single-photon pulses has been used to implement quantum technology systems, like quantum key distribution, interaction-free measurement and some other quantum communication protocols. In most of these implementations, Mach-Zehnder, Michelson and Fabry-Perot interferometers are the most used. In this work we present optical setups for in

C. A. de S. Pires

In this work we consider the standard model extended with singlet sterile neutrinos with mass in the eV range and mixed with the active neutrinos. The active-sterile neutrino mixing renders new contributions to the invisible Z decay width which, in the case of light sterile neutrinos, depends on the active-sterile mixing matrix elements only. We then use the

Young-Heon Kim, Robert J. McCann

We are interested in the cost-convex potentials in optimal mass transport theory, and we show by direct and geometric arguments the equivalence between cost-subdifferentials and ordinary subdifferentials of cost-convex functions, under the assumptions A0, A1, A2, and A3W on cost functions introduced by Ma, Trudinger, and Wang. The connectivity of contact set

Grazyna Stasinska, Guillermo Tenorio-Tagle, Monica Rodriguez, William J. Henney

We critically examine a scenario for the enrichment of the interstellar medium (ISM) in which supernova ejecta follow a long (10^8 yr) journey before falling back onto the galactic disk in the form of metal-rich ``droplets&#39;&#39;, These droplets do not become fully mixed with the interstellar medium until they become photoionized in HII regions. We invest

V. Rivasseau

We extend the technique of constructive expansions to compute the connected functions of matrix models in a uniform way as the size of the matrix increases. This provides the main missing ingredient for a non-perturbative construction of the $ϕ^{\star 4}_4$ field theory on the Moyal four dimensional space.

A. García-Camacho, G. Blanchon, A. Bonaccorso, D. M. Brink

We present a semiclassical method to treat the proton breakup from a weakly bound state in an exotic nucleus. The Coulomb interactions between the proton, core and target are treated to all orders and including the full multipole expansion of the Coulomb potential. The nuclear proton-target interaction is also treated to all orders. The core-target interacti

T. S. Boyajian, D. R. Gies, E. K. Baines, P. Barai

We present new results from a radial velocity study of six bright OB stars with little or no prior measurements. One of these, HD 45314, may be a long-period binary, but the velocity variations of this Be star may be related to changes in its circumstellar disk. Significant velocity variations were also found for HD 60848 (possibly related to nonradial pulsa

Chao Tian, Vinay A. Vaishampayan, N. J. A. Sloane

We present a novel technique for encoding and decoding constant weight binary codes that uses a geometric interpretation of the codebook. Our technique is based on embedding the codebook in a Euclidean space of dimension equal to the weight of the code. The encoder and decoder mappings are then interpreted as a bijection between a certain hyper-rectangle and

Lars Kadison

We introduce a notion of depth three tower of three rings C < B < A as a useful generalization of depth two ring extension. If A = End B_C and B | C is a Frobenius extension, this also captures the notion of depth three for a Frobenius extension in math.RA/0107064 and math.RA/0108067 such that if B | C is depth three, then A | C is depth two (cf. math.QA/000

H. L. Worters, S. P. S Eyres, G. E. Bromage, J. P. Osborne

The latest outburst of the recurrent nova RS Oph occurred in 2006 February. Photometric data presented here show evidence of the resumption of optical flickering, indicating re-establishment of accretion by day 241 of the outburst. Magnitude variations of up to 0.32 mag in V-band and 0.14 mag in B on timescales of 600-7000 s are detected. Over the two week o

Ryan Stearrett, L. Q. English

Experimental evidence for the generation of intrinsic localized modes (ILMs) in a nonlinear electrical transmission line is presented both via modulational instability (MI) of the uniform mode and via driving the lattice locally. The spatial profiles of these modes localized on the order of the lattice spacing can be directly measured in this macroscopic lat

Carlos R. Pontes, A. P. Baêta Scarpelli, Marcos Sampaio, J. L. Acebal

Constrained Differential Renormalization (CDR) and the constrained version of Implicit Regularization (IR) are two regularization independent techniques that do not rely on dimensional continuation of the space-time. These two methods which have rather distinct basis have been successfully applied to several calculations which show that they can be trusted a

Volker Schomerus

During the last ten years, intriguing dualities between gauge and string theory have been found and explored. They provide a novel window on strongly coupled gauge physics, including QCD-like models. Based on a short historical review of modern string theory, we shall explain how so-called AdS/CFT dualities emerged at the end of the 1990s. Some of their conc

F. Eurich, A. Karatchentsev, J. Baschnagel, W. Dieterich

A soft particle model for diblock (AB) copolymer melts is proposed. Each molecule is mapped onto two soft spheres built by Gaussian A- and B-monomer distributions. An approximate analytical expression for the joint distribution function for the distance between both spheres and their radii of gyration is derived, which determines the entropic contribution to

Francesco Fumarola, Erich J. Mueller

We use a T-matrix approximation to calculate the single particle spectrum of the normal state of a gas of Fermionic atoms at low temperature. In the strongly interacting regime of the polarized gas, we find that the spectrum is separated in two branches, leading to a double-peaked radiofrequency spectral feature.

M. Gieles, H. J. G. L. M. Lamers, S. F. Portegies Zwart

We re-analyze the age distribution (dN/dt) of star clusters in the Small Magellanic Cloud (SMC) using age determinations based on the Magellanic Cloud Photometric Survey. For ages younger than 3x10^9 yr the dN/dt distribution can be approximated by a power-law distribution, dN/dt propto t^-beta, with -beta=-0.70+/-0.05 or -beta=-0.84+/-0.04, depending on the

Jose Eduardo M. Lobo, Jorge Luis Risco Becerra, Matthias R. Brust, Steffen Rothkugel

With larger memory capacities and the ability to link into wireless networks, more and more students uses palmtop and handheld computers for learning activities. However, existing software for Web-based learning is not well-suited for such mobile devices, both due to constrained user interfaces as well as communication effort required. A new generation of ap

Tooru Taniguchi, E. G. D. Cohen

Inertial effects in fluctuations of the work to sustain a system in a nonequilibrium steady state are discussed for a dragged massive Brownian particle model using a path integral approach. We calculate the work distribution function in the laboratory and comoving frames and prove the asymptotic fluctuation theorem for these works for any initial condition.

Anirban Banerjee, Jürgen Jost

It is basic question in biology and other fields to identify the char- acteristic properties that on one hand are shared by structures from a particular realm, like gene regulation, protein-protein interaction or neu- ral networks or foodwebs, and that on the other hand distinguish them from other structures. We introduce and apply a general method, based on

Antonio De Felice, Pia Mukherjee, Yun Wang

Modified gravity provides a possible explanation for the currently observed cosmic accelaration. In this paper, we study general classes of modified gravity models. The Einstein-Hilbert action is modified by using general functions of the Ricci and the Gauss-Bonnet scalars, both in the metric and in the Palatini formalisms. We do not use an explicit form for

Jian-Wei Qiu, Werner Vogelsang, Feng Yuan

We study the single transverse-spin asymmetry for dijet production in hadronic collisions in both the collinear QCD factorization approach and the Brodsky-Hwang-Schmidt model. We show that a nonvanishing asymmetry is generated by both initial-state and final-state interactions, and that the final-state interactions dominate. We find that in the leading kinem

N. C. Bishop, M. Padmanabhan, K. Vakili, Y. P. Shkolnikov

We report magnetotransport measurements of fractional quantum Hall states in an AlAs quantum well around Landau level filling factor nu = 3/2, demonstrating that the quasiparticles are composite Fermions (CFs) with a valley degree of freedom. By monitoring the valley level crossings for these states as a function of applied symmetry-breaking strain, we deter

Alain Albouy, Yanning Fu, Shanzhong Sun

We study the relationship between the masses and the geometric properties of central configurations. We prove that in the planar four-body problem, a convex central configuration is symmetric with respect to one diagonal if and only if the masses of the two particles on the other diagonal are equal. If these two masses are unequal, then the less massive one

S. Meissner, A. Metz, K. Goeke

The present knowledge on non-trivial relations between generalized parton distributions on the one hand and transverse momentum dependent distributions on the other is reviewed. While various relations can be found in the framework of spectator models, so far no model-independent non-trivial relations have been established.