January 2006 arXiv papers — page 33

L. Alvarez-Ruso, T. Leitner, U. Mosel

We investigate neutrino-nucleus collisions at intermediate energies incorporating quasielastic scattering and Delta(1232) excitation as elementary processes, together with Fermi motion, Pauli blocking and mean-field potentials in the nuclear medium. A full coupled-channel treatment of final state interactions is achieved with a semiclassical BUU transport mo

David d'Enterria

High energy ultra-peripheral collisions (UPC) of heavy-ions generate strong electromagnetic fields which open the possibility to study gamma-gamma and gamma-nucleus processes in a kinematic regime so far unexplored. We report on preliminary PHENIX results of J/Psi and high-mass e+e- photoproduction at mid-rapidity in coherent electromagnetic Au+Au interactio

Alexis Pokrovski

Consider quantum harmonic oscillator, perturbed by an even almost-periodic complex-valued potential with bounded derivative and primitive. Suppose that we know the first correction to the spectral asymptotics $\{Δμ_n\}_{n=0}^\infty$ ($Δμ_n=μ_n-μ_n^0+o(n^{-1/4})$, where $μ_n^0$ and $μ_n$ is the spectrum of the unperturbed and the perturbed operators, respecti

Michael Hardy

The natural forms of the Leibniz rule for the $k$th derivative of a product and of Faà di Bruno's formula for the $k$th derivative of a composition involve the differential operator $\partial^k/\partial x_1 ... \partial x_k$ rather than $d^k/dx^k$, with no assumptions about whether the variables $x_1,...,x_k$ are all distinct, or all identical, or partit

Mouna Kraiem

Let $Ω$ be a smooth bounded domain in $\R^N, N>1$ and let $n\in \N^*$. We are concerned here with the existence of nonnegative solutions $u\_n$ in $BV(Ω)$, to the problem $$(P\_n) \begin{cases} -{\rm div} σ+2n (\int\_ Ωu -1) {\rm sign}^+ (u)=0 \quad \text{in} Ω, σ\cdot \nabla u= |\nabla u| \quad \text{in} Ω, u \text{\rm is not identically zero}, -σ\cdot \ove

Antoine Deza, Sui Huang, Tamon Stephen, Tamás Terlaky

Inspired by Barany's colourful Caratheodory theorem, we introduce a colourful generalization of Liu's simplicial depth. We prove a parity property and conjecture that the minimum colourful simplicial depth of any core point in any d-dimensional configuration is d^2+1 and that the maximum is d^(d+1)+1. We exhibit configurations attaining each of these

Jim Colliander, Mark Keel, Gigliola Staffilani, Hideo Takaoka

We obtain global well-posedness, scattering, and global $L^{10}_{t,x}$ spacetime bounds for energy-class solutions to the quintic defocusing Schrödinger equation in $\R^{1+3}$, which is energy-critical. In particular, this establishes global existence of classical solutions. Our work extends the results of Bourgain and Grillakis, which handled the radial cas

M. Chaisi, S. D. Maharaj

We establish a new algorithm that generates a new solution to the Einstein field equations, with an anisotropic matter distribution, from a seed isotropic solution. The new solution is expressed in terms of integrals of an isotropic gravitational potential; and the integration can be completed exactly for particular isotropic seed metrics. A good feature of

Yapeng Hu, Jingyi Zhang, Zheng Zhao

In Parikh and Wilczek's original works, the laws of black hole thermodynamics are not referred and it seems that there is no relation between Hawking radiation via tunnelling and the laws of black hole thermodynamics in their works. However, taking examples for the R-N black hole and the Kerr black hole, we find that they are correlated and even consiste

Fabrice Gerbier, Artur Widera, Simon Foelling, Olaf Mandel

We study experimentally interaction-driven spin oscillations in optical lattices in the presence of an off-resonant microwave field. We show that the energy shift induced by this microwave field can be used to control the spin oscillations by tuning the system either into resonance to achieve near-unity contrast or far away from resonance to suppress the osc

F. Y. Wu

We obtain the critical threshold for a host of Potts and percolation models on lattices having a structure which permits a duality consideration. The consideration generalizes the recently obtained thresholds of Scullard and Ziff for bond and site percolation on the martini and related lattices to the Potts model and to other lattices.

Baleegh Abdo, Eran Segev, Oleg Shtempluck, Eyal Buks

In this work we report on unusual nonlinear dynamics measured in the resonance response of NbN superconducting microwave resonators. The nonlinear dynamics, occurring at relatively low input powers (2-4 orders of magnitude lower than Nb), and which include among others, jumps in the resonance lineshape, hysteresis loops changing direction and resonance frequ

Eli Barkai

We investigate statistics of occupation times for an over-damped Brownian particle in an external force field. A backward Fokker-Planck equation introduced by Majumdar and Comtet describing the distribution of occupation times is solved. The solution gives a general relation between occupation time statistics and probability currents which are found from sol

T. I. Baturina, Yu. A. Tsaplin, A. E. Plotnikov, M. R. Baklanov

We have investigated low-temperature transport properties of two-dimensional arrays of superconductor--normal-metal--superconductor (SNS) junctions. It has been found that in two-dimensional arrays of SNS junctions (i) a change in the energy spectrum within an interval of the order of the Thouless energy is observed even when the thermal broadening far excee

D. J. Whalen, S. A. Laurent-Muehleisen, E. C. Moran, R. H. Becker

We present results from the analysis of the optical spectra of 47 radio-selected narrow-line Seyfert 1 galaxies (NLS1s). These objects are a subset of the First Bright Quasar Survey (FBQS) and were initially detected at 20 cm (flux density limit ~1 mJy) in the VLA FIRST Survey. We run Spearman rank correlation tests on several sets of parameters and conclude

Kanak Saha, Chanda J. Jog

We study the self-consistent, linear response of a galactic disc to vertical perturbations as induced say by a tidal interaction. We calculate the self-gravitational potential corresponding to a non-axisymmetric, self-consistent density response of the disc using the Green's function method. The response potential is shown to oppose the perturbation pote

Franco Ferrari, Ewa Szuszkiewicz

Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. After almost a century since their discovery, a huge amount of scientific literature has been written on this topic and it is not always easy to extract from it the necessary information for somebody who approaches the subject for the first time. This has been

Wen-xin Chen, Andrei M. Beloborodov

We calculate the structure of accretion disk around a spinning black hole for accretion rates 0.01 - 10 M_sun/s. The model is fully relativistic and treats accurately the disk microphysics including neutrino emissivity, opacity, electron degeneracy, and nuclear composition. We find that the accretion flow always regulates itself to a mildly degenerate state

Éanna É. Flanagan, Étienne Racine

In coalescing neutron star binaries, r-modes in one of the stars can be resonantly excited by the gravitomagnetic tidal field of its companion. This post-Newtonian gravitomagnetic driving of these modes dominates over the Newtonian tidal driving previously computed by Ho and Lai. To leading order in the tidal expansion parameter R/r (where R is the radius of

Luz Maria Diaz-Rivera, Lado Samushia, Bharat Ratra

We find exact exponentially expanding and contracting de Sitter solutions of the spatially homogeneous TeVeS cosmological equations of motion in the vacuum TeVeS model and a power law accelerated expanding solution in thepresence of an additional ideal fluid with equation of state parameter $-5/3 < ω< -1$. A preliminary stability analysis shows that the expa

Bjorn Poonen

Let k be an algebraically closed field of characteristic p. Let X(p^e;N) be the curve parameterizing elliptic curves with full level N structure (where p does not divide N) and full level p^e Igusa structure. By modular curve, we mean a quotient of any X(p^e;N) by any subgroup of ((Z/p^e Z)^* x \SL_2(Z/NZ))/{+-1}. We prove that in any sequence of distinct mo

M. J. Way, A. N. Srivastava

We calculate photometric redshifts from the Sloan Digital Sky Survey Main Galaxy Sample, The Galaxy Evolution Explorer All Sky Survey, and The Two Micron All Sky Survey using two new training-set methods. We utilize the broad-band photometry from the three surveys alongside Sloan Digital Sky Survey measures of photometric quality and galaxy morphology. Our f

Paulina Marian, Tudor A. Marian, Horia Scutaru

We propose a reliable entanglement measure for a two-mode squeezed thermal state of the quantum electromagnetic field in terms of its Bures distance to the set of all separable states of the same kind. The requisite Uhlmann fidelity of a pair of two-mode squeezed thermal states is evaluated as the maximal transition probability between two four-mode purifica

Denis Traeger, Robert Fischer, Dragomir N. Neshev, Andrey A. Sukhorukov

We generate experimentally different types of two-dimensional Bloch waves of a square photonic lattice by employing the phase imprinting technique. We probe the local dispersion of the Bloch modes in the photonic lattice by analyzing the linear diffraction of beams associated with the high-symmetry points of the Brillouin zone, and also distinguish the regim

M. S. Bhagwat, P. C. Tandy

Recent lattice-QCD results for the dressed-gluon propagator are used within the quark Dyson-Schwinger equation to determine the gluon-quark vertex dressing necessary to reproduce the lattice-QCD results for the dressed-quark propagator. Both quenched and full QCD lattice simulations, for a range of low quark current masses, are analyzed. The chiral extrapola

Kazuyuki Oshima

We disclose the Lie algebraic structure of two extended Sutherland models. Their Hamiltonians are BC_N, and A_N Sutherland Hamiltonians with some additional terms. We show that both Hamiltonians can be written in the quadratic forms of generators of the Lie algebra gl(N+1).

Marco Merkli

Level shift operators describe the second order displacement of eigenvalues under perturbation. They play a central role in resonance theory and ergodic theory of open quantum systems at positive temperatures. We exhibit intrinsic properties of level shift operators, properties which stem from the structure of open quantum systems at positive temperatures an

Roland K. W. Roeder

Given a combinatorial description $C$ of a polyhedron having $E$ edges, the space of dihedral angles of all compact hyperbolic polyhedra that realize $C$ is generally not a convex subset of $\mathbb{R}^E$ \cite{DIAZ}. If $C$ has five or more faces, Andreev&#39;s Theorem states that the corresponding space of dihedral angles $A_C$ obtained by restricting to {

Matthias Baaz, Norbert Preining, Richard Zach

First-order Goedel logics are a family of infinite-valued logics where the sets of truth values V are closed subsets of [0, 1] containing both 0 and 1. Different such sets V in general determine different Goedel logics G_V (sets of those formulas which evaluate to 1 in every interpretation into V). It is shown that G_V is axiomatizable iff V is finite, V is

Ko Honda

The goal of this article is to survey recent developments in the theory of contact structures in dimension three.

David W. Farmer, Sarah Zubairy

It is believed that Dirichlet series with a functional equation and Euler product of a particular form are associated to holomorphic newforms on a Hecke congruence group. We perform computer algebra experiments which find that in certain cases one can associate a kind of ``higher order modular form&#39;&#39; to such Dirichlet series. This suggests a possible

Nikos Frantzikinakis

In 1993, E. Lesigne proved a polynomial extension of the Wiener-Wintner ergodic theorem and asked two questions: does this result have a uniform counterpart and can an assumption of total ergodicity be replaced by ergodicity? The purpose of this article is to answer these questions, the first one positively and the second one negatively.

Stefano Beltraminelli, Danilo Merlini

The original criteria of Riesz and of Hardy-Littlewood concerning the truth of the Riemann Hypothesis (RH) are revisited and further investigated in light of the recent formulations and results of Maslanka and of Baez-Duarte concerning a representation of the Riemann Zeta function. Then we introduce a general set of similar functions with the emergence of Po

Michal Stukow

Let t_a be the Dehn twist about a circle a on an orientable surface. It is well known that for each circle b and an integer n, I(t_a^n(b),b)=|n|I(a,b)^2, where I(,) is the geometric intersection number. We prove a similar formula for circles on nonorientable surfaces. As a corollary we prove some algebraic properties of twists on nonorientable surfaces. We a

Lev Sakhnovich

We investigate the asymptotic behavior of sample functions of stable processes when $t{\to}\infty$. We compare our results with the iterated logarithm law, results for the first hitting time and most visited sites problems.

Mitya Boyarchenko

If A is a finite dimensional nilpotent associative algebra over a finite field k, the set G=1+A of all formal expressions of the form 1+a, where a is an element of A, has a natural group structure, given by (1+a)(1+b)=1+(a+b+ab). A finite group arising in this way is called an algebra group. One can also consider G as a unipotent algebraic group over k. We s

Jamel Ghanouchi

It is an original method based on systems of prameters represented by reals which obey to an infinite descent (convergent sequences). We define calculus of quotients and they conduct quickly to a consequent result. Our own scepticism made us doubt and we did errors, but the proof is correct !

Alex E. Bernardini

In the framework of intermediate wave-packets for treating flavor oscillations, we quantify the modifications which appear when we assume a strictly peaked momentum distribution and consider the second-order corrections in a power series expansion of the energy. By following a sequence of analytic approximations, we point out that an extra time-dependent pha

G. Barnich, G. Bonelli, M. Grigoriev

In this short note we show, at the level of action principles, how the light-cone action of higher spin gauge fields can easily be obtained from the BRST formulation through the elimination of quartets. We analyze how the algebra of cohomology classes is affected by such a reduction. By applying the reduction to the Poincare generators, we give an alternativ

Fernando Cornet

In the last year four new parametrizations of the Hadronic Photon Structure Function at Next to Leading Order have appeared. In this talk, I briefly review the main features of three of them: the FFNS_CJK, CJK and AFG.

H. Abuki, T. Kunihiro

We discuss the phase structure of homogeneous quark matter under the charge neutrality constraints, and present a unified picture of the thermal unpairing phase transitions for a wide range of the quark density. We supplement our discussions by developing the Ginzburg-Landau analysis.

A. N

The authors are not satisfied about the analysis.

C. B. Lang, Pushan Majumdar, Wolfgang Ortner

We discuss some properties of zero and near-zero modes of the Dirac operator, as observed in a recent simulation of 2-flavor QCD. The quarks have been implemented with the so-called Chirally Improved Dirac operator, which obeys the Ginsparg-Wilson relation to a good approximation. We present geometrical and statistical properties of these eigenmodes and eige

Earnest Harrison

Certain semi-Riemannian metrics may be decomposed into a Riemannian part and an isochronal part. We use this idea and an idea of Kasner to construct a manifold in 6+1 Minkowski space with a well known metric. The full embedding we display is isochronal which simplifies visualizing the properties of the manifold.

Alexander Haubold

We introduce a novel approach to control physical lighting parameters by means of a pressure-sensitive touchpad. The two-dimensional area of the touchpad is subdivided into 5 virtual sliders, each controlling the intensity of a color (red, green, blue, yellow, and white). The physical interaction methodology is modeled directly after ubiquitous mechanical sl

David Mann, Eric Pop, Jien Cao, Qian Wang

The high-bias electrical transport properties of suspended metallic single-walled carbon nanotubes (SWNTs) are investigated at various temperatures in vacuum, in various gases and when coated with molecular solids. It is revealed that non-equilibrium optical phonon effects in suspended nanotubes decrease as the ambient temperature increases. Gas molecules su

V. V. Bilykh

We theoretically calculate the polariton linewidth associated with the polariton-electron scattering in a microcavity in presence of a magnetic field perpendicular to the microcavity plane. It is shown that the polariton linewidth oscillates as a function of the magnetic field magnitude and the polariton-electron scattering rate can be not only decreased but

Masahiko Higuchi, Katsuhiko Higuchi

The density functional scheme for calculating the pair density is presented by means of the constrained-search technique. The resultant single-particle equation takes the form of the modified Hartree-Fock equation which contains the kinetic contribution of the exchange-correlation energy functional as the correlation potential. The practical form of the kine

D. J. Reilly, Y. Zhang, L. DiCarlo

We describe a phenomenological model for the conductance feature near $0.7 \times 2e^2/h$ that occurs in quantum point contacts. We focus on the transconductance at finite source-drain bias and contrast our model with the results expected from a single-particle picture. Good agreement is seen in comparing the model with experimental data, taken on ultra-low-

M. B. Stone, M. D. Lumsden, R. Jin, B. C. Sales

The Ruthenium based perovskites exhibit a wide variety of interesting collective phenomena related to magnetism originating from the Ru 4d electrons. Much remains unknown concerning the nature of magnetic fluctuations and excitations in these systems. We present results of detailed inelastic neutron scattering measurements of Sr3Ru2O7 as a function of temper

K. Sugawara, T. Sato, S. Souma, T. Takahashi

High-resolution angle-resolved photoemission spectroscopy has been performed on Sb(111) to elucidate the origin of anomalous electronic properties in group-V semimetal surfaces. The surface was found to be metallic despite the semimetallic character of bulk. We clearly observed two surface-derived Fermi surfaces which are likely spin split, demonstrating tha

T. Yamashita, S. Takahashi, S. Maekawa

We propose a novel Josephson device in which 0 and $π$ states are controlled by an electrical current. In this system, the $π$ state appears in a superconductor/normal metal/superconductor junction due to the non-local spin accumulation in the normal metal which is induced by spin injection from a ferromagnetic electrode. Our proposal offers not only new pos

A. J. Williams, J. P. Attfield, M. L. Foo, R. J. Cava

The structure of Na0.5CoO2, the low temperature insulator that separates the magnetic and superconducting regions in the NaxCoO2.yH2O phase diagram, is studied by high resolution powder neutron diffraction at temperatures between 10 and 300 K. Profile analysis confirms that it has an orthorhombic symmetry structure, space group Pnmm, consisting of layers of

Frederic Zagury, Mitsugu Fujii

We analyze and fit visible spectra of a red horizon at sunrise. The shape of the spectra consist of a blue continuum followed by a red bump. The reddest spectra are well fitted by the product of a spectrum of extinguished sunlight (Rayleigh extinction + ozone absorption) and 1/lambda^4. The former is essentially the radiation field in the outer atmosphere, a

Frederic Zagury, Florence Goutail

SAOZ (Systeme d&#39;Analyse par Observation Zenitale) is a balloon born experiment which determines the column density of several molecular species from the visible spectrum of sunlight. We will use sequence of spectra collected during a sunset to discuss atmospheric extinction, and the nature of the radiation field in the atmosphere. The radiation field in

Alexandre Pélangeon, Jean-Luc Atteia, Don Q. Lamb, George R. Ricker

We propose an improved version of the redshift indicator developed by Atteia (2003), which gets rid of the dependence on the burst duration and provides better estimates for high-redshift GRBs. We present the derivation and the definition of this redshift indicator, then its calibration with 17 GRBs with known redshifts detected by HETE-2 and 2 more detected

Yozo Kawano, Masamune Oguri

We investigate the dependence of the time delays for the large-separation gravitationally lensed quasar SDSS J1004+4112 on the inner mass profile of the lensing cluster. Adopting the mass model whose innermost density profile is parameterized as ρ\propto r^{-α}, we derive a series of mass models which can fit observational data and then compute the probabili

I. Kravchenko

We present new limits on ultra-high energy neutrino fluxes above 100 PeV based on data collected by the Radio Ice Cherenkov Experiment (RICE) at the South Pole from 1999-2005. We discuss estimation of backgrounds, calibration and data analysis algorithms (both on-line and off-line), procedures used for the dedicated neutrino search, and refinements in our Mo

Alice C. Quillen, Joss Bland-Hawthorn, Mairi H. Brookes, Michael W. Werner

Spitzer Space Telescope mid-infrared images of the radio galaxy Centaurus A reveal a shell-like, bipolar, structure 500 pc to the north and south of the nucleus. This shell is seen in 5.8, 8.0 and 24 micron broad-band images. Such a remarkable shell has not been previously detected in a radio galaxy and is the first extragalactic nuclear shell detected at mi

Daniel Kocevski, Edison Liang

We estimate the luminosity evolution and formation rate for over 900 GRBs by using redshift and luminosity data calculated by Band, Norris, $&$ Bonnell (2004) via the lag-luminosity correlation. By applying maximum likelihood techniques, we are able to infer the true distribution of the parent GRB population&#39;s luminosity function and density distribution

Jun Fukue

Radiatively-driven transfer flow perpendicular to a luminous disk is examined in the subrelativistic regime of $(v/c)^1$, taking into account the gravity of the central object. The flow is assumed to be vertical, and the gas pressure is ignored, while internal heating is assumed to be proportional to the gas density. The basic equations were numerically solv

Jun Fukue

Radiatively-driven flow in a luminous disk is examined in the subrelativistic regime of $(v/c)^1$, taking account of radiation transfer. The flow is assumed to be vertical, and the gravity and gas pressure are ignored. When internal heating is dropped, for a given optical depth and radiation pressure at the flow base (disk ``inside&#39;&#39;), where the flow

Rui Neves, Cenalo Vaz

In the Randall-Sundrum scenario, we analyse the dynamics of an AdS5 braneworld when conformal matter fields propagate in five dimensions. We show that conformal fields of weight -4 are associated with stable geometries which describe the dynamics of inhomogeneous dust, generalized dark radiation and homogeneous polytropic dark energy on a spherically symmetr

Charles D. Dermer, Armen Atoyan

The accretion of ~ 0.1 -- 1 M_o of material by a neutron star through Roche lobe overflow of its companion or through white-dwarf/neutron-star coalescence in a low mass binary system could be enough to exceed the critical mass of a neutron star and trigger its collapse to a black hole, leading to the production of a short gamma-ray burst (SGRB). In this mode

Sean Lawton

Denote the free group on two letters by F2 and the SL(3,C)-representation variety of F2 by R = Hom(F2, SL(3,C)). There is a SL(3,C)-action on the coordinate ring of R, and the geometric points of the subring of invariants is an affine variety X. We determine explicit minimal generators and defining relations for the subring of invariants and show X is a degr

Stephen M. Barr, Siew-Phang Ng, Robert J. Scherrer

We revisit a scenario in which the cosmological constant is cancelled by the potential energy of a slowly evolving scalar field, or &#34;cosmon&#34;. The cosmon&#39;s evolution is tied to the cosmological constant by a feedback mechanism. This feedback is achieved by an unconventional coupling of the cosmon field to the Ricci curvature scalar. The solutions

Freddy Cachazo, Marcus Spradlin, Anastasia Volovich

Planar L-loop maximally helicity violating amplitudes in N = 4 supersymmetric Yang-Mills theory are believed to possess the remarkable property of satisfying iteration relations in L. We propose a simple new method for studying the iteration relations for four-particle amplitudes which involves the use of certain linear differential operators and eliminates

Simon Turbide, Charles Gale, Dinesh K. Srivastava, Rainer J. Fries

We discuss the emission of high momentum lepton pairs in central Au+Au collisions at RHIC ($\sqrt{s_{NN}}=$200 GeV) and Pb+Pb collisions at the LHC ($\sqrt{s_{NN}}=$5500 GeV). Yields of dileptons produced through interactions of jets with thermal partons have been calculated, with next-to-leading order corrections through hard thermal loops (HTL) resummation

Bojko Bakalov, Nikolay M. Nikolov

Vertex algebras in higher dimensions provide an algebraic framework for investigating axiomatic quantum field theory with global conformal invariance. We develop further the theory of such vertex algebras by introducing formal calculus techniques and investigating the notion of polylocal fields. We derive a Jacobi identity which together with the vacuum axio

Beth A. Reid, David N. Spergel

The upcoming generation of SZE surveys will shed fresh light onto the study of clusters. What will this new observational window reveal about cluster properties? What can we learn from combining X-ray, SZE, and optical observations? How do variations in the gas entropy profile, dark matter concentration, accretion pressure, and intracluster medium (ICM) mass

Alex Gorodnik, Francois Maucourant, Hee Oh

Let X be the wonderful compactification of a connected adjoint semisimple group G defined over a number field K. We prove Manin&#39;s conjecture on the asymptotic (as T\to \infty) of the number of K-rational points of X of height less than T, and give an explicit construction of a measure on X(A), generalizing Peyre&#39;s measure, which describes the asympto

Peter Jung

In this article new bounds on weighted p-norms of ambiguity functions and Wigner functions are derived. Such norms occur frequently in several areas of physics and engineering. In pulse optimization for Weyl--Heisenberg signaling in wide-sense stationary uncorrelated scattering channels for example it is a key step to find the optimal waveforms for a given s

F. Herrmann, I. Hinder, D. Shoemaker, P. Laguna

We present results from fully nonlinear simulations of unequal mass binary black holes plunging from close separations well inside the innermost stable circular orbit with mass ratios q = M_1/M_2 = {1,0.85,0.78,0.55,0.32}, or equivalently, with reduced mass parameters $η=M_1M_2/(M_1+M_2)^2 = {0.25, 0.248, 0.246, 0.229, 0.183}$. For each case, the initial bin

Gorazd Cvetic, Cristian Valenzuela

We present two variants of an approach for evaluation of observables in analytic QCD models. The approach is motivated by the skeleton expansion in a certain class of schemes. We then evaluate the Adler function at low energies in one variant of this approach, in various analytic QCD models for the coupling parameter, and compare with perturbative QCD predic

Ta-Sheng Tai

We consider string theory on the Lorentzian Melvin geometry, which is obtained by analytically continuing the two-parameter Euclidean Melvin background. Because this model provides a solvable conformal field theory that describes time-dependent twisted string dynamics, we study the string one-loop partition function and the D-brane spectrum. We found that bo

H. Panagopoulos, A. Skouroupathis, A. Tsapalis

We calculate the perturbative value of the Free Energy in Lattice QCD in three dimensions, up to three loops. Our calculation is performed using the Wilson formulation for gluons in SU(N) gauge theories. The Free Energy is directly related to the average plaquette. To carry out the calculation, we compute the coefficients involved in the perturbative expansi

Richard D. Ball, Stefano Forte

We present a systematic formalism for the derivation of the kernel of the BFKL equation from that of the GLAP equation and conversely to any given order, with full inclusion of the running of the coupling. The running coupling is treated as an operator, reducing the inclusion of running coupling effects and their factorization to a purely algebraic problem.

Charles Bordenave

On a locally finite point set, a navigation defines a path through the point set from one point to another. The set of paths leading to a given point defines a tree known as the navigation tree. In this article, we analyze the properties of the navigation tree when the point set is a Poisson point process on $\mathbb{R}^d$. We examine the local weak converge

M Sepliarsky, M. G. Stachiotti, R. L. Migoni

Interface effects on the ferroelectric behavior of PbTiO$_3$ ultrathin films deposited on SrTiO$_3$ substrate are investigated using an interatomic potential approach with parameters fitted to first-principles calculations. We find that the correlation of atomic displacements across the film/substrate interface is crucial for the stabilization of the ferroel

Tobias Kaufmann, Lucio Mayer, James Wadsley, Joachim Stadel

We perform controlled N-Body/SPH simulations of disk galaxy formation by cooling a rotating gaseous mass distribution inside equilibrium cuspy spherical and triaxial dark matter halos. We systematically study the angular momentum transport and the disk morphology as we increase the number of dark matter and gas particles from 10^4 to 10^6, and decrease the g

Frédéric Chevy

We present a theoretical study of the density profile of a trapped strongly interacting Fermi gas with unbalanced spin populations. Making the assumption of the existence of a first order phase transition between an unpolarized superfluid phase and a fully polarized normal phase, we show good agreement with a recent experiment presented in Partridge et al.

V. Gnezdilov, K. -Y. Choi, Yu. Pashkevich, P. Lemmens

One- and multi-phonon excitations of the single crystalline LaCoO3 were studied using Raman spectroscopy in the temperature region of 5 K - 300 K. First-order Raman spectra show a larger number of phonon modes than allowed for the rhombohedral structure. Additional phonon modes are interpreted in terms of activated modes due to lattice distortions, arising f

P. T. O&#39;Brien, R. Willingale, J. Osborne, M. R. Goad

We present observations of the early X-ray emission for a sample of 40 gamma-ray bursts (GRBs) obtained using the Swift satellite for which the narrow-field instruments were pointed at the burst within 10 minutes of the trigger. Using data from the Burst Alert and X-Ray Telescopes, we show that the X-ray light curve can be well described by an exponential th

L. F. Wei, Yu-xi Liu, C. P. Sun, Franco Nori

We propose a spectroscopic approach to probe tiny vibrations of a nanomechanical resonator (NAMR), which may reveal classical or quantum behavior depending on the decoherence-inducing environment. Our proposal is based on the detection of the voltage-fluctuation spectrum in a superconducting transmission line resonator (TLR), which is {\it indirectly} couple

Matthias Scheid, Andreas Pfund, Dario Bercioux, Klaus Richter

We demonstrate that the combined effect of a spatially periodic potential, lateral confinement and spin-orbit interaction gives rise to a quantum ratchet mechanism for spin-polarized currents in two-dimensional coherent conductors. Upon adiabatic ac-driving, in the absence of a static bias, the system generates a directed spin current while the total charge

Abhas Mitra

By using elementary astrophysical concepts, we show that for any self-luminous astrophysical object, the ratio of radiation energy density inside the body (rho_r) and the baryonic energy density (rho_0) may be crudely approximated, in the Newtonian limit, as rho_r/rho_0 ~ GM/Rc^2, where G is constant of gravitation, c is the speed of light, M is gravitationa

Kazuharu Bamba, Motohiko Yoshimura

The possibility of the realization of a curvaton scenario is studied in a theory in which two dilatons are introduced along with coupling to the scalar curvature. It is shown that when the two dilatons have an approximate O(2) symmetric coupling, a scalar field playing the role of the curvaton may exist in the framework of this theory without introducing any

Guangtun Zhu, Zheng Zheng, W. P. Lin, Y. P. Jing

We study the dependence of the galaxy contents within halos on the halo formation time using two galaxy formation models, one being a semianalytic model utilizing the halo assembly history from a high resolution N-body simulation and the other being a smoothed particle hydrodynamics simulation including radiative cooling, star formation, and energy feedback

Yu-Ping Kuang

We review the developments of QCD multipole expansion and its applications to hadronic transitions and some radiative decays of heavy quarkonia. Theoretical predictions are compsred with updated experimental results.

H. Tsujimoto

It is found that the seesaw mechanism not only explains the smallness of neutrino masses but also accounts for the large mixing angles simultaneously, even if the unification of the neutrino Dirac mass matrix with that of up-type quark sector is realized. In this mechanism, we show that the mixing matrix of the Dirac-type mass matrix gets extra rotations fro

Sudhakar Panda, M. Sami, Shinji Tsujikawa, John Ward

We study inflation arising from the motion of a BPS D3-brane in the background of a stack of k parallel D5-branes. There are two scalar fields in this set up-- (i) the radion field R, a real scalar field, and (ii) a complex tachyonic scalar field chi living on the world volume of the open string stretched between the D3 and D5 branes. We find that inflation

Ryo Takahashi, Morimitsu Tanimoto

We discuss about the speed of sound squared in the Mass Varying Neutrinos scenario (MaVaNs). Recently, it was argued that the MaVaNs has a catastrophic instability which is the emergence of an imaginary speed of sound at the non-relativistic limit of neutrinos. As the result of this instability, the neutrino-acceleron fluid cannot act as the dark energy. How

Andrey Katz, Yael Shadmi, Yuri Shirman

We compute the one-loop correction to the radion potential in the Randall-Sundrum model with detuned brane tensions, with supersymmetry broken by boundary conditions. We concentrate on the small-warping limit, where the one-loop correction is significant. With pure supergravity, the correction is negative, but with bulk hypermultiplets, the correction can be

V. V. Flambaum

We show that the relative effect of variation of the fine structure constant in microwave transitions between very close and narrow rotational-hyperfine levels may be enhanced 2-3 orders of magnitude in diatomic molecules like LaS, LaO, LuS, YbF, etc. The enhancement is a result of cancellation between the hyperfine and rotational intervals.

Wei-Feng Tsai, Steven A. Kivelson

We present a controlled perturbative approach to the low temperature phase diagram of highly inhomogeneous Hubbard models in the limit of small coupling, $t&#39;$, between clusters. We apply this to the dimerized and checkerboard models. The dimerized model is found to behave like a doped semiconductor, with a Fermi-liquid groundstate with parameters ({\it e

Albert Schwarz

We show that the notions of space and time in algebraic quantum field theory arise from translation symmetry if we assume asymptotic commutativity. We argue that this construction can be applied to string theory.

Vesselin I. Marinov, Joel L. Lebowitz

We investigate the site percolation transition in two strongly correlated systems in three dimensions: the massless harmonic crystal and the voter model. In the first case we start with a Gibbs measure for the potential, $U=\frac{J}{2} \sum_{<x,y>} (ϕ(x) - ϕ(y))^2$, $x,y \in \mathbb{Z}^3$, $J > 0$ and $ϕ(x) \in \mathbb{R}$, a scalar height variable, and defi

Stephon H. S. Alexander

This research demonstrates that parity violation in general relativity can simultaneously explain the observed loss in power and alignment at a preferred axis (&#39;Axis of Evil&#39;)in the low multipole moments of the WMAP data. This observational possibility also provides an experimental window for an inflationary leptogenesis mechanism arising from large-

Thomas Chen

We consider a spin-$\frac12$ electron in a translation-invariant model of non-relativistic Quantum Electrodynamics (QED). Let $H(\vp,\sig)$ denote the fiber Hamiltonian corresponding to the conserved total momentum $\vp\in\R^3$ of the Pauli electron and the photon field, regularized by a fixed ultraviolet cutoff in the interaction term, and an infrared regul

Wen-ling Huang, Xiao Zhang

In a vacuum spacetime equipped with the Bondi&#39;s radiating metric which is asymptotically flat at spatial infinity including gravitational radiation ({\bf Condition D}), we establish the relation between the ADM total energy-momentum and the Bondi energy-momentum for perturbed radiative spatial infinity. The perturbation is given by defining the &#34;real