November 2005 arXiv papers — page 36

Jesper Fevre Bertelsen, Klaus Molmer

We present a theoretical model for formation of molecules in an optical lattice well where a resonant coupling of atomic and molecular states is provided by small oscillations of a magnetic field in the vicinity of a Feshbach resonance. As opposed to an adiabatic sweep over the full resonance, this provides a coherent coupling with a frequency that can be tu

Natalya A. Zimbovskaya

In the present work we theoretically analyze the effect of the Fermi surface local geometry on quantum oscillations in the velocity of an acoustic wave travelling in metal across a strong magnetic field. We show that local flattenings of the Fermi surface could cause significant amplification of quantum oscillations. This occurs due to enhancement of commens

C. Enkrich, M. Wegener, S. Linden, S. Burger

Arrays of gold split-rings with 50-nm minimum feature size and with an LC resonance at 200-THz frequency (1500-nm wavelength) are fabricated. For normal incidence conditions, they exhibit a pronounced fundamental magnetic mode, arising from a coupling via the electric component of the incident light. For oblique incidence, a coupling via the magnetic compone

Dmitry L. Kovrizhin, G. Venketeswara Pai, Subhasis Sinha

Motivated by the recent experiment on the Bose-Einstein condensation of $^{52}$Cr atoms with long-range dipolar interactions (Werner J. et al., Phys. Rev. Lett., 94 (2005) 183201), we consider a system of bosons with repulsive nearest and next-nearest neighbor interactions in an optical lattice. The ground state phase diagram, calculated using the Gutzwiller

C. J. Stockdale, L. A. Maddox, J. J. Cowan, A. Prestwich

We report the results of 15 years of radio observations of the six historical supernovae (SNe) in M83 using the Very Large Array. We note the near linear decline in radio emission from SN 1957D, a type II SN, which remains a non-thermal radio emitter. The measured flux densities from SNe 1923A and 1950B have flattened as they begin to fade below detectable l

Marc Moniez

The OSER project (Optical Scintillation by Extraterrestrial Refractors) is proposed to search for scintillation of extragalactic sources through the galactic -- disk or halo -- transparent $\mathrm{H\_2}$ clouds, the last unknown baryonic structures. This project should allow one to detect column density stochastic variations in cool Galactic molecular cloud

J. F. Macias-Perez, A. Bourrachot, the ARCHEOPS Collaboration

We present an alternative analysis of CMB time ordered data (TOD) using a wavelet-based representation of the data time-frequency plane. We demonstrate that the wavelet transform decorrelates $1/f$-type Gaussian stationary noise and permits a simple and functional description of locally stationary processes. In particular, this makes possible the generalizat

Edward W. Kolb, Antonio Riotto, Alberto Vallinotto

Recently we studied inflation models in which the inflaton potential is characterized by an underlying approximate global symmetry. In the first work we pointed out that in such a model curvature perturbations are generated after the end of the slow-roll phase of inflation. In this work we develop further the observational implications of the model and compu

Eric V. Linder

We present some useful ways to visualize the nature of dark energy and the effects of the accelerating expansion on cosmological quantities. Expansion probes such as Type Ia supernovae distances and growth probes such as weak gravitational lensing and the evolution of large scale structure provide powerful tests in complementarity. We present a ``ladder'

Sangeeta Malhotra, James Rhoads

The observed number density of Lyman-alpha sources implies a minimum volume of the inter-galactic medium that must be ionized, in order to allow the Lyman-alpha photons to escape attenuation. We estimate this volume by assigning to each Lyman-alpha emitter the minimum Stromgren sphere that would allow half its Lyman-alpha photons to escape. This implies a lo

J. Patrick Henry, Christopher R. Mullis, Wolfgang Voges, Hans Boehringer

The sky around the North Ecliptic Pole (NEP), at $α$(2000) = 18$^h00^m00^s$, $δ$(2000) = +66\degr33\arcmin39\arcsec, has the deepest exposure of the entire {\it ROSAT} All - Sky Survey (RASS). The NEP is an undistinguished region of moderate Galactic latitude, $b=29\fdg8$, and hence suitable for compiling statistical samples of both galactic and extragalacti

J. Pruet, R. D. Hoffman, S. E. Woosley, H. -T. Janka

One of the outstanding unsolved riddles of nuclear astrophysics is the origin of the so called ``p-process'' nuclei from A = 92 to 126. Both the lighter and heavier p-process nuclei are adequately produced in the neon and oxygen shells of ordinary Type II supernovae, but the origin of these intermediate isotopes, especially 92,94Mo and 96,98Ru, has l

M. H. Pinsonneault, K. Z. Stanek

The recent sample of 21 detached eclipsing binaries in the Small Magellanic Cloud (Harries et al. 2003, Hilditch et al. 2005) provides a valuable test of the binary mass function for massive stars. We show that 50% of detached binaries have companions with very similar masses, q=M_2/M_1 > 0.87, where M_1, M_2 denote the masses of the two binary components, M

L. Boirin, M. Diaz Trigo, M. Mendez, A. N. Parmar

Until now, the spectral changes observed from persistent to dipping intervals in dipping low-mass X-ray binaries were explained by invoking progressive and partial covering of an extended emission region. Here, we propose a novel and simpler way to explain these spectral changes, which does not require any partial covering and hence any extended corona, and

Ole Moeller, Edo Noordermeer

In this paper the expected properties of the velocity fields of strongly lensed arcs behind galaxy clusters are investigated. The velocity profile along typical lensed arcs is determined by ray tracing light rays from a model source galaxy through parametric cluster toy-models consisting of individual galaxies embedded in a dark cluster halo. We find that st

Enrique Perez-Montero, Angeles I. Diaz, Jose M. Vilchez, Carolina Kehrig

We have derived an empirical calibration of the abundance of S/H as a function of the S23 parameter, defined using the bright sulphur lines of [SII] and SIII]. Contrary to what is the case for the widely used O$_{23}$ parameter, the calibration remains single valued up to the abundance values observed in the disk HII regions. The calibration is based on a la

Francesco Polcaro, Andrea Martocchia

The supernova explosion of 1054 AD, which originated the Crab Nebula and Pulsar, is probably the astronomical event which has been most deeply studied by means of historical sources. However, many mysteries and inconsistencies, both among the different sources and between what is deduced by the historical records and the present day astronomical data, are de

Andrea Tiengo, Sandro Mereghetti

Scattering by interstellar dust grains can produce time variable X-ray halos around gamma-ray bursts (GRB). In particular, an X-ray expanding ring is expected when a short pulse of X-ray radiation is scattered by a narrow layer of dust in our Galaxy. We present a new method to detect and analyze dust scattering expanding rings around gamma-ray bursts, using

A. De Luca, P. A. Caraveo, F. Mattana, A. Pellizzoni

A deep (100 ks) XMM-Newton observation of Geminga has shown two faint tails of diffuse X-ray emission, extending for ~2' behind the pulsar, well aligned with the proper motion (PM) direction. We report here on a recent ~20 ks Chandra observation, which unveils a new structure, ~25'' long and ~5'' thick, starting at the pulsar position and

M. Pierre, F. Pacaud, the XMM-LSS consortium

We present the X-ray source detection procedure that we have developed for the purpose of assembling and characterizing controlled samples of cluster of galaxies for the XMM Large Scale Structure Survey. We describe how we model the selection function by means of simulations: this leads us to define source classes rather than flux limited samples. Focussing

N. Masetti, E. Mason, L. Bassani, A. J. Bird

We present the results of our optical spectrophotometric campaign ongoing at the Astronomical Observatory of Bologna in Loiano (Italy) on hard X-ray sources detected by INTEGRAL. We observed spectroscopically the putative optical counterparts of four more INTEGRAL sources, IGR J12391-1610, IGR J18406-0539, 2E 1853.7+1534 and IGR J19473+4452. These data have

S. G. Rubin

Black hole formation in the framework of hybrid inflation is considered. It is shown that this model of inflation provides conditions for multiple black hole production.

G. F. Porto de Mello, E. F. del Peloso, L. Ghezzi

The existence of life based on carbon chemistry and water oceans relies upon planetary properties, chiefly climate stability, and stellar properties, such as mass, age, metallicity and Galactic orbits. The latter can be well constrained with present knowledge. We present a detailed, up-to-date compilation of the atmospheric parameters, chemical composition,

A. D. Kaminker, M. E. Gusakov, D. G. Yakovlev, O. Y. Gnedin

We study the "minimal" cooling scenario of superfluid neutron stars with nucleon cores, where the direct Urca process is forbidden and the enhanced cooling is produced by the neutrino emission due to Cooper pairing of neutrons. Extending our previous consideration (Gusakov et al. 2004a), we include the effects of accreted envelopes of light elements.

G. Weigelt, H. Beuther, K. -H. Hofmann, M. R. Meyer

We present bispectrum speckle interferometry of the massive protostellar object IRAS 23151+5912 in the near-infrared K' band. The reconstructed image shows the diffuse nebulosity north-east of two point-like sources in unprecedented detail. The comparison of our near-infrared image with mm continuum and CO molecular line maps shows that the brighter of t

Carla Maceroni

The study of binary stars is worth to undertake not only to learn more about the properties of binaries as such, but also because binaries are multi-purpose astrophysical tools. This paper reviews some of the ways this effective "tool" can be used, focusing on fundamental parameter determination, tests of theoretical models, and the recent contributi

W. J. de Wit, J. Bouvier, F. Palla, J. -C. Cuillandre

We present a study of the young (30-100Myr) open cluster IC 4665 with the aim to determine the shape of the mass function well into the brown dwarf regime. We photometrically select 691 low-mass stellar and 94 brown dwarf candidate members over an area of 3.82 square degrees centred on the cluster. K-band follow-up photometry and Two-Micron All-Sky Survey da

G. Gräfener, W. -R. Hamann

With the advance of stellar atmosphere modelling during the last few years, large progress in the understanding of Wolf-Rayet (WR) mass loss has been achieved. In the present paper we review the most recent developments, including our own results from hydrodynamic non-LTE model atmospheres. In particular, we address the important question of the Z-dependence

E. M. Berkhuijsen, D. Mitra, P. Mueller

The combination of dispersion measures of pulsars, distances from the model of Cordes and Lazio (2002) and emission measures from the WHAM survey enabled a statistical study of electron densities and filling factors of the diffuse ionized gas (DIG) in the Milky Way. The emission measures were corrected for absorption and contributions from beyond the pulsar

Carla Maceroni, Ignasi Ribas

The space experiment CoRoT will provide continuous monitoring and high accuracy light curves of about sixty thousand stars. Selected binary systems will be observed in the Additional Program frame as targets of long and continuous pointed observations. Moreover, thousands of new binaries will certainly be detected and hundreds of them will have extremely acc

Akira Imada, L. A. G. Berto Monard

We report on time-resolved CCD photometry during the 2005 June outburst of a dwarf nova, ASAS160048-4846.2. The observed light curves unambiguously showed embryonic humps with a period of 0.063381(41) days, after which genuine superhumps emerged with a period of 0.064927(3) days. Based on evidence for double-peaked humps in the earlier stage of the outburst,

B. Stelzer, G. Micela, E. Flaccomio, R. Neuhaeuser

Three brown dwarfs in different evolutionary stages have been observed with the Chandra X-ray Observatory. Combining the new observations with previous studies presented in the literature yields a brown dwarf sample that reaches well down into the cooling phase of brown dwarfs, allowing to investigate the possible influence of effective temperature on X-ray

J. A. Caballero

The nearby young sigma Orionis cluster (~360 pc, ~3 Ma) is becoming one of the most important regions for the study of ultra low-mass star formation and its extension down to the mass regimes of the brown dwarfs and planetary-mass objects. Here, I introduce the sigma Orionis cluster and present three studies that the JOVIAN group is developing: a pilot progr

J. Ren, Xin He Meng

A generally parameterized equation of state (EOS) is investigated in the cosmological evolution with bulk viscosity media modelled as dark fluid, which can be regarded as a unification of dark energy and dark matter. Compared with the case of the perfect fluid, this EOS has possessed four additional parameters, which can be interpreted as the case of the non

Yan Liu, Xiang-Qian Luo

We compute from quenched lattice QCD the ground state masses of the charmed hybrid mesons cbar c g, with exotic quantum numbers JPC=1-+, 0+- and 0--. The 0-- hybrid meson spectrum has never been provided by lattice simulations due to the difficulties to extract high gluonic excitations from noise. We employ improved gauge and fermion actions on the anisotrop

J. B. Conrey, D. W. Farmer, M. R. Zirnbauer

For the classical compact Lie groups K = U(N) the autocorrelation functions of ratios of random characteristic polynomials are studied. Basic to our treatment is a property shared by the spinor representation of the spin group with the Shale-Weil representation of the metaplectic group: in both cases the character is the analytic square root of a determinant

F. Deppisch, H. Päs, R. Rückl, A. Redelbach

We study the constraints on a minimal supersymmetric seesaw model imposed by neutrino data, charged lepton flavor violation, thermal leptogenesis and perturbativity. We show that it is possible to constrain the three heavy Majorana neutrino masses as well as the complex Yukawa coupling matrix. Our results provide a first step towards a seesaw benchmark model

Hyundong Shin, Moe Z. Win

The potential benefits of multiple-antenna systems may be limited by two types of channel degradations rank deficiency and spatial fading correlation of the channel. In this paper, we assess the effects of these degradations on the diversity performance of multiple-input multiple-output (MIMO) systems, with an emphasis on orthogonal space-time block codes, i

Mustafa Salti, Oktay Aydogdu

This paper has been removed by arXiv administrators because it overlaps gr-qc/0102077 and others. This paper also has excessive overlap with the following papers also written by the authors or their collaborators: gr-qc/0603027, gr-qc/0606022, gr-qc/0512080, gr-qc/0603108, gr-qc/0601141, gr-qc/0603063, gr-qc/0608050, gr-qc/0607095, gr-qc/0607011, gr-qc/06070

Qing-hua Xu, Zuo-tang Liang, Ernst Sichtermann

We study the polarization of the anti-Lambda particle in polarized high energy pp collisions at large transverse momenta. The anti-Lambda polarization is found to be sensitive to the polarization of the anti-strange sea of the nucleon. We make predictions using different parameterizations of the polarized quark distribution functions. The results show that t

A. Broadbent, A. A. Methot

Recently, a number of two-participant all-versus-nothing Bell experiments have been proposed. Here, we give local realistic explanations for these experiments. More precisely, we examine the scenario where a participant swaps his entanglement with two other participants and then is removed from the experiment; we also examine the scenario where two particles

Alexei Kovalev

A class of examples of Riemannian metrics with holonomy G_2 on compact 7-manifolds was constructed by the author in arXiv:math.DG/0012189 and later in a joint work with N.-H. Lee in arXiv:0810.0957, using a certain `generalized connected sum' of two asymptotically cylindrical manifolds with holonomy SU(3). We consider, on each of the two initial SU(3)-manifo

Tom H. Koornwinder

This article gives a brief introduction to $q$-special functions, i.e., $q$-analogues of the classical special functions. Here $q$ is a deformation parameter, usually $0<q<1$, where $q=1$ is the classical case. The main topics to be treated are $q$-hypergeometric series, with some selected evaluation and transformation formulas, and the $q$-hypergeometric or

A. Kartavtsev

Baryon and lepton numbers of the Universe in leptogenesis with Dirac neutrino and leptogenesis with Majorana neutrino scenarios are considered. It is shown that despite quite different features of Dirac and Majorana fermions both scenarios yield the same relation among the initial lepton and the final baryon asymmetries. Moreover right-handed neutrinos in th

Marco Frasca

We analyze numerically a two-dimensional $λϕ^4$ theory showing that in the limit of a strong coupling $λ\to\infty$ just the homogeneous solutions for time evolution are relevant in agreement with the duality principle in perturbation theory as presented in [M.Frasca, Phys. Rev. A {\bf 58}, 3439 (1998)], being negligible the contribution of the spatial varyin

Marek Gazdzicki, Mark Gorenstein

We propose to use the hadron number fluctuations in the limited momentum regions to study the evolution of initial flows in high energy nuclear collisions. In this method by a proper preparation of a collision sample the projectile and target initial flows are marked in fluctuations in the number of colliding nucleons. We discuss three limiting cases of the

J. R. Brownstein, J. W. Moffat

A fully relativistic modified gravitational theory including a fifth force skew symmetric field is fitted to the Pioneer 10/11 anomalous acceleration. The theory allows for a variation with distance scales of the gravitational constant G, the fifth force skew symmetric field coupling strength omega and the mass of the skew symmetric field mu=1/lambda. A fit

William P. Orrick

Two matrices with elements taken from the set {-1,1} are Hadamard equivalent if one can be converted into the other by a sequence of permutations of rows and columns, and negations of rows and columns. In this paper we summarize what is known about the number of equivalence classes of matrices having maximal determinant. We establish that there are 7 equival

John Gough

We discuss stochastic derivations, stochastic Hamiltonians and the flows that they generate, algebraic fluctuaion-dissipation theorems, etc., in a language common to both classical and quantum algebras. It is convenient to define distinct notions of time-ordered exponentials to take account of the breakdown of the Leibniz rule in the Ito calculus. We introdu

G. Van Hooydonk

Ab initio quantum chemistry reveals how the charge-antisymmetric antihydrogenic antiHH+ state, deriving from conventional positional antisymmetry of a 3-unit charge system, is hidden in the PEC (potential energy curve) of the molecular hydrogen cation. Only with internal charge inversion and Coulomb&#39;s law, the anti-symmetry generated by positional coordi

Bernhard Rothenstein, Doru Paunescu

We investigate the conditions under which computer programs represent correctly, in polar coordinates, the relativistic transformation equations for the space-time coordinates of the same event.

P. Maris, P. C. Tandy

We review recent developments in the understanding of meson properties as solutions of the Bethe-Salpeter equation in rainbow-ladder truncation. Included are recent results for the pseudoscalar and vector meson masses and leptonic decay constants, ranging from pions up to c\bar{c} bound states; extrapolation to b\bar{b} states is explored. We also present a

Paul Kersten, Iosif Krasil&#39;shchik, Alexander Verbovetsky

We discuss the dispersionless Boussinesq type equation, which is equivalent to the Benney-Lax equation, being a system of equations of hydrodynamical type. This equation was discussed in <http://dx.doi.org/doi:10.1088/0305-4470/27/1/013>. The results include: a description of local and nonlocal Hamiltonian and symplectic structures, hierarchies of symmetries

Christian Korff

Taking the isotropic limit in a recent representation theoretic construction of Baxter&#39;s Q-operators for the XXZ model with quasi-periodic boundary conditions we obtain new results for the XXX model. We show that quasi-periodic boundary conditions are needed to ensure convergence of the Q-operator construction and derive a quantum Wronskian relation whic

Dorin Ervin Dutkay

The local trace function introduced in \cite{Dut} is used to derive equations that relate multiwavelets and multiscaling functions in the context of a generalized multiresolution analysis, without appealing to filters. A construction of normalized tight frame wavelets is given. Particular instances of the construction include normalized tight frame and ortho

Peter A. B. Pleasants, Michael Baake, Johannes Roth

The coincidence problem for planar patterns with $N$-fold symmetry is considered. For the N-fold symmetric module with $N<46$, all isometries of the plane are classified that result in coincidences of finite index. This is done by reformulating the problem in terms of algebraic number fields and using prime factorization. The more complicated case $N \ge 46$

Amir Mafi

Let $R$ be a commutative Noetherian ring, $\fa$ an ideal of $R$, $M$ and $N$ be two finitely generated $R$-modules. Let $t$ be a positive integer. We prove that if $R$ is local with maximal ideal $\fm$ and $ M\otimes_R N$ is of finite length then $H_{\fm}^t(M,N)$ is of finite length for all $t\geq 0$ and $l_R(H_{\fm}^t (M,N))\leq \sum_{i=0}^t l_R(\Ext_R^i(M,

Jeb F. Willenbring

Given a classical symmetric pair, $(G,K)$, with $\mathfrak g = Lie(G)$, we provide descriptions of the Hilbert series of the algebra of $K$-invariant vectors in the associated graded algebra of $\mathcal U(\mathfrak g)$ viewed as a $K$-representation under restriction of the adjoint representation. The description illuminates a certain stable behavior of the

Roger E. Howe, Eng Chye Tan, Jeb F. Willenbring

This paper focuses on the $GL_n$ tensor product algebra, which encapsulates the decomposition of tensor products of arbitrary finite dimensional irreducible representations of $GL_n$. We will describe an explicit basis for this algebra. This construction relates directly with the combinatorial description of Littlewood-Richardson coefficients in terms of Lit

Roger E. Howe, Eng Chye Tan, Jeb F. Willenbring

We study branching laws for a classical group $G$ and a symmetric subgroup $H$. Our approach is through the {\it branching algebra}, the algebra of covariants for $H$ in the regular functions on the natural torus bundle over the flag manifold for $G$. We give concrete descriptions of (natural subalgebras of) the branching algebra using classical invariant th

Michael Kapovich, Bernhard Leeb, John J. Millson

As in a symmetric space of noncompact type, one can associate to an oriented geodesic segment in a Euclidean building a vector valued length in the Euclidean Weyl chamber; in addition to the metric length it contains information on the direction of the segment. We study in this paper restrictions on the vector valued side lengths of polygons in (thick) Eucli

Misha Kapovich, Bernhard Leeb, John J. Millson

In a symmetric space of noncompact type X = G/K oriented geodesic segments correspond to points in the Euclidean Weyl chamber. We can hence assign vector-valued side-lengths to segments. Our main result is a system of homogeneous linear inequalities describing the restrictions on the side -lengths of closed polygons. The inequalities are based on the mod 2 S

Roger E. Howe, Eng Chye Tan, Jeb F. Willenbring

We approach the problem of obtaining branching rules from the point of view of dual reductive pairs. Specifically, we obtain a stable branching rule for each of 10 classical families of symmetric pairs. In each case, the branching multiplicities are expressed in terms of Littlewood-Richardson coefficients. Some of the formulas are classical and include, for

Joshua Feinberg, Shlomi Hillel

Formation of fermion bag solitons is an important paradigm in the theory of hadron structure. We report here on our non-perturbative analysis of this phenomenon in the 1+1 dimensional massive Gross-Neveu model, in the large $N$ limit. Our main result is that the extremal static bag configurations are reflectionless, as in the massless Gross-Neveu model. Expl

M. A. Rajabpour, S. Moghimi-Araghi

In this letter we investigate the finite size scaling effect on SLE($κ,ρ$) and boundary conformal field theories and find the effect of fixing some boundary conditions on the free energy per length of SLE($κ,ρ$). As an application, we will derive the entanglement entropy of quantum systems in critical regime in presence of boundary operators.

Amihay Hanany, David Vegh

We describe a simple algorithm that computes the recently discovered brane tilings for a given generic toric singular Calabi-Yau threefold. This therefore gives AdS/CFT dual quiver gauge theories for D3-branes probing the given non-compact manifold. The algorithm solves a longstanding problem by computing superpotentials for these theories directly from the

Oliver Schnetz, Michael Thies, Konrad Urlichs

The massive Gross-Neveu model is solved in the large N limit at finite temperature and chemical potential. The phase diagram features a kink-antikink crystal phase which was missed in previous works. Translated into the framework of condensed matter physics our results generalize the bipolaron lattice in non-degenerate conducting polymers to finite temperatu

Gregory Gabadadze, Yanwen Shang

We study gauge and gravitational field theories in which the gauge fixing conditions are imposed as constraints on classical fields. Quantization of fluctuations can be performed in a BRST invariant manner, while the main novelty is that the classical equations of motion admit solutions that are not present in the standard approach. Although the new solution

E. Gotsman, E. Levin, U. Maor, E. Naftali

Our presentation centers on the consequences of s-channel unitarity, manifested by soft re-scatterings of the spectator partons in a high energy diffractive process, focusing on the calculations of gap survival probabilities. Our emphasis is on recent estimates relevant to exclusive diffractive Higgs production at the LHC. To this end, we critically re-exami

Martin W. Grunewald

Recent published and preliminary precision electroweak measurements are reviewed, including new results on the mass of the top quark and mass and width of the W boson. The experimental results are compared with the predictions of the Standard Model and are used to constrain its free parameters, notably the mass of the Higgs boson. The agreement between measu

R. Aloisio, A. Galante, A. Grillo, S. Liberati

In this article we elaborate on a recently proposed interpretation of DSR as an effective measurement theory in the presence of non-negligible (albeit small) quantum gravitational fluctuations. We provide several heuristic arguments to explain how such a new theory can emerge and discuss the possible observational consequences of this framework.

Necmi Bugdayci

Global monochromatic solutions of the scalar wave equation are obtained in flat wormholes of dimensions 2+1 and 3+1. The solutions are in the form of infinite series involving cylindirical and spherical wave functions and they are elucidated by the multiple scattering method. Explicit solutions for some limiting cases are illustrated as well. The results pre

Muraari Vasudevan

In this note, we study the integrability of geodesic flow in the background of a very general class of spacetimes with NUT-charge(s) in higher dimensions. This broad set encompasses multiply NUT-charged solutions, electrically and magnetically charged solutions, solutions with a cosmological constant, and time dependant bubble-like solutions. We also derive

Suresh K Maran

The Spin Foam Model for the SO(4,C) BF theory is discussed. The Barrett-Crane intertwiner for the SO(4,C) general relativity is systematically derived. The SO(4,C) Barret-Crane interwiner is unique. The propagators of the SO(4,C) Barrett-Crane model are discussed. The asymptotic limit of the SO(4,C) general relativity is discussed. The asymptotic limit is co

J. A. Belinchón

In this paper, we study the equation of state admissible for a flat FRW models filled with a bulk viscous fluid by using the Lie group method. It is founded that the model admits scaling symmetries iff the bulk viscous parameter $γ=1/2$. In this case, it is found that the main quantities follow a power law solution and in particular the bulk viscous pressure

P. G. Miedema, W. A. van Leeuwen

We propose a way to construct manifestly gauge independent quantities out of the gauge dependent quantities occurring in the linearized Einstein equations. Thereupon, we show that these gauge-invariant combinations can be identified with measurable perturbations to the particle and energy densities. In the radiation-dominated era we find, for small-scale per

Aditya Mahajan, Demosthenis Teneketzis

We consider a communication system in which the outputs of a Markov source are encoded and decoded in \emph{real-time} by a finite memory receiver, and the distortion measure does not tolerate delays. The objective is to choose designs, i.e. real-time encoding, decoding and memory update strategies that minimize a total expected distortion measure. This is a

K. Yu. Bliokh

Comment on S.-Q. Shen, Phys. Rev. Lett. 95, 187203 (2005) [cond-mat/0506676]. We show that the equations of motion deduced by Shen are incorrect and derive semiclassical expression for the operator of force, which also contains a term of the transverse spin force but twice as large in magnitude.

T. Masuda, A. Zheludev, H. Manaka, L. -P. Regnault

Magnetic excitations in the quasi-one-dimensional antiferromagnet IPA-CuCl3 are studied by cold neutron inelastic scattering. Strongly dispersive gap excitations are observed. Contrary to previously proposed models, the system is best described as an asymmetric quantum spin ladder. The observed spectrum is interpreted in terms of ``composite&#39;&#39; Haldan

James F. Lutsko

The Chapman-Enskog method of solution of kinetic equations, such as the Boltzmann equation, is based on an expansion in gradients of the deviations fo the hydrodynamic fields from a uniform reference state (e.g., local equilibrium). This paper presents an extension of the method so as to allow for expansions about \emph{arbitrary}, far-from equilibrium refer

Kevin Krisciunas, Jose Luis Prieto, Peter M. Garnavich, Jessica-Lynn G. Riley

We present previously unpublished BVRI photometry of the Type Ia supernovae 1999cc and 2000cf along with revised photometry of SN 1999cl. We confirm that SN 1999cl is reddened by highly non-standard dust, with R_V = 1.55 +/- 0.08. Excepting two quasar-lensing galaxies whose low values of R_V are controversial, this is the only known object with a published v

James E. Lidsey, David Seery

Observational consequences of inflationary cosmology in the holographic dual of the Randall-Sundrum type II braneworld scenario, as motivated by the AdS/CFT correspondence, are investigated. High energy corrections to the standard four-dimensional Friedmann equation induce a corresponding modification to the form of the single-field inflationary consistency

R. Nordon, E. Behar, M. Guedel

The RSCVn system Sigma Geminorum was observed by XMM-Newton on April 2001 during a large flare. We model the emission measure distribution (EMD) during the flare and during a quiescence period. In the flare, a two phase behaviour is found in which the cool plasma (kT < 2 keV) is not disturbed while a large hot component, at temperatues of kT > 3 keV emerges.

Johan Holmberg, Chris Flynn, Laura Portinari

We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the UV to the near-IR). A crucial improvement is that the effective temperature scale of the stars has recently been established as both accurate and precise through direct measurement of angular diameters obtained with stellar interferometers. We fit

Luis C. Ho

It is now widely believed that the growth of massive black holes is closely linked to the formation of galaxies, but there have been few concrete constraints on the actual physical processes responsible for this coupling. Investigating the connection between AGN and starburst activity may offer some empirical guidance on this problem. I summarize previous ob

Michael P. Salem

Recently a mechanism was proposed whereby the primordial density perturbations are generated at the end of inflation. We continue the analysis of the proposed model of this mechanism and calculate the maximum extent to which the density perturbations produced via this model can dominate over those of the standard inflationary paradigm. In addition, we provid

E. Mukhin, A. Varchenko

For $r\in \Z_{\geq 0}$, we present a linear differential operator %$(\di)^{r+1}+ a_1(x)(\di)^{r}+...+a_{r+1}(x)$ of order $r+1$ with rational coefficients and depending on parameters. This operator annihilates the $r$-multiple Jacobi-Piñeiro polynomial. For integer values of parameters satisfying suitable inequalities, it is the unique Fuchsian operator with

Luc Bouten, Ramon van Handel

It is well known that quantum continuous observations and nonlinear filtering can be developed within the framework of the quantum stochastic calculus of Hudson-Parthasarathy. The addition of real-time feedback control has been discussed by many authors, but the foundations of the theory still appear to be relatively undeveloped. Here we introduce the notion

Kazumi Okuyama

We propose that in the BMN limit the effective interaction vertex in the 1/2 BPS sector of N=4 SYM is given by the Das-Jevicki-Sakita Hamiltonian. We check for some examples that it reproduces the 1/N correction to the correlation functions of 1/2 BPS operators.

Kiran S. Kedlaya, Daniel Gulotta

Bhargava has given a formula, derived from a formula of Serre, computing a certain count of extensions of a local field, weighted by conductor and by number of automorphisms. We interpret this result as a counting formula for permutation representations of the absolute Galois group of the local field, then speculate on variants of this formula in which the r

Sergey Nazarenko

I present a nonlinear differential equation model (DAM) for the spectrum of Kelvin waves on a thin vortex filament. This model preserves the original scaling of the six-wave kinetic equation, its direct and inverse cascade solutions, as well as the thermodynamic equilibrium spectra. Further, I extend DAM to include the effect of sound radiation by Kelvin wav

D. M. Wei, T. Yan, Y. Z. Fan

GRB050904 is very interesting since it is by far the most distant GRB event known to date($z=6.29$). It was reported that during the prompt high energy emission phase, a very bright optical flare was detected, and it was temporal coincident with an X-ray flare. Here we use two models to explain the optical flare, One is the &#34;late internal shock model&#34

A. I. Lvovsky, M. G. Raymer

This review covers latest developments in continuous-variable quantum-state tomography of optical fields and photons, placing a special accent on its practical aspects and applications in quantum information technology. Optical homodyne tomography is reviewed as a method of reconstructing the state of light in a given optical mode. A range of relevant practi

J. F. McMillan, X. Yang, N. C. Panoiu, R. M. Osgood

We investigate for the first time the enhancement of the stimulated Raman scattering in slow-light Silicon-on-Insulator (SOI) photonic crystal line defect waveguides. By applying the Bloch-Floquet formalism to the guided modes in a planar photonic crystal, we develop a formalism that relates the intensity of the down-shifted Stokes signal to the pump intensi

I. V. Moskalenko, T. A. Porter, A. W. Strong

The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with multi-wavelength observations by DIRBE and FIRAS indicates that the energy density of the Galactic interstellar radiation field is

Renat Kh. Gainutdinov, Aigul A. Mutygullina

Problems connected with non-Hamiltonian nature of low energy nucleon dynamics in the effective field theory (EFT) of nuclear forces is investigated by using the formalism of the generalized quantum dynamics (GQD) developed in [J. Phys. A, 5657 (1999)]. This formalism is based on a generalized dynamical equation derived as the most general equation of motion

Liane Gabora, Diederik Aerts

It is increasingly evident that there is more to biological evolution than natural selection; moreover, the concept of evolution is not limited to biology. We propose an integrative framework for characterizing how entities evolve, in which evolution is viewed as a process of context-driven actualization of potential (CAP). Processes of change differ accordi

Gordon Chalmers

A Matlab program is presented that computes derivative corrections in the S-dual invariant formulation for IIB graviton scattering to any order in perturbation theory. The coefficients of the four-point function are produced, pertaining to the non-logarithmic terms. The program can be modified to find coefficients of the higher-point functions. Instantons ha

Christian Schulze, Dietrich Stauffer

Following Abrams and Strogatz 2003 and Patriarca and Leppanen 2004, five other physics groups independently started to simulate the competition of languages, as opposed to the evolution of a human language out of ape sounds, or the learning of a language by a child. This talk concentrates on the models of Christian Schulze et al and of Viviane de Oliveira et

Germain Rousseaux

Based on an analogy between Fluid Mechanics and Electromagnetism, we claim that the gauge conditions of Classical Electromagnetism are not equivalent contrary to the common belief. These &#34;gauges&#34; are usually considered as mathematical conditions that one must specify in order to solve any electromagnetic problem. Here, the author shows that these con