May 2001 arXiv papers — page 4

H. -W. Hammer, Thomas Mehen

We calculate the range corrections to S-wave neutron-deuteron scattering in the doublet channel (S=1/2) to first order in r/a where a is the scattering length and r the effective range. Ultraviolet divergences appearing at this order can be absorbed into a redefinition of the leading order three-body force. The corrections to the elastic scattering amplitude

B. N. Kalinkin, F. A. Gareev

It is shown that it is just Dubna that possesses the priority both in the recent synthesis of a superheavy nucleus with charge Z = 114 (Flerov Laboratory of Nuclear Reactions, JINR) and in its theoretical prediction (Bogoliubov Laboratory of Theoretical Physics, JINR) made 33 years ago. Possible sizes of the island of stability of superheavy nuclei are discu

Rainer E. Zimmermann

Recent developments in loop quantum gravity and topological quantum field theory are being mirrored with a view to the emergent structure of self- organized criticality (SOC). Referring back to an earlier paper [nlin.AO/ 0105064], the relationship of SOC to negator algebra is discussed. It is shown that introducing the categorial perspective leads to further

Rainer E. Zimmermann, Wolfram Voelcker

We discuss aspects of emergence by introducing the concept of negator algebra referring to topos-theoretic results obtained by Vladimir Trifonov some time ago. As a possible application of this concept we present an example from non-linear economic processes concerning the evolution of the global crude oil market during the second half of the 20th century.

Kenichiro Aoki, Dimitri Kusnezov

We study how local equilibrium, and linear response predictions of transport coefficients are violated as systems move far from equilibrium. This is done by studying heat flow in classical lattice models with and without bulk transport behavior, in 1--3 dimensions. We see that linear response and local equilibrium assumptions break down at the same rate. The

Ale Jan Homburg, Todd Young

We discuss one parameter families of unimodal maps, with negative Schwarzian derivative, unfolding a saddle-node bifurcation. It was previously shown that for a parameter set of positive Lebesgue density at the bifurcation, the maps possess attracting periodic orbits of high period. We show that there is also a parameter set of positive density at the bifurc

James Allen Fill, Svante Janson

The number of comparisons X_n used by Quicksort to sort an array of n distinct numbers has mean mu_n of order n log n and standard deviation of order n. Using different methods, Regnier and Roesler each showed that the normalized variate Y_n := (X_n - mu_n) / n converges in distribution, say to Y; the distribution of Y can be characterized as the unique fixe

James Allen Fill, Svante Janson

The limiting distribution of the normalized number of comparisons used by Quicksort to sort an array of n numbers is known to be the unique fixed point with zero mean of a certain distributional transformation S. We study the convergence to the limiting distribution of the sequence of distributions obtained by iterating the transformation S, beginning with a

Kiran S. Kedlaya

Tsuzuki has conjectured that for crystals with Frobenius and connection over a local field k((t)), the embedding of the category of overconvergent crystals into the category of convergent crystals is fully faithful. We prove Tsuzuki's conjecture restricted to the subcategory of potentially semistable (or quasi-unipotent) crystals, following de Jong's

Laurent Manivel

We describe the generic singularity of a Schubert variety of type A on each irreducible component of its singular locus. This singularity is given either by a cone of rank one matrices, or a quadratic cone.

Thomas Scanlon

We note that Pillay's result on the stability of an algebraically closed field with a predicate for a group of Lang type implies that number uniformity follows formally from the finiteness results analogous to Faltings' Theorem.

Kiran S. Kedlaya

In this paper (part of the author's PhD thesis), we introduce the notions of semistability and potential semistability of overconvergent F-crystals over an equal characteristic local field. We establish their equivalence with the notions of unipotency and quasi-unipotency given by Crew, and to recast the conjecture that every overconvergent crystal is qu

R. Fioresi, A. Levrero, M. A. Lledó

In this paper we study a family of algebraic deformations of regular coadjoint orbits of compact semisimple Lie groups with the Kirillov Poisson bracket. The deformations are restrictions of deformations on the dual of the Lie algebra. We prove that there are non isomorphic deformations in the family. The star products are not differential, unlike the star p

Tien-Yien Li, J. Maurice Rojas, Xiaoshen Wang

We prove that any pair of bivariate trinomials has at most 5 isolated roots in the positive quadrant. The best previous upper bounds independent of the polynomial degrees counted only non-degenerate roots and even then gave much larger bounds, e.g., 248832 via a famous general result of Khovanski. Our bound is sharp, allows real exponents, and extends to cer

Khaled Abdel-Khalek

We give an explicit parameterization of the general 8k -3 instanton.

Eanna Flanagan, Richard J. Hill, Nicholas Jones, S. -H. Henry Tye

Recently a brane world perspective on the cosmological constant and the hierarchy problems was presented. Here, we elaborate on some aspects of that particular scenario and discuss the stability of the stationary brane solution and the dynamics of a probe brane. Even though the brane is unstable under a small perturbation from its stationary position, such i

M. Axenides, E. G. Floratos, L. Perivolaropoulos

We generalize recent study of the stability of isotropic (spherical) rotating membranes to the anisotropic ellipsoidal membrane. We find that while the stability persists for deformations of spin $l=1$, the quadrupole and higher spin deformations ($l\geq 2$) lead to instabilities. We find the relevant instability modes and the corresponding eigenvalues. Thes

S. V. Kryukov

The space of local integrals of motion for the Sine-Gordon theory (the free fermion point) and the theory of free fermions in the light cone coordinates is investigated. Some important differences between the spaces of local integrals of motion of these theories are obtained. The equivalence is broken on the level of the integrals of motion between bosonic a

Vladimir S. Dotsenko, Jesper Lykke Jacobsen, Marco Picco

We present a method for classifying conformal field theories based on Coulomb gases (bosonic free-field construction). Given a particular geometric configuration of the screening charges, we give necessary conditions for the existence of degenerate representations and for the closure of the vertex-operator algebra. The resulting classification contains, but

I. N. Nikitin, J. De Luca

We develop two numerical methods to solve the differential equations with deviating arguments for the motion of two charges in the action-at-a-distance electrodynamics. Our first method uses Stürmer's extrapolation formula and assumes that a step of integration can be taken as a step of light ladder, which limits its use to shallow energies. The second m

M. R. Setare, A. A. Saharian

We study the creation of massless scalar particles from the quantum vacuum due to the dynamical Casimir effect by spherical shell with oscillating radius. In the case of a small amplitude of the oscillation, to solve the infinite set of coupled differential equations for the instantaneous basis expansion coefficients we use the method based on the time-depen

Israel Quiros

A five-dimensional scenario with a non compact extra dimension of infinite extent is studied, in which a single three-brane is affected by small Gaussian fluctuations in the extra dimension. The average magnitude of the fluctuations is of order of the electro-weak length scale ($σ\sim m_{EW}^{-1}$). The model provides an stochastic approach to gravity that a

B. M. Barbashov, V. N. Pervushin

The time-reparametrization-invariant dynamics of a relativistic string is studied in the Dirac generalized Hamiltonian theory by resolving the first class constraints. The reparametrization-invariant evolution parameter is identified with the time-like coordinate of the "center of mass" of a string which is separated from local degrees of freedom by

Mikolaj Misiak

The experimental and theoretical status of the inclusive decay B -> X_s gamma is briefly summarized. Results from a very recent theoretical analysis are reported. An ~11% increase in the SM prediction for BR[ B -> X_s gamma] is found after replacing m_c^pole/m_b^pole by m_c(mu)/m_b^1S in the NLO QCD correction. The well-known enhancement of the branching rat

Loyal Durand

I present a simple discussion of the masses and mixings of the light pseudoscalar and vector mesons based on a ``$q\bar{q}$'' description of the effective field theory. The analysis includes $η'$(958) from the beginning, and is largely concerned with structural questions. While the final results are mostly known, the method gives insight into the

P. Minkowski

Neutrino flavors, light and heavy, are discussed in their interdependence within the minimal unifying gauge group of SO10. The general situation which excludes the existence of an {\it exact} symmetry from which {\it exactly} vanishing light neutrino masses would follow is discussed. {\it Subtle} and {\it simple} consequences for 'low-low' oscillatio

Horace Stoica, S. -H. Henry Tye, Ira Wasserman

Giant resonances of gravity Kaluza-Klein modes (with tensor couplings) in high energy collisions are expected in the Randall-Sundrum orbifold model that incorporates a plausible solution to the hierarchy problem. When the model is extended to incorporate an exponentially small 4-D cosmological constant, the KK spectrum becomes continuous, even in the compact

F. Benatti, R. Floreanini

Quantum dynamical semigroups provide a general framework for studying the evolution of open systems. Neutrino propagation both in vacuum and in matter can be analyzed using these techniques: they allow a consistent treatment of non-standard, dissipative effects that can alter the pattern of neutrino oscillations. In particular, initially massless neutrinos c

Jean Pestieau

In the electroweak standard model we observe two remarkable empirical mass relations, m_W + m_B = v/2 and m_W - m_B = e v/2 where m^2_Z = m^2_W + m^2_B, e is the positron electric charge and v, the strength of the Higgs condensate.

M. Grazzini

I briefly review the progress in perturbative QCD calculations in LEP era and discuss the prospects for the extension of their accuracy to higher orders.

J. J. Gomez-Cadenas

The prospects of measuring CP violation in the leptonic sector using the intense neutrino beams arising from muon decay in the straight sections of a muon accumulator ring (the so-called neutrino factory) are discussed.

J. J. Gomez-Cadenas, A. Blondel, J. Burguet-Castell, D. Casper

The physics potential of high intensity conventional beams is explored. We consider a low energy super beam which could be produced by a proposed new accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowle

P. Bialas, J. Wosiek

Lattice discretization of the supersymmetric Yang-Mills quantum mechanics is reviewed and results of the Monte Carlo simulations of the simplified model are presented. The D=4, N=2, quenched system, studied at finite temperature, reveals existence of the two distinct regions which may correspond to a black hole and the elementary 0-branes phases of the M-the

PACS Collaboration, T. Yamazaki, S. Aoki, R. Burkhalter

We apply the maximum entropy method to extract the spectral functions for pseudoscalar and vector mesons from hadron correlators previously calculated at four different lattice spacings in quenched QCD with the Wilson quark action. We determine masses and decay constants for the ground and excited states of the pseudoscalar and vector channels from position

Martin Bojowald

The continuum and semiclassical limits of isotropic, spatially flat loop quantum cosmology are discussed, with an emphasis on the role played by the Barbero-Immirzi parameter γin controlling space-time discreteness. In this way, standard quantum cosmology is shown to be the simultaneous limit γ\to 0, j \to \infty of loop quantum cosmology. Here, j is a label

Takao Fukui, Sanjeev S. Seahra, Paul S. Wesson

An exact class of solutions of the 5D vacuum Einstein field equations (EFEs) is obtained. The metric coefficients are found to be non-separable functions of time and the extra coordinate $l$ and the induced metric on $l$ = constant hypersurfaces has the form of a Friedmann-Robertson-Walker cosmology. The 5D manifold and 3D and 4D submanifolds are in general

L. H. Ford, Chun-Hsien Wu

The quantum fluctuation of the stress tensor of a quantum field are discussed, as are the resulting spacetime metric fluctuations. Passive quantum gravity is an approximation in which gravity is not directly quantized, but fluctuations of the spacetime geometry are driven by stress tensor fluctuations. We discuss a decomposition of the stress tensor correlat

Ronald I. Greenberg, Lee Guan

This paper precisely analyzes the wire density and required area in standard layout styles for the hypercube. The most natural, regular layout of a hypercube of N^2 nodes in the plane, in a N x N grid arrangement, uses floor(2N/3)+1 horizontal wiring tracks for each row of nodes. (The number of tracks per row can be reduced by 1 with a less regular design.)

H. Uys, H. G. Miller, F. C. Khanna

Introducing the generalized, non-extensive statistics proposed by Tsallis[1988], into the standard s-wave pairing BCS theory of superconductivity in 2D yields a reasonable description of many of the main properties of high temperature superconductors, provided some allowance is made for non-phonon mediated interactions.

Nir Gov

Recent experiments show the thermal growth of dislocation lines in unlta-pure bcc $^{3}$He. The activation energy for the growth of the dislocation lines is found to agree with the activation energy of mass diffusion. We propose that these dislocations are topological defects in the phase of the complex order-parameter which describes the dynamic zero-point

D. J. Singh, I. I. Mazin

The electronic structure, stability, electron phonon coupling and superconductivity of the non-oxide perovskite MgCNi$_3$ are studied using density functional calculations. The band structure is dominated by a Ni $d$ derived density of states peak just below the Fermi energy, which leads to a moderate Stoner enhancement, placing MgCNi$_3$ in the range where

Georg Goeppert, Hermann Grabert

Claims by Kroha and Zawadowski in cond-mat/0105026 on inadequate approximations and an incorrect statement in cond-mat/0102150 are shown to be based on oversimplified estimates and a false quotation.

Jeng-Da Chai, Sergey V. Barabash, D. Stroud

We describe a simple model for calculating the zero-temperature superfluid density of Zn-doped YBa_2Cu_3O_{7-δ} as a function of the fraction x of in-plane Cu atoms which are replaced by Zn. The basis of the calculation is a ``Swiss cheese'' picture of a single CuO_2 layer, in which a substitutional Zn impurity creates a normal region of area $πξ_{ab

Iksoo Chang, Dietrich Stauffer

The percolation model of stock market speculation allows an asymmetry (in the return distribution) leading to fast downward crashes and slow upward recovery. We see more small upturns and more intermediate downturns.

Sanwu Wang, Massimiliano Di Ventra, S. G. Kim, Sokrates T. Pantelides

Oxidation of SiC produces SiO2 while CO is released. A `reoxidation' step at lower temperatures is, however, necessary to produce high-quality SiO2. This step is believed to cleanse the oxide of residual C without further oxidation of the SiC substrate. We report first-principles calculations that describe the nucleation and growth of O-deficient C clust

J. Lopez, P. N. Lisboa-Filho, O. F. de Lima, F. M. Araujo-Moreira

The magnetization at low temperatures for Nd0.5Sr0.5MnO3 and Nd0.5Ca0.5MnO3 samples showed a rapid increase with decreasing temperatures, contrary to a La0.5Ca0.5MnO3 sample. Specific heat measurement at low temperatures showed a Schottky-like anomaly for the first two samples. However, there is not a straight forward correlation between the intrinsic magnet

W. Yan, F. Claro, Z. Y. Zeng, J. Q. Liang

Within the one-dimensional tight-binding minibands and on-site Coloumbic interaction approximation, the absorption spectrum and coherent wavepacket time evolution in an optically excited semiconductor superlattice driven by dc-ac electric fields are investigated using the semiconductor Bloch equations. The dominating roles of the ratios of dc-Stark to extern

A. A. Aligia, P. Petrone, J. O. Sofo, B. Alascio

We construct an effective Hamiltonian for the motion of electrons among the transition metal ions of ordered double perovskites like Sr2FeMoO6. in which strong intra-atomic Coulomb repulsion U is present in only one of the inequivalent transition metal sites. Using a slave-boson formalism, we construct a phase diagram which describes a charge transfer transi

F. Kh. Abdullaev, B. B. Baizakov, V. V. Konotop

The dynamics of a 2D Bose-Einstein condensate in optical trap is studied taking into consideration fluctuations of the far-off-resonance laser field intensity. The problem is described in the frame of the mean field Gross-Pitaevskii equation with randomly varying trap potential. An analytic approach based on the moments method has been employed to describe t

M. R. Norman, M. Eschrig, A. Kaminski, J. C. Campuzano

We demonstrate that the E vs. k dispersion in the superconducting state extracted from momentum distribution curves differs qualitatively from the traditional dispersion extracted from energy distribution curves. This occurs because of a combination of many-body effects and the presence of an energy gap, along with the associated coherence factors. Analysis

G. M. Schott, W. Faschinger, L. W. Molenkamp

We perform high resolution X-ray diffraction on GaMnAs mixed crystals as well as on GaMnAs/GaAs and GaAs/MnAs superlattices for samples grown by low temperature molecular beam epitaxy under different growth conditions. Although all samples are of high crystalline quality and show narrow rocking curve widths and pronounced finite thickness fringes, the lattic

V. Lorman, R. Podgornik, B. Žekš

We investigate the orientational order of transverse polarization vectors of long, stiff polymer molecules and their coupling to bond orientational and positional order in high density mesophases. Homogeneous ordering of transverse polarization vector promotes distortions in the hexatic phase, whereas inhomogeneous ordering precipitates crystalization of the

E. Cappelluti, C. Grimaldi, L. Pietronero, S. Straessler

We show the intrinsic inconsistency of the conventional phonon mediated theory of superconductivity in relation to the observed properties of Rb$_3$C$_{60}$. The recent, highly accurate measurement of the carbon isotope coefficient $α_{\rm C}=0.21$, together with the high value of $T_c$ (30 K) and the very small Fermi energy $E_{\rm F}$ (0.25 eV), unavoidabl

Keshav N. Shrivastava

The High Landau level filling fractions 5/2, 7/3 and 8/3 are interpreted by using the angular momentum model. It is found that for the odd number of flux quanta, the quasiparticles called the ``composite fermions'' are fermions but for even number-, the quasiparticles are a mixture of bosons and fermions. Therefore, the theory of ``composite fermions

M. Niemetz, W. Schoepe

We investigate the statistical properties of single phase slip events observed in vortex nucleation experiments in He-4 by the groups in Berkeley and Paris. From the cumulative distribution function of the events we calculate the slip rate as a function of flow velocity. The critical velocity is defined as the mean velocity and its statistical width as the s

Erik Koch

We investigate the static charge response for the Hubbard model. Using the Slave-Boson method in the saddle-point approximation we calculate the charge susceptibility. We find that RPA works quite well close to half-filling, breaking, of course, down close to the Mott transition. Away from half filling RPA is much less reliable: Already for very small values

E. Nishibori, M. Takata, M. Sakata, H. Tanaka

The accurate charge density of MgB2 was observed at room temperature(R.T.) and 15K by the MEM(Maximum Entropy Method)/Rietveld analysis using synchrotron radiation powder data. The obtained charge density clearly revealed the covalent bonding feature of boron forming the 2D honeycomb network in the basal plane, on the other hand, Mg is found to be in divalen

Maia Angelova, A. Frank

An algebraic model based on Lie-algebraic techniques is applied to the analysis of thermodynamic vibrational properties of diatomic molecules. The local anharmonic effects are described by a Morse-like potential and corresponding anharmonic bosons associated with the U(2) algebra. A vibrational high temperature partition function and the related thermodynami

Jean-Noel Aqua, Francoise Cornu

In the framework of the grand-canonical ensemble of statistical mechanics, we give an exact diagrammatic representation of the density profiles in a classical multicomponent plasma near a dielectric wall. By a reorganization of Mayer diagrams for the fugacity expansions of the densities, we exhibit how the long-range of both the self-energy and pair interact

F. Dahlem, F. Evers, A. D. Mirlin, D. G. Polyakov

We investigate the quantum effects, in particular the Landau-level quantization, in the scattering of a particle the nonadiabatic classical dynamics of which is governed by an adiabatic invariant. As a relevant example, we study the scattering of a drifting particle on a magnetic barrier in the quantum limit where the cyclotron energy is much larger than a b

Pasquale Calabrese, Pietro Parruccini

We study the critical behavior of frustrated spin models with noncollinear order in two dimensions, including antiferromagnets on a triangular lattice and fully frustrated antiferromagnets. For this purpose we consider the corresponding $O(N) \times O(2)$ Landau-Ginzburg-Wilson (LGW) Hamiltonian and compute the field-theoretic expansion to four loops and det

Jean-Noel Aqua, Francoise Cornu

The equilibrium density profiles in a classical multicomponent plasma near a hard wall made with a dielectric material characterized by a relative dielectric constant $\ew$ are studied from the first Born-Green-Yvon equation combined with Poisson equation in a regime where Coulomb coupling is weak inside the fluid. In order to prevent the collapse between ch

L. Borda, G. Zarand

We study how the formation of the Kondo compensation cloud influences the dynamical properties of a magnetic impurity that tunnels between two positions in a metal. The Kondo effect dynamically generates a strong tunneling impurity-conduction electron coupling, changes the temperature dependence of the tunneling rate, and may ultimately result in the destruc

R. Roth, R. Evans, A. A. Louis

We show that the formal procedure of integrating out the degrees of freedom of the small spheres in a binary hard-sphere mixture works equally well for non-additive as it does for additive mixtures. For highly asymmetric mixtures (small size ratios) the resulting effective Hamiltonian of the one-component fluid of big spheres, which consists of an infinite n

P. Kalugin

A new method of the phase determination in X-ray crystallography is proposed. The method is based on the so-called "minimum charge" principle, recently suggested by Elser. The electron density function $ρ$ is sought in the form $ρ({\bf x})=|ψ({\bf x})|^2$, where $ψ$ is an $n{-component}$ real function. The norm $\int|ψ({\bf x})|^2 d{\bf x}$ is minimi

M. Praehofer, H. Spohn

The time-integrated current of the TASEP has non-Gaussian fluctuations of order $t^{1/3}$. The recently discovered connection to random matrices and the Painlevé II Riemann-Hilbert problem provides a technique through which we obtain the probability distribution of the current fluctuations, in particular their dependence on initial conditions, and the statio

K. L. Luhman

I present a comprehensive study of the MBM12 young association (MBM12A). By combining infrared (IR) photometry from the Two-Micron All-Sky Survey (2MASS) survey with new optical imaging and spectroscopy, I have performed a census of the MBM12A membership that is complete to 0.03 Msun (H~15) for a 1.75deg X 1.4deg field encompassing the MBM12 cloud. I find fi

Ronald A. Remillard, Gregory J. Sobczak, Michael P. Muno, Jeffrey E. McClintock

For all 209 RXTE observations of the X-ray nova XTE J1550-564 during its major outburst of 1998-1999, we have analyzed the X-ray power spectra, phase lags, and coherence functions. The phase lags and coherence measures are used to distinguish three types of low-frequency QPOs (one more than those reported by Wijnands, Homan, & van der Klis 1999). For the mos

Ivan Hubeny, Omer Blaes, Julian H. Krolik, E. Agol

We extend our models of the vertical structure and emergent radiation field of accretion disks around supermassive black holes described in previous papers of this series. Our models now include both a self-consistent treatment of Compton scattering and the effects of continuum opacities of the most important metal species (C, N, O, Ne, Mg, Si, S, Ar, Ca, Fe

Benjamin F. Williams, Paul W. Hodge

We present a method for finding clusters of young stars in M31 using broadband WFPC2 data from the HST data archive. Applying our identification method to 13 WFPC2 fields, covering an area of ~60 arcmin^2, has revealed 79 new candidate young star clusters in these portions of the M31 disk. Most of these clusters are small (~<5 pc) young (~10-200 Myr) star gr

Chris Done

Hard X-ray emission is ubiquitous in accreting black holes, both in Galactic binary systems and in Active Galactic Nuclei. I review the different spectra which can be seen from these systems, and possible ways of producing this emission. X-ray reflection should give an observational test of these scenarios, but we need better models before this can give an u

Lev Titarchuk, Vladimir Osherovich

We present a theoretical analysis of Rossi X-ray Timing Explorer data of Z source GX 340+0 obtained by Jonker et al. In the frameworks of the recently formulated the transition layer model the delta-angle is an angle between the neutron star (NS) magnetospheric axis and the disk (presumably NS rotational) axis.We determine the angle delta=6^o.3+/- 0.^o 3 whi

Daniel Huber, Daniel Pfenniger

Following Toomre & Kalnajs (1991), local models of slightly dissipative self-gravitating disks show how inhomogeneous structures can be maintained over several galaxy rotations. Their basic physical ingredients are self-gravity, dissipation and differential rotation. In order to explore the structures resulting from these processes on the kpc scale, local si

J. R. Thorstensen, C. J. Taylor

We present spectroscopy and orbital periods Porb of four relatively little-studied cataclysmic variable stars. The stars and their periods are: AF Cam, Porb = 0.324(1) d (the daily cycle count is slightly ambiguous); V2069 Cyg (= RX J2123.7+4217), 0.311683(2) d; PG 0935+075, 0.1868(3) d; and KUV 03580+0614, 0.1495(6) d. V2069 Cyg and KUV 03580+0614 both show

F. Durret, S. Dos Santos, R. Lieu

We have performed the wavelet analysis and image reconstructions for six clusters of galaxies observed both at extreme ultraviolet and X-ray energies. The comparison of the profiles of the EUV and X-ray reconstructed images shows that they differ at a very large confidence level in five of the six clusters, and are similar only for the Coma cluster, which is

Yveline Lebreton, João Fernandes, Thibault Lejeune

We compare the accurate empirical mass-luminosity (M-L) relation based on five Hyades binary systems to predictions of stellar models calculated with various input parameters (helium, metallicity, age) or physics (mixing-length ratio, model atmosphere, equation of state, microscopic diffusion). Models based on a helium content Ysim0.28 inferred from the dydz

Florence Durret, Ricardo Demarco, Frederic Magnard, Daniel Gerbal

Self-gravitating systems such as elliptical galaxies appear to have a constant specific entropy and obey a scaling law relating their potential energy to their mass. These properties can be interpreted as due to the physical processes involved in the formation of these structures. Dark matter haloes obtained through numerical simulations have also been found

Pasquale Panuzzo, Alessandro Bressan, Gian Luigi Granato, Laura Silva

Star forming galaxies exhibit a variety of physical conditions, from quiescent normal spirals to the most powerful dusty starbursts. In order to study these complex systems, we need a suitable tool to analyze the information coming from observations at all wavelengths. We present a new spectro-photometric model which considers in a consistent way starlight a

J. S. Yadav, A. R. Rao

We present results of our analysis of a set of RXTE/PCA observations of X-ray flares/bursts with burst cycle ranging from 30 to 1300 s from the Galactic X-ray transient source GRS 1915+105 during last four years. These flares/bursts can be classified into four types: 1) regular bursts with short burst phase of about 20 s (R1), 2) regular bursts with short qu

Takahiko Matsubara, Alexander S. Szalay

We show how the cosmological constant can be estimated from redshift surveys at different redshifts, using maximum-likelihood techniques. The apparent redshift-space clustering on large scales (\simgt 20 \himpc) are affected in the radial direction by infall, and curvature influences the apparent correlations in the transverse direction. The relative strengt

Christopher J. Conselice, John S. Gallagher, Rosemary F. G. Wyse

Early-type dwarfs are the most common galaxy in the local universe, yet their origin and evolution remain a mystery. Various cosmological scenarios predict that dwarf-like galaxies in dense areas are the first to form and hence should be the oldest stellar systems in clusters. By using radial velocities of early-type dwarfs in the Virgo cluster we demonstrat

Peter M. Garnavich, Alceste Z. Bonanos, Kevin Krisciunas, Saurabh Jha

We present UBVRIJHK photometry and optical spectroscopy of the so-called &#39;peculiar&#39; Type Ia supernova 1999by in NGC 2841. The observations began one week before visual maximum light which is well-defined by daily observations. The light curves and spectra are similar to those of the prototypical subluminous event SN 1991bg. We find that maximum light

Igor F. Herbut

A general scenario that leads to Coulomb quantum criticality with the dynamical critical exponent z=1 is proposed. I point out that the long-range Coulomb interaction and quenched disorder have competing effects on z, and that the balance between the two may lead to charged quantum critical points at which z=1 exactly. This is illustrated with the calculatio

Andreas U. Schmidt

We present a method for the construction of a Krein space completion for spaces of test functions, equipped with an indefinite inner product induced by a kernel which is more singular than a distribution of finite order. This generalizes a regularization method for infrared singularities in quantum field theory, introduced by G. Morchio and F. Strocchi, to t

Wee Liang Gan, Victor Ginzburg

We give a direct proof of (a slight generalization of) the recent result of A. Premet related to generalized Gelfand-Graev representations and of an equivalence due to Skryabin.

A. Albrecht, C. P. Burgess, F. Ravndal, C. Skordis

We show how the presence of a very light scalar with a cubic self-interaction in six dimensions can stabilize the extra dimensions at radii which are naturally exponentially large, $r \sim \ell \exp [(4π)^3/g^2]$, where $\ell$ is a microscopic physics scale and $g$ is the (dimensionless) cubic coupling constant. The resulting radion mode of the metric become

Walter Rantner, Xiao-Gang Wen

The single particle spectral function for the normal state of underdoped high $T_c$ cuprates is studied within the slave particle framework. We find that the presence of a massless dynamical gauge field - a direct consequence of the quantum order - explains the broad, but not totally incoherent, line-shapes observed in experiments. The issue of the negative

Massimo Bianchi, Daniel Z. Freedman, Kostas Skenderis

We apply the formalism of holographic renormalization to domain wall solutions of 5-dimensional supergravity which are dual to deformed conformal field theories in 4 dimensions. We carefully compute one- and two-point functions of the energy-momentum tensor and the scalar operator mixing with it in two specific holographic flows, resolving previous difficult

Kimmo Kainulainen, Tomislav Prokopec, Michael G. Schmidt, Steffen Weinstock

We perform a systematic gradient expansion on kinetic equations and derive the CP-violating semiclassical force for fermions propagating in presence of a CP-violating wall at a first order electroweak phase transition. The force appears at order h-bar in the flow term of the kinetic equation and agrees with the semiclassical force used for baryogenesis compu

Luigi Amico, Antonio Di Lorenzo, Andreas Osterloh

We study integrable models for electrons in metals when the single particle spectrum is discrete. The electron-electron interactions are BCS-like pairing, Coulomb repulsion, and spin exchange coupling. These couplings are, in general, nonuniform in the sense that they depend on the levels occupied by the interacting electrons. By using the realization of spi

V. Berezinsky, M. C. Gonzalez-Garcia, C. Peña-Garay

We discuss the status of the Gribov-Pontecorvo (GP) solution to the solar neutrino problem. This solution naturally appears in bimaximal neutrino mixing and reduces the solar and atmospheric neutrino problems to vacuum oscillations of three active neutrinos. The GP solution predicts an energy-independent suppression of the solar neutrino flux. It is disfavou

G. A. Alekseev

A new development of the ``monodromy transform&#39;&#39; method for analysis of hyperbolic as well as elliptic integrable reductions of Einstein equations is presented. Compatibility conditions for some alternative representations of the fundamental solutions of associated linear systems with spectral parameter in terms of a pair of dressing (``scattering&#3

P. Haensel

Apparent (radiation) radius of neutron star,R_\infty, depends on the star gravitational mass in quite a different way than the standard coordinate radius in the Schwarzschild metric, R. We show that, for a broad set of equations of state of dense matter, R_\infty(M_max) for the configurations with maximum allowable masses is very close to the absolute lower

G. Losurdo, G. Calamai, E. Cuoco, L. Fabbroni

In order to achieve full detection sensitivity at low frequencies, the mirrors of interferometric gravitational wave detectors must be isolated from seismic noise. The VIRGO vibration isolator, called &#39;superattenuator&#39;, is fully effective at frequencies above 4 Hz. Nevertheless, the residual motion of the mirror at the mechanical resonant frequencies

V. Aldaya, J. L. Jaramillo, J. Guerrero

The dynamics of a particle moving in background electromagnetic and gravitational fields is revisited from a Lie group cohomological perspective. Physical constants characterising the particle appear as central extension parameters of a group which is obtained from a centrally extended kinematical group (Poincare or Galilei) by making local some subgroup. Th

Andrea Refolli, Alberto Santambrogio, Niccolo&#39; Terzi, Daniela Zanon

We consider the N=4 supersymmetric Yang-Mills theory in four dimensions. We compute the one-loop contributions to the effective action with five external vector fields and compare them with corresponding results in open superstring theory. Our calculation determines the structure of the F^5 terms that appear in the nonabelian generalization of the Born Infel

J. Davidsen, M. Paczuski

We show that large, slowly driven systems can evolve to a self-organized critical state where long range temporal correlations between bursts or avalanches produce low frequency $1/f^α$ noise. The avalanches can occur instantaneously in the external time scale of the slow drive, and their event statistics are described by power law distributions. A specific

Sadhan K. Adhikari

The dynamics of stability and collapse of a trapped atomic Bose-Einstein condensate (BEC) coupled to a molecular one is studied using the time-dependent Gross-Pitaevskii (GP) equation including a nonlinear interaction term which can transform two atoms into a molecule and vice versa. We find interesting oscillation of the number of atoms and molecules for a

Wolfgang Dobler, Anvar Shukurov, Axel Brandenburg

The self-excitation of magnetic field by a spiral Couette flow between two coaxial cylinders is considered. We solve numerically the fully nonlinear, three-dimensional MHD equations for magnetic Prandtl numbers Pm (ratio of kinematic viscosity to magnetic diffusivity) between 0.14 and 10 and kinematic and magnetic Reynolds numbers up to about 2000. In the in

L. Laperashvili, H. B. Nielsen, D. A. Ryzhikh

Using a 2-loop approximation for $β$-functions, we have considered the corresponding renormalization group improved effective potential in the Dual Abelian Higgs Model (DAHM) of scalar monopoles and calculated the phase transition (critical) couplings in U(1) and SU(N) regularized gauge theories. In contrast to our previous result $α_{crit} \approx 0.17$, ob