February 2002 arXiv papers — page 22

S. Schmeja, S. Kimeswenger

We present near-infrared photometry of a large sample of planetary nebulae (PNe) and show that the IJK colours are a good tool to distinguish different classes of PNe, like nebulae around symbiotic Miras or IR-[WC] PNe from genuine PNe.

Olga K. Silchenko

We describe the history and results of our study of early-type disk galaxies with the Multi-Pupil Spectrograph of the 6m telescope (MPFS). With the new data we confirm the discovery of chemically distinct nuclei reported in 1992; now such nuclei are found in two dozens galaxies. The structure of chemically distinct features formed probably in secondary nucle

J. -M. Miralles, T. Erben, H. Haemmerle, P. Schneider

We report the serendipituous discovery of a conspicuous alignment of galaxies in a field obtained through the STIS Parallel Shear Survey. This project collects randomly distributed 50'' x 50'' fields to investigate the cosmic shear effect on this scale. Analyzing the parallel observations having the Seyfert galaxy NGC625 as primary target, we

M. Goto, N. Kobayashi, H. Terada, A. T. Tokunaga

We present ground-based high-resolution (~0".3) imaging of AFGL 2688 at L' (3.8 um) and M'(4.7um). A wealth of structure in the central region is revealed due to less extinction in the thermal infrared. A clear border in the southern lobe at L' corresponds to the edge of the heavily obscured region in visible, indicating there is a dense mate

B. Kalman

Comparison of photographic observations and vector-magnetograph measurements demonstrate, that the outer boundary of the sunspot penumbra --even in complex sunspot groups-- closely follows the 0.075T isogauss line of the total value of the magnetic field, corresponding approximately to the equipartition value in the photosphere. Radio observations also show

M. Goto, N. Kobayashi, H. Terada, W. Gaessler

We present near-infrared spectroscopy of low-mass companions in a nearby triple system HD 130948 (Gliese 564, HR 5534). Adaptive optics on the Subaru Telescope allowed spectroscopy of the individual components of the 0".13 binary system. Based on a direct comparison with a series of template spectra, we determined the spectral types of HD 130948B and C t

Ulisse Munari, Rajka Jurdana-Sepic

The Asiago photographic archive has been searched for plates containing the symbiotic stars Hen 2-468, QW Sge, LT Del, V407 Cyg, K 3-9, V335 Vul, FG Ser and Draco C-1. A total of 635 plates imaging the program stars have been found and the brightness estimated using the Henden & Munari (2000) UBVRI photometric sequences. These historical data have allowed fo

M. A. Garrett

The correlation between the far-infrared (FIR) and radio emission is well established for nearby star forming galaxies. Many applications, in particular the radio-to-submm spectral index redshift indicator, tacitly assume that the relation holds well beyond our local neighbourhood, to systems located at cosmological distances. In order to test this assumptio

Swapan K Saha

The present `state of the art' and the path to future progress in high spatial resolution imaging interferometry is reviewed. The review begins with a treatment of the fundamentals of stellar optical interferometry, the origin, properties, optical effects of turbulence in the Earth's atmosphere, the passive methods that are applied on a single telesc

T. Kajino, M. Orito, G. J. Mathews, R. N. Boyd

We study the primordial nucleosynthesis and cosmic age in the presence of a net lepton asymmetry as well as baryon asymmetry. We explore a previously unnoted region of the parameter space in which very large baryon densities $0.1 \le Ω_b \le 1$ can be accommodated within the light-element constraints from primordial nucleosynthesis. This parameter space cons

Motoyuki Saijo, Thomas W. Baumgarte, Stuart L. Shapiro, Masaru Shibata

We study the gravitational collapse of a rotating supermassive star (SMS) by means of a (3+1) hydrodynamical simulation in a post-Newtonian (PN) approxi- mation of general relativity. This problem is particularly challenging because of the vast dynamical range in space which must be covered in the course of col- lapse. We evolve a uniformly rotating SMS from

V. M. Kaspi, D. J. Helfand

The prescient remark by Baade and Zwicky that supernovae beget neutron stars did little to prepare us for the remarkable variety of observational manifestations such objects display. Indeed, during the first thirty years of the empirical study of neutron stars, only a handful were found to be associated with the remnants of exploded stars. But recent X-ray a

K. Adcox, PHENIX Collaboration

Transverse momentum spectra of electrons from Au+Au collisions at sqrt(s_NN) = 130 GeV have been measured by the PHENIX experiment at RHIC. The spectra show an excess above the background from photon conversions and light hadron decays. The electron signal is consistent with that expected from semi-leptonic decays of charm. The yield of the electron signal d

R. Pillarisetty, Hwayong Noh, D. C. Tsui, E. P. De Poortere

We report drag measurements on dilute double layer two-dimensional hole systems in the regime of r_s=19~39. We observed a strong enhancement of the drag over the simple Boltzmann calculations of Coulomb interaction, and deviations from the T^2 dependence which cannot be explained by phonon-mediated, plasmon-enhanced, or disorder-related processes. We suggest

J. W. Moffat

In the bimetric scalar-tensor gravitational theory there are two frames associated with the two metrics {\hat g}_{μν} and g_{μν}, which are linked by the gradients of a scalar field ϕ. The choice of a comoving frame for the metric {\hat g}_{μν} or g_{μν} has fundamental consequences for local observers in either metric spacetimes, while maintaining diffeomor

Debabrata Panja, Ramses van Zon

We demonstrate why for a sheared gas of hard spheres, described by the SLLOD equations with an iso-kinetic Gaussian thermostat in between collisions, deviations of the conjugate pairing rule for the Lyapunov spectrum are to be expected, employing a previous result that for a large number of particles $N$, the iso-kinetic Gaussian thermostat is equivalent to

Debabrata Panja, Ramses van Zon

We consider a dilute gas of hard spheres under shear. We use one of the predominant models to study this system, namely the SLLOD equations of motion, with an iso-kinetic Gaussian thermostat in between collisions, to get a stationary total peculiar kinetic energy. Based on the previously obtained result that in the non-equilibrium steady state and in case th

Jonathan Walgate, Lucien Hardy

Entanglement is an useful resource because some global operations cannot be locally implemented using classical communication. We prove a number of results about what is and is not locally possible. We focus on orthogonal states, which can always be globally distinguished. We establish the necessary and sufficient conditions for a general set of 2x2 quantum

Donald C. Ellison, Glen P. Double

Monte Carlo techniques are used to model nonlinear particle acceleration in parallel collisionless shocks of various speeds, including mildly relativistic ones. When the acceleration is efficient, the backreaction of accelerated particles modifies the shock structure and causes the compression ratio, r, to increase above test-particle values. Modified shocks

Vahid Rezania

We study the dynamics of r-modes in the ocean of a magnetic neutron star. We modeled the star's ocean with a spherical rotating thin shell and assumed that the magnetic field symmetry axis is not aligned to the shell's spin axis. In the magnetohydrodynamic approximation, we calculate the frequency of $\ell=m$ r-modes in the shell of an incompressible

Samuel M. Leach, Andrew R. Liddle, Jerome Martin, Dominik J. Schwarz

We consider approaches to cosmological parameter estimation in the inflationary cosmology, focussing on the required accuracy of the initial power spectra. Parametrizing the spectra, for example by power-laws, is well suited to testing the inflationary paradigm but will only correctly estimate cosmological parameters if the parametrization is sufficiently ac

E. J. Copeland, S. Pascoli, A. Rajantie

We study the instability of a scalar field at the end of hybrid inflation, using both analytical techniques and numerical simulations. We improve previous studies by taking the inflaton field fully into account, and show that the range of unstable modes depends sensitively on the velocity of the inflaton field, and thereby on the Hubble rate, at the end of i

N. Borghini, P. M. Dinh, J. -Y. Ollitrault, A. M. Poskanzer

We present a general method for taking into account correlations due to momentum conservation in the analysis of anisotropic flow, either by using the two-particle correlation method or the standard flow vector method. In the latter, the correlation between the particle and the flow vector is either corrected through a redefinition (shift) of the flow vector

J. M. Roman, G. Sierra, J. Dukelsky

We have studied the numerical solutions of Richardson equations of the BCS model in the limit of large number of energy levels at half-filling, and compare them with the analytic results derived by Gaudin and Richardson, which in turn leads to the standard BCS solution. We focus on the location and density of the roots, the eigenvalues of the conserved quant

Ludovic Berthier, Jean-Philippe Bouchaud

We present a comprehensive study of non-equilibrium phenomena in the low temperature phase of the Edwards-Anderson Gaussian spin glass in 3 and 4 spatial dimensions. Many effects can be understood in terms of a time dependent coherence length, $\ell_T$, such that length scales smaller that $\ell_T$ are equilibrated, whereas larger length scales are essential

J. Conrad, O. Botner, A. Hallgren, Carlos P. de los Heros

One way to incorporate systematic uncertainties into the calculation of confidence intervals is by integrating over probability density functions parametrizing the uncertainties. In this note we present a development of this method which takes into account uncertainties in the prediction of background processes, uncertainties in the signal detection efficien

A. Osterloh, L. Amico, G. Falci, R. Fazio

In this Letter we discuss the entanglement near a quantum phase transition by analyzing the properties of the concurrence for a class of exactly solvable models in one dimension. We find that entanglement can be classified in the framework of scaling theory. Further, we reveal a profound difference between classical correlations and the non-local quantum cor

Giuseppe Nardulli

We describe the effective lagrangian approach to the color superconductivity. The effective description that arises if one considers only the leading terms in the expansion for very high densities is particularly simple. It is based on a lagrangian whose effective fermion fields are velocity-dependent; moreover strong interactions do not change quark velocit

Shahrokh Parvizi

By using the so-called Information Metric on the moduli space of an anti-selfdual (ASD) Instanton in a Self-Dual (SD) Non-Commutative background, we investigate the geometry of moduli space. The metric is evaluated perturbatively in non-commutativity parameter and we show that by putting a cut-off in the location of instanton in the definition of Information

Satya N. Majumdar, Alain Comtet

We consider a particle moving in a one dimensional potential which has a symmetric deterministic part and a quenched random part. We study analytically the probability distributions of the local time (spent by the particle around its mean value) and the occupation time (spent above its mean value) within an observation time window of size t. The random part

B. Larsson, R. Liseau, A. B. Men'shchikov

We present spectrophotometric ISO imaging with the LWS and the CAM-CVF of the Serpens molecular cloud core. The LWS map is centred on the far infrared and submillimetre source SMM1 and its size is 8' x 8'. The fine structure line emission in [OI] and [CII] is extended and can be successfully modelled to originate in a PDR with G_0 = 15 and n(H2) abou

Zhi-zhong Xing

We present a concise formula to relate the effective mass term of the neutrinoless double beta decay to a single neutrino mass, two Majorana CP-violating phases and four observables of neutrino oscillations for a generic neutrino mass spectrum. If the alleged evidence for the neutrinoless double beta decay is taken into account, one may obtain a rough but mo

Jun-Chen Su

The interaction kernel in the Bethe-Salpeter equation for quark-antiquark bound states is derived from the Bethe-Salpeter equations satisfied by the quark-antiquark four-point Green's function. The latter equations are established based on the equations of motion obeyed by the quark and antiquark propagators, the four-point Green's function and some

S. Marchesini, C. S. Fadley, F. J. Garcia de Abajo

X-ray fluorescence holography (XFH) is a method for obtaining diffraction-limited images of the local atomic structure around a given type of emitter. The reconstructed wave-field represents a distorted image of the scatterer electron density distribution; {\it i.e.} it is a convolution of the charge density distribution with a point spread function characte

L. K. Thomsen, S. Mancini, H. M. Wiseman

We propose a quantum feedback scheme for producing deterministically reproducible spin squeezing. The results of a continuous nondemolition atom number measurement are fed back to control the quantum state of the sample. For large samples and strong cavity coupling, the squeezing parameter minimum scales inversely with atom number, approaching the Heisenberg

L. K. Thomsen, H. M. Wiseman

We present a quantum-mechanical treatment of the coherence properties of a single-mode atom laser. Specifically, we focus on the quantum phase noise of the atomic field as expressed by the first-order coherence function, for which we derive analytical expressions in various regimes. The decay of this function is characterized by the coherence time, or its re

Hou Hong-Sheng, Ma Wen-Gan, Wan Lang-Hui, Zhang Ren-You

The electroweak corrections at the order of $O(α_{ew}m_{t(b)}^2/m_W^2)$ to the partial widths of the $\tilde{t}_2 \to \tilde{g} + t$ and $\tilde{g} \to \tilde{t}_1 + \bar{t} $ decays (depending on the masses of the particles involved) are investigated within the Supersymmetric Standard Model. The relative corrections can reach the value of 10% in some parame

Lov K. Grover

The scheduling problem consists of finding a common 1 in two remotely located N bit strings. Denote the number of 1s in the string with the fewer 1s by epsilon*N. Classically, it needs at least O(epsilon*N) bits of communication to find the common 1 (ignoring logarithmic factors). The best known quantum algorithm would require O(sqrt(N)) qubits of communicat

G. Kaniadakis, A. M. Scarfone

We consider systems, which conserve the particle number and are described by Schrödinger equations containing complex nonlinearities. In the case of canonical systems, we study their main symmetries and conservation laws. We introduce a Cole-Hopf like transformation both for canonical and noncanonical systems, which changes the evolution equation into anothe

K. M. Fonseca Romero, S. G. Mokarzel, M. C. Nemes

We consider N identical oscillators coupled to a single environment and show that the conditions for the existence of decoherence free subspaces are degeneracy of the oscillator frequencies and separability of the coupling with the environment. A formal exact equation for the evolution in the case of two oscillators is found and the decoherence free subspace

Yuri Ozhigov, Leonid Fedichkin

It is proved that a quantum computer with fixed and permanent interaction of diagonal type between qubits proposed in the work quant-ph/0201132 is universal. Such computer is controlled only by one-qubit quick transformations, and this makes it feasible.

Carlos Castro, Jorge Mahecha, Boris Rodriguez

A new nonlinear Schroedinger equation is obtained explicitly from the fractal Brownian motion of a massive particle with a complex-valued diffusion constant. Real-valued energy (momentum) plane wave and soliton solutions are found in the free particle case. The hydro-dynamical model analog yields another (new) nonlinear QM wave equation with physically meani

Stefan Schippers, Stefan Kieslich, Alfred Mueller, Gerald Gwinner

Absolute total electron-ion recombination rate coefficients of argonlike Sc3+(3s2 3p6) ions have been measured for relative energies between electrons and ions ranging from 0 to 45 eV. This energy range comprises all dielectronic recombination resonances attached to 3p -> 3d and 3p -> 4s excitations. A broad resonance with an experimental width of 0.89 +- 0.

Y. Bibel, B. Klappauf, J. C. Bernard, D. Delande

We study light coherent transport in the weak localization regime using magneto-optically cooled strontium atoms. The coherent backscattering cone is measured in the four polarization channels using light resonant with a J=0 to J=1 transition of the Strontium atom. We find an enhancement factor close to 2 in the helicity preserving channel, in agreement with

Akihiro Ohtake, Shiro Tsukamoto, Markus Pristovsek, Nobuyuki Koguchi

Structure of the Ga-stabilized GaAs(001)-c(8x2) surface has been studied using rocking-curve analysis of reflection high-energy electron diffraction (RHEED). The c(8x2) structure emerges at temperatures higher than 600C, but is unstable with respect to the change to the (2x6)/(3x6) structure at lower temperatures. Our RHEED rocking-curve analysis at high tem

Rob de Ruyter van Steveninck, William Bialek

We measure the reliability of signals at three levels within the blowfly visual system, and present a theoretical framework for analyzing the experimental results, starting from the Poisson process. We find that blowfly photoreceptors, up to frequencies of 50-100 Hz and photon capture rates of up to about 3*10^5/s, operate well within an order of magnitude f

Shiro Tsukamoto, Markus Pristovsek, Bradford G. Orr, Akihiro Ohtake

As-rich GaAs (001) surfaces are successfully observed during As4-irradition by a system in which scanning tunneling microscopy (STM) and molecular beam epitaxy can be performed simultaneously. With a substrate temperature of 440 C and an As4 partial pressure of 2x10-6 torr, reflection high energy electron diffraction patterns and reflectance anisotropy spect

Fran De Aquino

It will be shown that the gravitational masses of the electrons of a superconducting material are strongly negative. Particularly, for an amount of mercury (Hg) at the transition temperature, Tc = 4.15 K, the negative gravitational masses of the electrons decrease the total gravitational mass of the Hg of approximately 0.1 percent. The weight reduction incre

Martin Rivas

A direct measurement of the relative orientation between the spin and magnetic moment of the electron seems to be never performed. The kinematical theory of elementary particles developed by the author and the analysis of the expectation value of Dirac's magnetic moment operator show that, contrary to the usual assumption, spin and magnetic moment of ele

J. R. Smith, G. A. Miller

A light front formalism for deep inelastic lepton scattering from finite nuclei is developed. In particular, the nucleon plus momentum distribution and a finite system analog of the Hugenholtz-van Hove theorem are presented. Using a relativistic mean field model, numerical results for the plus momentum distribution and ratio of bound to free nucleon structur

L. C. Chamon, B. V. Carlson, L. R. Gasques, D. Pereira

Extensive systematization of theoretical and experimental nuclear densities and of optical potential strengths exctracted from heavy-ion elastic scattering data analyses at low and intermediate energies are presented.The energy-dependence of the nuclear potential is accounted for within a model based on the nonlocal nature of the interaction.The systematics

J. Golak, R. Skibinski, W. Gloeckle, H. Kamada

A benchmark is set on the three-nucleon photodisintegration calculating the total cross section with modern realistic two- and three-nucleon forces (AV18, UrbIX) using both the Faddeev equations and the Lorentz Integral Transform method. This test shows that the precision of three-body calculations involving continuum states is considerably higher than exper

K. Nakayama, J. Speth, T. -S. H. Lee

Eta meson production in both proton-proton and proton-neutron collisions is investigated within a relativistic meson exchange model of hadronic interactions. It is found that the available cross section data can be described equally well by either the vector or pseudoscalar meson exchange mechanism for exciting the S_{11}(1535) resonance. It is shown that th

N. A. Orr

Selected topics on halo and molecular states in light, neutron-rich nuclei are discussed. In particular, work on $xα$:X$n$ structures is briefly reviewed. The use of proton radiative capture as a probe of clustering is also presented through the example provided by the $^6$He(p,$γ$) reaction.

B. Konopelchenko, L. Martinez Alonso, E. Medina

A $\bar{\partial}$-formalism for studying dispersionless integrable hierarchies is applied to the dKP hierarchy. Connections with the theory of quasiconformal mappings on the plane are described and some clases of explicit solutions of the dKP hierarchy are presented.

Bernard J. Geurts, Darryl D. Holm

The $α$-modeling strategy is followed to derive a new subgrid parameterization of the turbulent stress tensor in large-eddy simulation (LES). The LES-$α$ modeling yields an explicitly filtered subgrid parameterization which contains the filtered nonlinear gradient model as well as a model which represents `Leray-regularization'. The LES-$α$ model is comp

Takeshi Ikeda, Hiro-Fumi Yamada

A family of polynomial τ-functions for the NLS-Toda hierarchy is constructed. The hierarchy is associated with the homogeneous vertex operator representation of the affine algebra \g of type A_1^{(1)}. These τ-functions are given explicitly in terms of Schur functions that correspond to rectangular Young diagrams. It is shown that an arbitrary polynomial τ-f

Jean-Bernard Bru, Bruno Nachtergaele, Valentin Zagrebnov

We study the equilibrium Gibbs states for a Boson gas model, defined by Bru and Zagrebnov, which has two phase transitions of the Bose condensation type. The two phase transitions correspond to two distinct mechanisms by which these condensations can occur. The first (non-conventional) Bose condensation is mediated by a zero-mode interaction term in the Hami

A. S. Dzhumadil'daev

Filipov proved that Jacobian algebra is n-Lie. In our paper we consider algebras defined on associative commutative algebra U with derivation $\der$ by (k+1)-multiplication $V^{0,1,...,k}=\der^0\wedge\der^1\wedge...\wedge \der^k$ (Wronskian). We study whether they have (k+1)-Lie, k-left commutative and homotopical (k+1)-Lie structures.

Nicholas J. Kuhn

This paper begins by noting that, in a 1969 paper in the Transactions, M.C.McCord introduced a construction that can be interpreted as a model for the categorical tensor product of a based space and a topological abelian group. This can be adapted to Segal's very special Gamma--spaces, and then to a more modern situation: (K tensor R) where K is a based

A. S. Dzhumadil'daev

Let $V_n=<e_1,...,e_{n+1}>$ be a vector products n-Lie algebra with n-Lie commutator $[e_1,...,\hat{e_i},...,e_{n+1}]=(-1)^ie_i$ over the field of complex numbers. Any finite-dimensional n-Lie $V_n$-module is completely reducible. Any finite-dimensional irreducible n-Lie $V_n$-module is isomorphic to a n-Lie extension of $so_{n+1}$-module with highest weight

A. S. Dzhumadil&#39;daev

Constructions of n-Lie algebras by strong n-Lie-Poisson algebras are given. First cohomology groups of adjoint module of Jacobian algebras are calculated. Minimal identities of 3-Jacobian algebra are found.

Dimitri Tamarkin

Action of the graded Grothendieck-Teichmueller (GT) group on a resolution of the operad of Gerstenhaber algebras (GA) is defined. It is shown that the induced Lie algebra action is homotopically non-trivial (i.e. the induced map from the Lie algebra of the graded GT group to the deformation complex of the operad of GA is injective).

O. I. Mokhov

The nonlinear equations for the general nonsingular pairs of compatible nonlocal Poisson brackets of hydrodynamic type are derived and the integrability of these equations by the method of inverse scattering problem is proved. For these equations, the Lax pairs with a spectral parameter are presented. Moreover, we demonstrate the integrability of the equatio

Kazuo Akutagawa, Boris Botvinnik, Osamu Kobayashi, Harish Seshadri

For a compact manifold $M$ of $\dim M =n\geq 4$, we study two conformal invariants of a conformal class $C$ on $M$. These are the Yamabe constant $Y_C(M)$ and the $L^{\frac{n}{2}}$-norm $W_C(M)$ of the Weyl curvature. We prove that for any manifold $M$ there exists a conformal class $C$ such that the Yamabe constant $Y_C(M)$ is arbitrarily close to the Yamab

J. F. Vazquez-Poritz

For a brane world embedded in various ten or eleven-dimensional geometries, we calculate the corrections to the four-dimensional gravitational potential due to graviton modes propagating in the extra dimensions, including those rotating around compact directions. Due to additional &#34;warp&#34; factors, these rotation modes may have as significant an effect

Edmund J Copeland

We present a brief review of recent advances in string cosmology. Starting with the Dilaton-Moduli Cosmology (known also as the Pre Big Bang), we go on to include the effects of axion fields and address the thorny issue of the Graceful Exit in String Cosmology. This is followed by a review of density perturbations arising in string cosmology and we finish wi

E. T. Akhmedov, A. V. Smilga

We make two remarks: (i) Renormalization of the effective charge in a 4--dimensional (supersymmetric) gauge theory is determined by the same graphs and is rigidly connected to the renormalization of the metric on the moduli space of the classical vacua of the corresponding reduced quantum mechanical system. Supersymmetry provides constraints for possible mod

Ralph Blumenhagen, Boris Kors, Dieter Lust

Starting from the non-supersymmetric, tachyon-free orientifold of type 0 string theory, we construct four-dimensional brane world models with D6-branes intersecting at angles on internal tori. They support phenomenologically interesting gauge theories with chiral fermions. Despite the theory being non-supersymmetric the perturbative scalar potential induced

Steve Corley, Antal Jevicki, Sanjaye Ramgoolam

A class of correlation functions of half-BPS composite operators are computed exactly (at finite $N$) in the zero coupling limit of N=4 SYM theory. These have a simple dependence on the four-dimensional spacetime coordinates and are related to correlators in a one-dimensional Matrix Model with complex Matrices obtained by dimensional reduction of N=4 SYM on

J. Kalinowski

In supersymmetric models new sources of lepton flavour violation (LFV) may enhance the rates of charged lepton flavour violating processes, like mu to e gamma, and generate distinct final states at future colliders, e.g. tau mu + jets + missing energy. We discuss the role of chargino pair production for the LFV signals at e+e- colliders.

F. C. Lombardo, R. J. Rivers, F. D. Mazzitelli

We analyze the onset of classical field configurations after a phase transition. Firstly, we motivate the problem by means of a toy model in quantum mechanics. Subsequently, we consider a scalar field theory in which the system-field interacts with its environment, represented both by further scalar fields and by its own short-wavelength modes. We show that,

R. J. Rivers, F. C. Lombardo, F. D. Mazzitelli

Classical defects (monopoles, vortices, etc.) are a characteristic consequence of many phase transitions of quantum fields. Most likely these include transitions in the early universe and such defects would be expected to be present in the universe today. We continue our analysis of the onset of classical behaviour after a second-order phase transition in qu

V. I. Zakharov

We discuss implications of the recent measurements of the non-Abelian action density associated with the monopoles condensed in the confining phase of gluodynamics. The radius of the monopole determined in terms of the action was found to be small numerically. As far as the condensation of the monopoles is described in terms of a scalar field, a fine tuning

S. Y. Choi, J. Kalinowski, G. Moortgat--Pick, P. M. Zerwas

In the preceding reference [CKMZ] we have shown how the fundamental gaugino and higgsino parameters of the chargino and neutralino system in supersymmetric theories can be determined in high--precision experiments at $e^+e^-$ linear colliders. Within the Minimal Supersymmetric Standard Model these parameters can be reconstructed completely even if only the l

Masaaki Fujii, Koshiro Suzuki

Noscale supersymmetry (SUSY) breaking model is investigated in the minimal extension of the minimal supersymmetric standard model (MSSM) with a gauged U(1)_{B-L} symmetry. We specifically consider a unification-inspired model with the gauge groups SU(3)_{C} \times SU(2)_{L} \times U(1)_Y \times U(1)_{B-L} \subset SU(5) \times U(1)_{5} for illustration. While

G. C. Branco, T. Morozumi, B. M. Nobre, M. N. Rebelo

We discuss how CP violation generating lepton number asymmetry can be related to CP violation in low energy.

A. A. Belavin, S. Yu. Gubanov

We examine the XXZ model with generalized periodic boundary conditions and identify conditions for the truncation of the functional fusion relations of the transfer matrix fusion. After the truncation, the fusion relations become a closed system of functional equations. The energy spectrum can be obtained by solving these equations. We obtain the explicit fo

Andrew R Liddle

This article gives an overview, aimed at theoretical particle physicists, of some recent developments in cosmology.

Frank Wilczek

I discuss four big questions that can be importantly addressed using concepts from modern QCD. They concern the origin of mass, the feebleness of gravity, the uniqueness of physical laws, and the fate of matter when it is squeezed very hard.

A. Di Giacomo

A few aspects of the mechanism of confinement of color by monopole condensation are reviewed.

X. Q. Luo, E. Gregory, H. Xi, J. Yang

We describe the construction of a high performance parallel computer composed of PC components, as well as the performance test in lattice QCD.

Rajiv V. Gavai, Sourendu Gupta

We report the continuum limit of quark number susceptibilities in quenched QCD. Deviations from ideal gas behaviour at temperature T increase as the lattice spacing is decreased from T/4 to T/6, but a further decrease seems to have very little effect. The measured susceptibilities are 20% lower than the ideal gas values, and also 10% below the hard thermal l

Sourendu Gupta

We report an investigation of criticality in QCD at finite isovector chemical potential, mu_3, and at zero temperature. At the critical point, mu_3^c = m_pi, we find that an uncharged scalar and pseudoscalar and a charged pseudoscalar meson become massless within the resolution of our measurement. The effective long distance theory therefore breaks O(4) symm

Yvonne Choquet-Bruhat, James W. York

We establish a variant, which has the advantage of introducing only physical characteristics, of the symmetric quasi linear first order system given by H.\ Friedrich for the evolution equations of gravitating fluid bodies in General Relativity which can be important to solve realistic problems. We explicit the conditions under which the system is hyperbolic

Yvonne Choquet-Bruhat, James W. York

We review some old and new results about strict and non strict hyperbolic formulations of the Einstein equations.

Rommel Guerrero, Alejandra Melfo, Nelson Pantoja

We analyse the distributional thin wall limit of self gravitating scalar field configurations representing thick domain wall geometries. We show that thick wall solutions can be generated by appropiate scaling of the thin wall ones, and obtain an exact solution for a domain wall that interpolates between AdS_4 asymptotic vacua and has a well-defined thin wal

Ralf Metzler, Andreas Hanke, Paul G. Dommersnes, Yacov Kantor

We study the interplay between entropy and topological constraints for a polymer chain in which sliding rings (slip-links) enforce pair contacts between monomers. These slip-links divide a closed ring polymer into a number of sub-loops which can exchange length between each other. In the ideal chain limit, we find the joint probability density function for t

P. -E. Roche, M. Kociak, S. Gueron, A. Kasumov

We have performed noise measurements on suspended ropes of single wall carbon nanotubes (SWNT) between 1 and 300 K for different values of dc current through the ropes. We find that the shot noise is suppressed by more than a factor 100 compared to the full shot noise 2eI. We have also measured an individual SWNT and found a level of noise which is smaller t

Michael Kastner

Properties of the two dimensional Ising model with fixed magnetization are deduced from known exact results on the two dimensional Ising model. The existence of a continuous phase transition is shown for arbitrary values of the fixed magnetization when crossing the boundary of the coexistence region. Modifications of this result for systems of spatial dimens

A. Kuklov, A. E. Meyerovich

We explore analogy between two-component quantum alkali gases and spin-polarized helium systems. Recent experiments in trapped gases are put into the frame of the existing theory for Castaing instability in transverse channel and formation of homogeneous precessing domains in spin-polarized systems. Analogous effects have already been observed in spin-polari

E. H. Hwang, A. J. Millis, S. Das Sarma

The dynamical mean field method is used to calculate the frequency and temperature dependent conductivity of dilute magnetic semiconductors. Characteristic qualitative features are found distinguishing weak, intermediate, and strong carrier-spin coupling and allowing quantitative determination of important parameters defining the underlying ferromagnetic mec

Taro Nagao, Makoto Katori, Hideki Tanemura

Nonintersecting motion of Brownian particles in one dimension is studied. The system is constructed as the diffusion scaling limit of Fisher&#39;s vicious random walk. N particles start from the origin at time t=0 and then undergo mutually avoiding Brownian motion until a finite time t=T. In the short time limit $t \ll T$, the particle distribution is asympt

Kenji Ishii, Akihiko Fujiwara, Hiroyoshi Suematsu, Yoshihiro Kubozono

We have studied crystal structure, magnetism and electric transport properties of a europium fulleride Eu6C60 and its Sr-substituted compounds, Eu6-xSrxC60. They have a bcc structure, which is an isostructure of other M6C60 (M represents an alkali atom or an alkaline earth atom). Magnetic measurements revealed that magnetic moment is ascribed to the divalent

N. Kang, L. Lu, W. J. Kong, J. S. Hu

We have investigated the thermoelectric power (TEP) of millimeter-long aligned multiwall carbon nanotubes down to a temperature of $T$=1.5 K, and observed for the first time an accurate $T {\rm ln} T$ dependence at low temperatures. This behavior is possibly originated from the repulsive interaction between the electrons in a disordered local environment.

Yongjin Jiang, Haijin Li, Ruibao Tao

Using exact diagonalization method,we studied the ground state of the anisotropic molecular magnets and find a critical point in the transverse field,which may divide the quantum tunneling region into two different parts. Possible ways to observe and take advantage of this point by varying the transverse field are suggested.

Constantine Yannouleas, Uzi Landman

A new class of analytic and parameter-free, strongly correlated wave functions of simple functional form is derived for few electrons in two-dimensional quantum dots under high magnetic fields. These wave functions are constructed through breaking and subsequent restoration of the circular symmetry, and they offer a natural alternative to the Laughlin and co

Fa-Min Liu, C. Dong, J. Q. Li, T. M. Wang

Polycrystalline Mg(1-x)Al(x)B(2) (x = 0, 0.1, 0.4, 0.5, 0.6, 1) samples have been prepared by a conventional solid state reaction. The Mg 2p, Al 2p and B 1s core level binding energies have been studied using X-ray photoemission spectroscopy (XPS). It is found that Mg 2p, Al 2p and B 1s core level binding energies increase with the Al content in Mg(1-x)Al(x)

Sergey Langvagen

A hysteresis model based on the assumption of fixed order magnetization reversals is proposed. The model uses one-dimensional diagram for representing states of a system despite of two-dimensional Preisach diagram. The distinctive feature of the model is that it is applicable to any system compliant with the return-point memory and includes Preisach model as

Ilya Nemenman, William Bialek

Learning of a smooth but nonparametric probability density can be regularized using methods of Quantum Field Theory. We implement a field theoretic prior numerically, test its efficacy, and show that the data and the phase space factors arising from the integration over the model space determine the free parameter of the theory (&#34;smoothness scale&#34;) s