August 1998 arXiv papers — page 18

Daniel Z. Freedman, Samir D. Mathur, Alec Matusis, Leonardo Rastelli

We study the four--point function of chiral primaries corresponding to the dilaton--axion sector in supergravity in the $AdS_5$/CFT$_4$ correspondence. We find relations between some of the supergravity graphs and compute their leading singularities. We discuss the issue of logarithmic singularities and their significance for the OPE structure of the CFT.

H. Belich, R. Paunov

Affine Toda equations based on simple Lie algebras arise by imposing zero curvature condition on a Lax connection which belongs to the corresponding loop Lie algebra in the principal gradation. In the particular case of $A_n^{(1)}$ Toda models, we exploit the symmetry of the underlying linear problem to calculate the dressing group element which generates ar

Keith Johnson

Possible chemical, catalytic, and cosmic roles of charged pentagonal dodecahedral water clusters having "buckyball-like" symmetry are discussed on the basis of electronic and vibronic theory and experiment. The electronic structure in conjunction with the dynamic Jahn-Teller effect is argued to make water buckyballs catalysts and oxygenates for fuel

Qing Hou, Shin-ichi Sasa, Nigel Goldenfeld

We study the kinetics of phase transitions in a Rayleigh-Benard system after onset of convection using 2D Swift-Hohenberg equation. An initially uniform state evolves to one whose ground state is spatially periodic. We confirmed previous results which showed that dynamical scaling occurs at medium quench ($ε= 0.25$) with scaling exponents 1/5 and 1/4 under z

U. van Kolck

The method of effective field theories (EFTs) is developed for the scattering of two particles at wavelengths which are large compared to the range of their interaction. It is shown that the renormalized EFT is equivalent to the effective range expansion, to a Schroedinger equation with a pseudo-potential, and to an energy expansion of a generic boundary con

Georg Wagner, A. J. Buchmann, Amand Faessler

We calculate the radiative decay widths of decuplet hyperons in a chiral constituent quark model including electromagnetic exchange currents between quarks. Exchange currents contribute significantly to the E2 transition amplitude, while they largely cancel for the M1 transition amplitude. Strangeness suppression of the radiative hyperon decays is found to b

A. Botvina, D. H. E. Gross

We point out some basic misunderstandings and wrong statements about our microcanonical Metropolis Monte Carlo (MMMC) model of nuclear fragmentation.

Barbara Niethammer, Robert L. Pego

The LSW theory of Ostwald ripening concerns the time evolution of the size distribution of a dilute system of particles that evolve by diffusional mass transfer with a common mean field. We prove global existence, uniqueness and continuous dependence on initial data for measure-valued solutions with compact support in particle size. These results are establi

Michael Yampolsky, Saeed Zakeri

Let F be a quadratic rational map of the sphere which has two fixed Siegel disks with bounded type rotation numbers theta and nu. Using a new degree 3 Blaschke product model for the dynamics of F and an adaptation of complex a priori bounds for renormalization of critical circle maps, we prove that F can be realized as the mating of two Siegel quadratic poly

Dusa McDuff

In this note we investigate the structure of the space $\Jj$ of smooth almost complex structures on $S^2\times S^2$ that are compatible with some symplectic form. This space has a natural stratification that changes as the cohomology class of the form changes and whose properties are very closely connected to the topology of the group of symplectomorphisms o

S. Bouarroudj, V. Ovsienko

We introduce a 1-cocycle on the group of diffeomorphisms Diff$(M)$ of a smooth manifold $M$ endowed with a projective connection. This cocycle represents a nontrivial cohomology class of $\Diff(M)$ related to the Diff$(M)$-modules of second order linear differential operators on $M$. In the one-dimensional case, this cocycle coincides with the Schwarzian der

Kirill C. H. Mackenzie

We prove that the cotangent of a double Lie groupoid S has itself a double groupoid structure with sides the duals of associated Lie algebroids, and double base the dual of the Lie algebroid of the core of S. Using this, we prove a result outlined by Weinstein in 1988, that the side groupoids of a general symplectic double groupoid are Poisson groupoids in d

Arthur W. Apter, Joel David Hamkins

From a suitable large cardinal hypothesis, we provide a model with a supercompact cardinal in which universal indestructibility holds: every supercompact and partially supercompact cardinal kappa is fully indestructible by kappa-directed closed forcing. Such a state of affairs is impossible with two supercompact cardinals or even with a cardinal which is sup

Masatoshi Noumi, Yasuhiko Yamada

A series of systems of nonlinear equations with affine Weyl group symmetry of type $A^{(1)}_l$ is studied. This series gives a generalization of Painlevé equations $P_{IV}$ and $P_{V}$ to higher orders.

Yasuhiko Yamada

Explicit determinant formulas are presented for the $τ$ functions of the generalized Painlevé equations of type $A$. This result allows an interpretation of the $τ$-functions as the Plücker coordinates of the universal Grassmann manifold.

H. Reinhardt

Lattice calculations performed in Abelian gauges give strong evidence that confinement is realized as a dual Meissner effect, implying that the Yang--Mills vacuum consists of a condensate of magnetic monopoles. We show in Polyakov gauge how the Pontrjagin index of the gauge field is related to the magnetic monopole charges.

S. Maedan

Dynamical Higgs mechanism on the light-front (LF) is studied using a (1+1) dimensional model, with emphasis on the infrared divergence problem. The consideration of the zero mode $ k^+ = 0 $ is not sufficient for investigating dynamical symmetry breaking on the LF. It also needs to treat properly an infrared divergence caused by internal momentum $ p^+ \to 0

Feng-Li Lin

If cosmological constant is positive, a black hole is naturally described by the Schwarzschild-de Sitter solution with two horizons. We use the global method to extract the topological information and the selection rule for the Gibbons-Hawking temperature for the thermal vacua. These are related to the Euler number of the Euclidean section whose topology is

Z. Lin, R. Vogt

We study the effect of energy loss on charm and bottom quarks in high-energy heavy-ion collisions including hadronization, longitudinal expansion and partial thermalization. We consider in detail the detector geometry and single lepton energy cuts of the ALICE and CMS detectors at the Large Hadron Collider (LHC) to show the large suppression of high $p_T$ he

T. Gutierrez, R. Vogt

Leading charm hadrons produced in hadron-nucleus interactions cannot be adequately described within the parton fusion model. Recent results on charm baryon production in $Σ^- A$ interactions at 330 GeV with the WA89 detector disagree with fusion predictions. Intrinsic heavy quark pairs in the $Σ^-(dds)$ wavefunction provide a simple mechanism for producing f

J. Bernabeu, M. C. Banuls

Recently a rephasing invariant definition of the CP-mixing parameter for Indirect CP Violation has been introduced. This is made possible by the explicit use of the CP operator into the analysis. The problem is then that of the determination of the CP operator for a CP violating scenario. We discuss it and provide a definite solution.

Ali Abbasabadi, Alberto Devoto, Duane A. Dicus, Wayne W. Repko

A general decomposition of the amplitudes for the $2\to 2$ processes $γν\toγν$ and $γγ\toν\barν$ is obtained using gauge invariance and Bose symmetry. The restrictions implied by this decomposition are investigated for the reaction $γγ\toν\barν$ by computing the one-loop helicity amplitudes in the standard model. In the center of mass, where $\sqrt{s} = 2ω$,

M. E. Sainio

A brief discussion of the elastic pion-pion scattering amplitude to two loops in chiral perturbation theory is given. Some technical details of the evaluation of two-loop diagrams are addressed, and results relevant for the pionium decay are presented.

A. V. Nefediev

The system of light quark and heavy anti-quark source is studied in 1+1 QCD in the large $N_C$ limit. Making use of the modified Fock-Schwinger gauge allows to consider simultaneously the spectroscopical problem of the q\bar Q bound states and the problem of the light quark Green function. The Dirac-type equation for the spectrum of the system is proved to b

Wojciech Krolikowski

It is argued that the observed deficit of solar and atmospheric neutrinos can be explained by neutrino oscillations $ν_e \to ν_s $ and $ν_μ\to ν'_{s}$ involving two hypothetic sterile neutrinos $ν_s $ and $ν'_{s} $ (blind to all Standard--Model interactions). They are keen to mix nearly maximally with $ν_{e}$ and $ν_μ$, respectively, to form neutrino

Aleksey I. Alekseev

Nonperturbative studies of the strong running coupling constant in the infrared region are discussed. Starting from the analyses of the Dyson -- Schwinger equations in the gauge sector of QCD, the conclusion is made on an incomplete fixing of the perturbation theory summation ambiguity within "(forced) analytization procedure" (called also a dispersi

G. L. Fogli, E. Lisi, A. Marrone, G. Scioscia

We present a detailed analysis of the zenith angle distributions of atmospheric neutrino events observed in the Super-Kamiokande (SK) underground experiment, assuming two-flavor and three-flavor oscillations (with one dominant mass scale) among active neutrinos. In particular, we calculate the five angular distributions associated to sub-GeV and multi-GeV μ-

A. De Angelis, L. Vitale

To estimate the strength of the Bose-Einstein correlations and the radius of the hadronization region in multiparticle production, the two-particle correlation functions $R$ for identical pairs is adjusted to a parametric function describing the enhancement at small momentum differences. This is usually done by means of a binned uncorrelated least squares fi

J. C. Fabris, S. V. B. Goncalves

We study the tensorial modes of the two-fluid model, where one of this fluids has an equation of state $p = - ρ/3$ (variable cosmological constant, cosmic string fluid, texture) or $p = - ρ$ (cosmological constant), while the other fluid is an ordinary matter (radiation, stiff matter, incoherent matter). In the first case, it is possible to have a closed Uni

P. Fiziev

We present a review of some recent models of gravitation theory with propagating torsion based on the use of a torsion-dilaton field and propose one more model of this type which promises to be more realistic. A proper universal self-consistent minimal action principle yields the properties of this model and predicts the interactions of torsion-dilaton field

M. A. Clayton

Building on the results of previous work, we demonstrate how matter fields are incorporated into the general linear frame approach to general relativity. When considering the Maxwell one-form field, we find that the system that leads naturally to canonical vierbein general relativity has the extrinsic curvature of the Cauchy surface represented by gravitatio

C. Kohler

A modification of Kaluza-Klein theory is proposed in which, as a result of a symmetry breaking, five-dimensional space-time is partially parallelized implying the appearance of torsion fields. A naturally chosen action functional leads to the Einstein-Cartan-Maxwell theory where the electromagnetic field strength is represented by the fifth component of the

D. V. Gal'tsov

A recent progress in obtaining non-spherical and non-static solitons in the four-dimensional Einstein--Yang--Mills (EYM) theory is discussed, and a non-perturbative formulation of the stationary axisymmetric problem is attempted. First a 2D dilaton gravity model is derived for the spherically symmetric time-dependent configurations. Then a similar Euclidean

Hiroshi Hasegawa, Baowen Li, Jian-Zhong Ma, Bambi Hu

We have computed the spectral number variances of an extended random matrix ensemble predicted by Guhr's supersymmetry formula, showing a non-monotone increase of the curves that arises from an "overshoot" of the two-level correlation function above unity. On the basis of the most general form of $N$-level joint distribution that meets sound prob

Beat Frischmuth, Manfred Sigrist, Beat Ammon, Matthias Troyer

Using the quantum Monte Carlo Loop algorithm, we calculate the temperature dependence of the uniform susceptibility, the specific heat, the correlation length, the generalized staggered susceptibility and magnetization of a spin-1/2 chain with random antiferromagnetic and ferromagnetic couplings, down to very low temperatures. Our data show a consistent scal

G. Fagas, A. G. Kozorezov, C. J. Lambert, J. K. Wigmore

For an fcc crystal with central force interactions and separately for a scalar model on a square lattice, we compute exactly the phonon transmission coefficient $T(ω)$ through a disordered planar interface between two identical semi - infinite leads. At high frequencies $T(ω)$ exhibits a strong frequency dependence which is determined by the correlation leng

G. Fagas, Vladimir I. Fal'ko, C. J. Lambert

We study spectral statistics of lattice modes in a disordered crystal and in a crystal with a complex unit cell. The correlations of the eigenmode frequencies of a block of a disordered solid is found to obey the GOE Wigner-Dyson statistics. In contrast, the set of eigenfrequencies of a crystal with a complex unit cell taken at the same point ${\bf Q}\not=0$

Erwin Frey, Klaus Kroy, Jan Wilhelm

Living cells are soft bodies of a characteristic form, but endowed with a capacity for a steady turnover of their structures. Both of these material properties, i.e. recovery of the shape after an external stress has been imposed and dynamic structural reorganization, are essential for many cellular phenomena. Examples are mechanical properties of tissue, ce

S. De Toro Arias, J. M. Luck

We investigate dynamical scaling properties of the 1D tight-binding Anderson model with a weak diagonal disorder, by means of the spreading of a wave packet. In the absence of disorder, and more generally in the ballistic regime, the wavefunction exhibits sharp fronts. These ballistic fronts yield an anomalous time dependence of the $q$-th moment of the loca

R. M. Noack, M. G. Zacher, H. Endres, W. Hanke

Using quantum Monte Carlo (QMC) simulations combined with Maximum Entropy analytic continuation as well as analytical methods, we examine the one- and two-particle dynamical properties of the Hubbard model on two coupled chains at small doping. The behavior of the single-particle spectral weight $A({\bf k},ω)$ as a function of hopping anisotropy $t_\perp/t$

Xavier Leoncini, Alberto D. Verga, Stefano Ruffo

A Hamiltonian dynamics is defined for the XY model by adding a kinetic energy term. Thermodynamical properties (total energy, magnetization, vorticity) derived from microcanonical simulations of this model are found to be in agreement with canonical Monte-Carlo results in the explored temperature region. The behavior of the magnetization and the energy as fu

Fabian H. L. Essler, Vladimir E. Korepin

We consider dynamical spin-spin correlation functions in the one dimensional repulsive half-filled Hubbard model. We propose an exact expression for the two spinon formfactor of spin operators. We use this to derive the two spinon contribution to the dynamical structure factor.

M. Bahiana, Belita Koiller, S. L. A. de Queiroz, J. C. Denardin

The possible existence of self-organized criticality in Barkhausen noise is investigated theoretically through a single interface model, and experimentally from measurements in amorphous magnetostrictive ribbon Metglas 2605TCA under stress. Contrary to previous interpretations in the literature, both simulation and experiment indicate that the presence of a

Shu Chen, Yupeng Wang, Fan Yang, Fu-Cho Pu

We investigate an interacting fermion model with boundary potential by using Bethe ansatz method. The ground state properties of the system and the boundary effect are discussed. It is found that attractive boundary potential leads to the boundary bound state. An interesting phenomenon is that the slidding collective charges in a periodic system, which is fo

E. Orignac, T. Giamarchi

The effect of a weak random potential on two-leg Hubbard ladders is investigated. The random potential is shown to induce Anderson localization except for attractive enough interactions, supressing completely d-wave superconductivity. These localization effects remain very strong even for many ladders coupled by Josephson coupling. Both dc and ac conductivit

Yunkyu Bang

Assuming a phenomenological self-energy $Im Σ(ω) \sim |ω|^{β\}, (β=1 $), which becomes gapped below $T_c$, we derived a new gap equation. The new gap equation contains the effect of the kinetic energy gain upon developing a superconducting order parameter. However, this new kinetic energy gain mechanism works only for a repulsive pairing potential leading to

Iddo Ussishkin, Ady Stern

We consider the Coulomb drag between two two-dimensional electron layers at filling factor ν= 1/2 each, using a strong coupling approach within the composite fermion picture. Due to an attractive interlayer interaction, composite fermions are expected to form a paired state below a critical temperature T_c. We find that above T_c pairing fluctuations make th

C. Stampfl, K. Kambe, R. Fasel, P. Aebi

Using Kohn-Sham wave functions and their energy levels obtained by density-functional-theory total-energy calculations, the electronic structure of the two c(2x2) phases of Na on Al(001) are analysed; namely, the metastable hollow-site structure formed when adsorption takes place at low temperature, and the stable substitutional structure appearing when the

R. Everaers, F. Julicher, A. Ajdari, A. C. Maggs

We develop a scaling theory to describe dynamic fluctuations of a semiflexible polymer and find several distinct regimes. We performed simulations to characterize the longitudinal and transverse dynamics; using ensemble averaging for a range of different degrees of coarse-graining we avoid the problems of slow equilibration often encountered in simulations.

S. N. Dorogovtsev

The dynamics of the avalanche mixing in a slowly rotated 2D upright drum is studied in the situation where the difference $δ$ between the angle of marginal stability and the angle of repose of the granular material is finite. An analytical solution of the problem is found for a half filled drum, that is the most interesting case. The mixing is described by a

R. N. Ogley, S. J. Bell Burnell, R. P. Fender, G. G. Pooley

Multi-wavelength photometric observations of Cygnus X-3 were carried out at 18 cm through to 450 um, complemented by X-ray (2-10 keV) observations. The system was mildly active with cm fluxes at 150 -- 250 mJy. We find the spectrum to be flat with a spectral index of zero. Using a modified Wolf-Rayet wind model, and assuming emission is generated in synchrot

Max Pettini, Sara L. Ellison, Charles C. Steidel, David V. Bowen

We explore the redshift evolution of the metal content of damped Lyman alpha systems (DLAs) with new observations of four absorbers at z < 1.5 . The main conclusion is that the column density--weighted mean metallicity, [<Zn/H>] = -1.03 +/- 0.23 (on a logarithmic scale), is not significantly higher at z < 1.5 than at earlier epochs, despite the fact that the

A. F. Heavens, S. Matarrese, L. Verde

We study the power spectrum of galaxies in redshift space, with third order perturbation theory to include corrections that are absent in linear theory. We assume a local bias for the galaxies: i.e. the galaxy density is sampled from some local function of the underlying mass distribution. We find that the effect of the nonlinear bias in real space is to int

P. Laurent, L. Titarchuk

An accreting black hole is, by definition, characterized by the drain. Namely, the matter falls into a black hole much the same way as water disappears down a drain - matter goes in and nothing comes out. As this can only happen in a black hole, it provides an unique way to see it. The accretion proceeds almost in free fall close to the black hole horizon. I

B. Czerny, A. -M. Dumont

We assume a distribution of clouds optically thick for electron scattering (OTCM) which are moderately optically thin for absorption and we consider them as a model of the mean quasar spectrum of Laor et al. (1997). We show that the model is particularly sensitive to the value of the ionization parameter $ξ$ and that for $ξ\sim 500$ the model well reproduces

M. Turatto, A. Piemonte, S. Benetti, E. Cappellaro

Observations of the recent SN 1991bg in the elliptical galaxy NGC 5490 show that this objects closely resembles, both photometrically and spectroscopically, the faint SNIa 1991bg. The two objects have similar light curves, which do not show secondary maxima in the near IR as normal type Ia supernovae. The host galaxy, NGC5490, lies in the Hubble flow. Adopti

R. Fusco-Femiano, D. Dal Fiume, L. Feretti, G. Giovannini

We present first results of the BeppoSAX observation of the Coma Cluster. Thanks to the unprecedented sensitivity of the PDS instrument, the source has been detected up to ~80 keV. There is clear evidence for emission in excess to the thermal one above ~25 keV, very likely of non-thermal origin. We have therefore, for the first time, detected the long sought

G. Fiorentini, M. Lissia, B. Ricci

We present a quantitative estimate of the accuracy of the calculated diffusion coefficients, by comparing predictions of solar models with observational data provided by helioseismology. By taking into account the major uncertainties in building solar models we conclude that helioseismology confirms the diffusion efficiency adopted in SSM calculations, to th

M. Guainazzi, A. Comastri, G. M. Stripe, W. N. Brandt

In this paper we report on the first simultaneous optical and X-ray (Beppo-SAX) observations of the radio-quiet AGN 1H0419-577. The optical spectrum clearly leads us to classify this source as a Seyfert 1. The X-ray spectrum is, however, somewhat at odds with this classification: a simple flat (Gamma ~ 1.55) and featureless power--law is a good description o

Jonathan Granot, Tsvi Piran, Re&#39;em Sari

GRB afterglow is reasonably described by synchrotron emission from relativistic blast waves at cosmological distances. We perform detailed calculations taking into account the effect of synchrotron self absorption. We consider emission from the whole region behind the shock front, and use the Blandford McKee self similar solution to describe the fluid behind

Daniele Fargion

The GRB980425-SN1998bw association put in severe strain and contradiction the simplest &#34;candle&#34; fireball model for GRBs. We probed that statistically the association is reliable, the energy luminosity and probability puzzles between cosmic and near by GRBs find a solution within a precessing gamma jet model either for GRBs and SGRs. The expected repe

R. Wielen, H. Schwan, C. Dettbarn, H. Jahreiss

The Sixth Catalogue of Fundamental Stars (FK6) combines the ground-based astrometric data of the basic fundamental stars, obtained over more than two centuries and summarized in the FK5, with the observations of the HIPPARCOS astrometry satellite. This combination provides the most accurate proper motions available at present. There are two main reasons why

R. Wielen, H. Schwan, C. Dettbarn, H. Jahreiss

The combination of HIPPARCOS measurements with suitable ground-based astrometric data improves significantly the accuracy of the proper motions of bright stars. The comparison of both types of data allows us also to identify and to eliminate, at least partially, cosmic errors in the quasi-instantaneously measured HIPPARCOS data which are caused by undetected

Eric G. Blackman

Two-temperature advection dominated accretion flow (ADAF) or hot ion tori (HIT) models help explain low luminosity stellar and galactic accreting sources and may complement observational support for black holes in nature. But low radiative efficiencies demand that ions receive a fraction $η\gsim 99%$ of energy dissipated in the turbulent accretion. The $η$ d

Lior Goldenberg, Lev Vaidman, Stephen Wiesner

We present a two-party protocol for quantum gambling, a new task closely related to coin tossing. The protocol allows two remote parties to play a gambling game, such that in a certain limit it becomes a fair game. No unconditionally secure classical method is known to accomplish this task.

D. Anselmi

We study higher spin tensor currents in quantum field theory. Scalar, spinor and vector fields admit unique &#34;improved&#34; currents of arbitrary spin, traceless and conserved. Off-criticality as well as at interacting fixed points conservation is violated and the dimension of the current is anomalous. In particular, currents J^(s,I) with spin s between 0

G. Gabadadze

We find an expression for the effective superpotential describing the $N_c$ vacua of $SU(N_c)$ SUSY gluodynamics. The superpotential reduces in some approximation to the Veneziano-Yankielowicz expression amended by the term restoring the discrete $Z_{2N_c}$ symmetry. Moreover, the superpotential, being restricted to one particular vacuum state, yields the ex

Varun Sahni, Salman Habib

We study a class of FRW spacetimes with a nonminimally coupled light massive scalar field. Values of the coupling parameter xi<0 enhance long range power in the vacuum expectation value of the energy-momentum tensor and fundamentally alter the nature of inflationary particle production: the energy density of created particles behaves like an effective cosmol

M. C. Gonzalez-Garcia

I summarize here the results of a global fit to the full data set corresponding to 535 days of data of the Super-Kamiokande experiment as well as to all other experiments in order to compare the two most likely solutions to the atmospheric neutrino anomaly in terms of oscillations in the $ν_μ\to ν_τ$ and $ν_μ\to ν_s$ channels.

Bo-Qiang Ma, Ivan Schmidt

We perform an analysis of the quark angular momentum in a light-cone representation by taking into account the effect due to the Melosh-Wigner rotation and find that there is a relativistic correction factor connecting the quark orbital angular momentum with the quark model spin distribution: $L_q(x)={<M_L(x)>}Δq_{QM}(x)$. The quark orbital angular momentum

J. W. Maluf, J. F. da Rocha Neto

The Hamiltonian formulation of general relativity on a null surface is established in the teleparallel geometry. No particular gauge conditons on the tetrads are imposed, such as the time gauge condition. By means of a 3+1 decomposition the resulting Hamiltonian arises as a completely constrained system. However, it is structurally different from the the sta

Salman Habib, Avinash Khare, Avadh Saxena

We study the classical thermodynamics of the double sinh-Gordon (DSHG) theory in 1+1 dimensions. This model theory has a double well potential, thus allowing for the existence of kinks and antikinks. Though it is nonintegrable, the DSHG model is remarkably amenable to analysis. Below we obtain exact single kink and kink lattice solutions as well as the asymp

D. Smirnov, J. Leotin, P. Millet, J. Jegoudez

Infrared reflectance of alpha&#39;-NaV2O5 single crystals in the frequency range from 50 cm-1 to 10000 cm-1 was studied for a, b and c-polarisations. In addition to phonon modes identification, for the a-polarised spectrum a broad continuum absorption in the range of 1D magnetic excitation energies was found. The strong near-IR absorption band at 0.8 eV show

Zhou Haijun, Ou-Yang Zhong-can

During catastrophic processes of environmental variations of a thermodynamic system, such as rapid temperature decreasing, many novel and complex patterns often form. To understand such phenomena, a general mechanism is proposed based on the competition between heat transfer and conversion of heat to other energy forms. We apply it to the smectic-A filament

Sang-Yoon Kim

Using a renormalization method, we study the critical behavior for intermittency in two coupled one-dimensional (1D) maps. We find two fixed maps of the renormalization transformation. They all have common relevant eigenvalues associated with scaling of the control parameter of the uncoupled 1D map. However, the relevant ``coupling eigenvalues&#39;&#39; asso

Y. D. Mayya, Swara Ravindranath, L. Carrasco

Near infrared (NIR) and optical surface photometric analyses of the dusty galaxy NGC972 are presented. The photometric profiles in the BVRJHK bands can be fitted with a combination of gaussian and exponential profiles, corresponding to a starburst nucleus and a stellar disk respectively. The exponential scale length in the B-band is 2.8 times larger than in

Piotr Popowski, Andrew Gould

We review seven methods of measuring the absolute magnitude M_V of RR Lyrae stars in light of the Hipparcos mission and other recent developments. We focus on identifying possible systematic errors and rank the methods by relative immunity to such errors. For the three most robust methods, statistical parallax, trigonometric parallax, and cluster kinematics,

P. Faccioli, M. Traini, V. Vento

We present a consistent calculation of the structure functions within a light-front constituent quark model of the nucleon. Relativistic effects and the relevance of the covariance constraints are analyzed for both polarized and unpolarized parton distributions. Various models, which differ in their gluonic structure at the hadronic scale, are investigated.

T. Senthil, Matthew P. A. Fisher, Leon Balents, Chetan Nayak

We present a theory of the effects of impurity scattering in d_{x^2-y^2} superconductors and their quantum disordered counterparts, based on a non-linear sigma model formulation. We show the existence, in a quasi-two-dimensional system, of a novel spin-metal phase with a non-zero spin diffusion constant at zero temperature. With decreasing inter-layer coupli

Douglas Scott, Martin White

We investigate the implications for the Planck Surveyor of the recent sub-millimetre number counts obtained using the SCUBA camera. Since it observes at the same frequency as one of the higher frequency science channels on Planck, SCUBA can provide constraints on the point-source contribution to the CMB angular power spectrum, which require no extrapolation

Dongsu Bak, Sang Pyo Kim, Sung Ku Kim, Kwang-Sup Soh

We have developed a variational perturbation theory based on the Liouville-Neumann equation, which enables one to systematically compute the perturbative correction terms to the variationally determined wave functions of the time-dependent systems. We then apply the method to the time-independent anharmonic oscillator, and show that the results agree with th

Serban Misicu, A. Sandulescu, F. Carstoiu, M. Rizea

We compute the final kinetic energies of the fragments emitted in the light charged particle accompanied cold fission of $^{252}$Cf taking into account the ground state quadrupole deformation and the finite-size effects of the fragments and integrating the equations of motion for a three-body system subjected only to Coulomb forces. The initial conditions fo

S. Misicu, N. Carjan, P. Talou

Based on a single particle model which describes the time evolution of the wave function during tunneling across a one dimensional potential barrier we study the proton decay of $^{208}$Pb from excited states with non-vanishing angular momentum $\ell$. Several quantities of interest in this process like the decay rate $λ$, the period of oscillation $T_{osc}$

Hélène Esnault, Eckart Viehweg

This note is an attempt to generalize Bolibruch&#39;s theorem from the projective line to curves of higher genus. We show that an irreducible representation of the fundamental group of an open in a curve of higher genus has always a representation as a regular system of differential equations on a semistable bundle of degree 0. Vice-versa, we show that given

E. Abdalla, R. Banerjee, C. Molina

We compute the quark--antiquark potential in three dimensional massive Quantum Electrodynamics for arbitrary fermion mass. The result indicates that screening prevails for any quark masses, contrary to the classical expectations, generalizing our previous result obtained for large masses. We also test the validity of several approximation schemes using a det

H. W. Lee, Y. S. Myung

We propose a new method to calculate the greybody factor in the $AdS_3$. This is based on both the non-normalizable modes of a test field($Φ_i$) and $AdS_3$/CFT correspondence. Such non-normalizable modes serve as classical, non-fluctuating background and encode the choice of operator insertion(${\cal O}^i$) in the boundary. Actually specifying the boundary

M. Spurio

The flux of low energy neutrinos (<E_nu>~ 4 GeV) has been studied with the MACRO detector at Gran Sasso via the detection of muon neutrinos interactions inside the apparatus, and of upward-going stopping muons. Data collected in ~3 y with the full apparatus were analyzed. The results are compatible with a deficit of the flux of atmospheric muon neutrinos fro

M. L. Littman, J. Goldsmith, M. Mundhenk

We examine the computational complexity of testing and finding small plans in probabilistic planning domains with both flat and propositional representations. The complexity of plan evaluation and existence varies with the plan type sought; we examine totally ordered plans, acyclic plans, and looping plans, and partially ordered plans under three natural def

P. B. Wiegmann

There is a class of electronic liquids in dimensions greater than one, which show all essential properties of one dimensional electronic physics. These are topological liquids - correlated electronic systems with a spectral flow. Compressible topological electronic liquids are superfluids. In this paper we present a study of a conventional model of a topolog

B. I. Belevtsev, Yu. F. Komnik, E. Yu. Beliayev

The analysis of quantum corrections to magnetoconductivity of thin Au films responsible for by the effect of weak electron localization has made it possible to determine the temperature dependences of electron phase relaxation time in the temperature range 0.5--50 K for different degrees of crystal lattice disorder. The disorder was enhanced by irradiating t

Jahanshah Davoudi, Shahin Rouhani

We derive the asymptotic behaviour of the one point probability density for the inhomogeneous shock slopes in the turbulent regime, when a Gaussian fluctuating flux at origin derives the system. We also calculate the time dependence of the $x_{f}$ beyond which there won&#39;t exists any velocity shocks as $ x_{f}\cong t^{3/4}{(log{t})}^{1\4}$. We argue that

V. Gurarie, A. Zee

This preprint has been withdrawn as crucial errors have been discovered in the papers it has referred to. It is now superseded by cond-mat/9807391.

Marc Kamionkowski

Slow-roll inflation generically makes several predictions: a flat Universe, primordial adiabatic density perturbations, and a stochastic gravity-wave background. Each inflation model will further predict specific relations between the amplitudes and shapes of the spectrum of density perturbations and gravity waves. There are now excellent prospects for testi

Alexey Vikhlinin

We search for faint X-ray bursts with duration 10--300 seconds in the ROSAT PSPC pointed observations with a total exposure of 1.6e7 seconds. We do not detect any events shorter than ~100s, i.e. those that could be related to the classic gamma-ray bursts. At the same time, we detect a number of long flares with durations of several hundred seconds. Most, but

Schuyler D. Van Dyk, Daniel Puche, Tony Wong

We investigate the relationship between the spatial distributions of stellar populations and of neutral and ionized gas in the Local Group dwarf irregular galaxy Sextans A. This galaxy is currently experiencing a burst of localized star formation, the trigger of which is unknown. We have resolved various populations of stars via deep UBV(RI)_C imaging over a