March 1998 arXiv papers — page 2

D. Bennett-Wood, I. G. Enting, D. S. Gaunt, A. J. Guttmann

We present analyses of substantially extended series for both interacting self-avoiding walks (ISAW) and polygons (ISAP) on the square lattice. We argue that these provide good evidence that the free energies of both linear and ring polymers are equal above the theta-temperature, extending the application of a theorem of Tesi et. al. to two dimensions. Below

A. P. Potylitsin

An approach has been developed where the Smith-Purcell radiation (SPR), i.e. emission of electrons moving close to a periodic structure, is treated as the resonant diffraction radiation. Simple formulas have been designed for the SPR intensity for a grating having perfectly conducting strips spaced by a vacuum gap. The results have been compared with those o

Gunn A. Quznetsov

Four global gauge transformation of the free fermion Lagrangian is considered. One of these transformations has S(1) symmetry, other transformation has SU(2) symmetry, and two others have SU(3) symmetry. It is supposed, that these transformations determine four grades of the physics interactions - electromagnetic, weak, gravitational and chromatic.

J. A. de Azcarraga, J. M. Izquierdo, J. C. Perez Bueno

After a self-contained introduction to Lie algebra cohomology, we present some recent applications in mathematics and in physics. Contents: 1. Preliminaries: L_X, i_X, d 2. Elementary differential geometry on Lie groups 3. Lie algebra cohomology: a brief introduction 4. Symmetric polynomials and higher order cocycles 5. Higher order simple and SH Lie algebra

Feng Pan, Shi-hai Dong, J. P. Draayer

Induced representations of Brauer algebra $D_{f}(n)$ from $S_{f_{1}}\times S_{f_{2}}$ with $f_{1}+f_{2}=f$ are discussed. The induction coefficients (IDCs) or the outer-product reduction coefficients (ORCs) of $S_{f_{1}}\times S_{f_{2}}\uparrow D_{f}(n)$ with $f\leq 4$ up to a normalization factor are derived by using the linear equation method. Weyl tableau

P. Flanders, S. Gov, S. Shtrikman, H. Thomas

In this paper we analyze the spinning motion of the hovering magnetic top. We have observed that its motion looks different from that of a classical top. A classical top rotates about its own axis which precesses around a vertical fixed external axis. The hovering magnetic top, on the other hand, has its axis slightly tilted and moves rigidly as a whole abou

Peter Braun-Munzinger, Johanna Stachel

We review, from an experimental point of view, the current status of ultra-relativistic nuclear collisions with heavy beams.

Michael Kapovich, John J. Millson

We prove realizability theorems for vector-valued polynomial mappings, real-algebraic sets and compact smooth manifolds by moduli spaces of planar linkages. We also establish a relation between universality theorems for moduli spaces of mechanical linkages and projective arrangements.

V. Manuilov

We define for discrete finitely presented groups a new property related to their asymptotic representations. Namely we say that a groups has the property AGA if every almost representation generates an asymptotic representation. We give examples of groups with and without this property. For our example of a group $G$ without AGA the group $K^0(BG)$ cannot be

N. Aizawa

Tensor operators for the Jordanian quantum algebra Uh(sl(2)) are considered. Some explicit examples of them, which are obtained in the boson or fermion realization, are given and their properties are studied. It is also shown that the Wigner-Eckart's theorem can be extended to Uh(sl(2)).

T. H. Baker, P. J. Forrester

We study multivariable (bilateral) basic hypergeometric series associated with (type $A$) Macdonald polynomials. We derive several transformation and summation properties for such series including analogues of Heine's ${}_2ϕ_1$ transformation, the $q$-Pfaff-Kummer and Euler transformations, the $q$-Saalschütz summation formula and Sear's transformati

E. J. Beggs, P. R. Johnson

New single soliton solutions to the affine Toda field theories are constructed, exhibiting previously unobserved topological charges. This goes some of the way in filling the weights of the fundamental representations, but nevertheless holes in the representations remain. We use the group doublecross product form of the inverse scattering method, and restric

Oswaldo M. Del Cima, Daniel H. T. Franco, Jose A. Helayel-Neto, Olivier Piguet

The ``extended'' BF-Yang-Mills theory in 3 dimensions, which contains a minimally coupled scalar field, is shown to be ultraviolet finite. It obeys a trivial Callan-Symanzik equation, with all beta-functions and anomalous dimensions vanishing. The proof is based on an anomaly-free trace identity valid to all orders of perturbation theory.

J. Novotny, M. Schnabl

The point-splitting regularization technique for composite operators is discussed in connection with anomaly calculation. We present a pedagogical and self-contained review of the topic with an emphasis on the technical details. We also develop simple algebraic tools to handle the path ordered exponential insertions used within the covariant and non-covarian

E. Ragoucy, P. Sorba

We construct an algebra homomorphism between the Yangian Y(sl(n)) and the finite W-algebras W(sl(np),n.sl(p)) for any p. We show how this result can be applied to determine properties of the finite dimensional representations of such W-algebras.

E. Ragoucy, P. Sorba

For a large class of finite W algebras, the defining relations of a Yangian are proved to be satisfied. Therefore such finite W algebras appear as realisations of Yangians. This result is useful to determine properties of such W algebra representations.

Yu. Malyuta, T. Obikhod

The enhanced gauge groups in F-theory compactified on elliptic Calabi-Yau fourfolds are investigated in terms of toric geometry.

Hiromi Kase, Katsusada Morita, Yoshitaka Okumura

Gauge theories coupled to fermions in generation are reformulated in a modified version of extended differential geometry with the symbol $χ$. After discussing several toy models, we will reformulate in our framework the standard model based on Connes' real structure. It is shown that for the most general bosonic lagrangin which is required to also recon

E. Franco, V. Lubicz

We compute the relation between the quark mass defined in the minimal modified $\MSbar$ scheme and the mass defined in the ``Regularization Invariant" scheme (RI), up to the NNLO order. The RI scheme is conveniently adopted in lattice QCD calculations of the quark mass, since the relevant renormalization constants in this scheme can be evaluated in a non

Jong-Phil Lee, Chun Liu, H. S. Song

The Lambda_b to Lambda_c semileptonic decay is analyzed in the framework of heavy quark effective theory to the order of 1/m_c and 1/m_b. The QCD sum rule and large N_c predictions to the decay form factors are applied. It argues that the subleading baryonic Isgur-Wise function in the large N_c limit vanishes. The decay rates, distributions and asymmetry par

Sarira Sahu, Vishnu M. Bannur

Assuming the violation of equivalence principle (VEP) by ultra high energy AGN neutrinos we study the effect of random magnetic field fluctuation on conversion of electron neutrinos to tau anti-neutrinos.

N. V. Mikheev, G. Raffelt, L. A. Vassilevskaya

Magnetic fields mix axions with photons, allowing for the cyclotron process e -> e + a by virtue of an intermediate plasmon even if axions do not couple to electrons at tree level. The axion and longitudinal-plasmon dispersion relations always cross for a certain wave number, leading to a resonant enhancement of this process. Even then, however, it cannot qu

M. Krawczyk

One very light neutral Higgs scalar with mass, say, below 40-50 GeV is still allowed in the non-supersymmetric 2HDM (Model II), while the remaining particles of the Higgs sector in this model have to be heavier. The possibility of testing such a scenario at Muon Colliders is discussed.

Peter Hasenfratz

This lecture note starts with a pedagogical introduction to the theoretical background and properties of perfect actions, gives some details on topology and instanton solutions and ends with a discussion on the recent developments concerning chiral symmetry.

M. Testa

We show that a modification of the BRST lattice quantization allows to circumvent an old paradox, formulated by Neuberger, related to lattice Gribov copies and non-perturbative BRST invariance. In the continuum limit the usual BRST formulation is recovered.

The Soudan 2 collaboration

We have searched for the proton decay mode proton to neutrino K+ using the one-kiloton Soudan 2 high resolution calorimeter. Contained events obtained from a 3.56 kiloton-year fiducial exposure through June 1997 are examined for occurrence of a visible K+ track which decays at rest into mu+ nu or pi+ pi0. We found one candidate event consistent with backgrou

The WA102 Collaboration, D. Barberis et al

A study has been made of pseudoscalar mesons produced centrally in pp interactions. The results show that the eta and etaprime appear to have a similar production mechanism which differs from that of the pi0. The production properties of the eta and etaprime are not consistent with what is expected from double Pomeron exchange. In addition the production mec

T. Gonzalez, C. Gonzalez, J. Mateos, D. Pardo

Shot-noise suppression is investigated in nondegenerate diffusive conductors by means of an ensemble Monte Carlo simulator. The universal 1/3 suppression value is obtained when transport occurs under elastic collision regime provided the following conditions are satisfied: (i) The applied voltage is much larger than the thermal value; (ii) the length of the

Maksim Skorobogatiy, Hong Guo, Martin Zuckermann

We have investigated the relaxational dynamics for a protein model at various temperatures. Theoretical analysis of this model in conjunction with numerical simulations suggests several relaxation regimes, including a single exponential, a power law and a logarithmic time dependence. Even though a stretched exponential form gives a good fit to the simulation

A. A. Golubov, M. Yu. Kupriyanov

The anomalous proximity effect between a d-wave superconductor and a surface layer with small electronic mean free path is studied theoretically in the framework of the Eilenberger equations. The angular and spatial structure of the pair potential and the quasiclassical propagators in the interface region is calculated selfconsistently. The variation of the

Sorin Solomon

We give a microscopic representation of the stock-market in which the microscopic agents are the individual traders and their capital. Their basic dynamics consists in the auto-catalysis of the individual capital and in the global competition/cooperation between the agents mediated by the total wealth invested in the stock (which we identify with the stock-i

H. Diamant, D. Andelman

We review a new theoretical approach to the kinetics of surfactant adsorption at fluid-fluid interfaces. It yields a more complete description of the kinetics both in the aqueous solution and at the interface, deriving all equations from a free-energy functional. It also provides a general method to calculate dynamic surface tensions. For non-ionic surfactan

D. N. Aristov

We analyze the asymptotic behavior of the exponential form in the fermionic density operators as the function of ruling parameter Q. In the particular case Q=πthis exponential associates with the Wigner-Jordan transformation for XY spin chain model. We compare the bosonization approach and the evaluation via the Toeplitz determinant. The use of Szego-Kac the

Alexei K. Kolezhuk

We present the class of models of a nonmagnetic impurity in S=1/2 generalized ladder with an AKLT-type valence bond ground state, and of a S=1/2 impurity in the S=1 AKLT chain. The ground state in presence of impurity can be found exactly. Recently studied phenomenon of local enhancement of antiferromagnetic correlations around the impurity is absent for thi

P. -B. Gossiaux, Z. Pluhar, H. A. Weidenmueller

Using the Landauer formula and a random matrix model, we investigate the autocorrelation function of the conductance versus magnetic field strength for ballistic electron transport through few-channel microstructures with the shape of a classically chaotic billiard coupled to ideal leads. This function depends on the total number M of channels and the parame

Emil Polturak, Gad Koren, David Cohen, Ofer Nesher

We report measurements of the critical temperature of YBCO-Co doped YBCO Superconductor-Normal bilayer films. Depending on the morphology of the S-N interface, the coupling between S and N layers can be turned on to depress the critical temperature of S by tens of degrees, or turned down so the layers appear almost totally decoupled. This novel effect can be

Giulio Casati, Tomaz Prosen

We study the quantum behaviour of chaotic billiards which exhibit classically diffusive behaviour. In particular we consider the stadium billiard and discuss how the interplay between quantum localization and the rich structure of the classical phase space influences the quantum dynamics. The analysis of this model leads to new insight in the understanding o

Tomaz Prosen

Dynamical Lie-algebraic method for the construction of local quantum invariants of motion in non-integrable many-body systems is proposed and applied to a simple but generic toy model, namely an infinite kicked $t-V$ chain of spinless fermions. Transition from integrable via {pseudo-integrable (\em intermediate}) to quantum ergodic (quantum mixing) regime in

A. I. Sokolov, E. V. Orlov, V. A. Ul'kov

The renormalization group approach in three dimensions is used to estimate the universal critical value g_6^* of the dimensionless sextic effective coupling constant for the Ising model. The four-loop RG expansion for g_6 is calculated and resummed by means of the Pade-Borel and Pade-Borel-Leroy procedures resulting in g_6^* = 1.596, while the most accurate

Xiashoa Wang, Qiming Li, C. M. Soukoulis

We investigate the scaling properties of zero temperature conductances at integer quantum Hall plateau transitions in the lowest Landau band of a two-dimensional tight-binding model. Scaling is obeyed for all energy and system sizes with critical exponent nu =7/3 . The arithmetic average of the conductance at the localization-delocalization critical point is

T. H. Baker, P. J. Forrester, P. A. Pearce

Recent theoretical studies of chaotic scattering have encounted ensembles of random matrices in which the eigenvalue probability density function contains a one-body factor with an exponent proportional to the number of eigenvalues. Two such ensembles have been encounted: an ensemble of unitary matrices specified by the so-called Poisson kernel, and the Lagu

L. Biferale, D. Pierotti, F. Toschi

Helicity transfer in a shell model of turbulence is investigated. In particular, we study the scaling behavior of helicity transfer in a dynamical model of turbulence lacking inversion symmetry. We present some phenomenological and numerical support to the idea that Helicity becomes -at scale small enough- a passively-advected quantity.

Alan Stockton, Gabriela Canalizo, Laird M. Close

We present the results of adaptive-optics imaging of the z=0.2923 QSO PG 1700+518 in the J and H bands. The extension to the north of the QSO is clearly seen to be a discrete companion with a well-defined tidal tail, rather than a feature associated with the host galaxy of PG 1700+518 itself. On the other hand, an extension to the southwest of the QSO (seen

Y. K. Ng

A quantitative method is presented to compare observed and synthetic colour-magnitude diagrams (CMDs). The method is based on a chi^2 merit function for a point (c_i,m_i) in the observed CMD, which has a corresponding point in the simulated CMD within n*sigma(c_i,m_i) of the error ellipse. The chi^2 merit function is then combined with the Poisson merit func

Edwin A. Bergin, Gary J. Melnick, David A. Neufeld

We have used a coupled time-dependent chemical and dynamical model to investigate the lifetime of the chemical legacy left in the wake of C-type shocks. We concentrate this study on the chemistry of H2O and O2, two molecules which are predicted to have abundances that are significantly affected in shock-heated gas. Two models are presented: (1) a three-stage

R. Schopper, H. Lesch, G. T. Birk

Magnetic field-aligned electric fields are characteristic features of magnetic reconnection processes operating in externally agitated magnetized plasmas. An especially interesting environment for such a process are the coronae of accretion disks in active galactic nuclei (AGN). There, Keplerian shear flows perturb the quite strong disk magnetic field leadin

N. A. Arkhipova, V. N. Lukash, E. V. Mikheeva

We present an analysis of cosmological models with mixed dark matter (spectrum slope of density perturbations $n_S \in [0.6, 1.6]$, hot dark matter abundance $Ω_ν\in [0.0, 0.6]$) in spatially flat Universe, based on Press-Schechter formalism (P\&S). We found that the models with $n_S > 1$ and $Ω_ν< 0.5$ are preferable. Additionally, for all considered models

T. M. Brown, H. C. Ferguson, S. A. Stanford, J. -M. Deharveng

We present Faint Object Camera (FOC) ultraviolet images of the central 14x14&#39;&#39; of Messier 31 and Messier 32. The hot stellar population detected in the composite UV spectra of these nearby galaxies is partially resolved into individual stars, and their individual colors and apparent magnitudes are measured. We detect 433 stars in M 31 and 138 stars i

L. Greggio, M. Tosi, M. Clampin, G. De Marchi

We present WFPC2-HST photometry (in the F439W and F555W bands) of the resolved stars in NGC 1569. The derived color-magnitude diagram (CMD) contains 2800 objects down to the 26th mag, and is complete down to the 23rd. Adopting the literature distance modulus and reddening, the CMD samples stars more massive than 4 Mo, corresponding to a look-back time of 0.1

H. Boehringer, Y. Tanaka, R. F. Mushotzky, Y. Ikebe

We present the results of a combined study of ASCA and ROSAT observations of the distant cluster Abell 2390.We determine the surface brightness profile and the gas density distribution of the cluster from the ROSAT PSPC and HRI data. A combined spatially resolved spectral analysis of the ASCA and ROSAT data show that the temperature distribution of the intra

Francisco J. Castander, D. Q. Lamb

The IRAS 100 micron image of the GRB 970228 field shows that the amount of galactic dust in this direction is substantial and varies on arcminute angular scales. From an analysis of the observed surface density of galaxies in the $2.6&#39; \times 2.6&#39;$ HST WFPC image of the GRB 970228 field, we find $A_V = 1.1 \pm 0.10$. From an analysis of the observed

Carlo Graziani, Donald Q. Lamb, Jean M. Quashnock

BATSE, Ulysses, and TGRS and KONUS on WIND detected four gamma-ray events within 1.8 days during 1996 October 27-29, consistent with coming from the same location on the sky. We assess the evidence that these events may be due to a series of bursts from a single source by calculating the probability that such a clustering in position and in time of occurrenc

Benjamin D. Wandelt, Eric Hivon, Kris M. Gorski

We report the development of numerical tools for the topological analysis of sub--degree resolution, all--sky maps. Software to be released in the HEALFAST (V0.9) package defines neighbour relationships for the HEALPIX tessellation of the sphere. We apply this routine to a fast extrema search which scales strictly linearly in the number of pixels, $N_{p}$. W

Bozhidar Z. Iliev

We propose a new systematic fibre bundle formulation of nonrelativistic quantum mechanics. The new form of the theory is equivalent to the usual one but it is in harmony with the modern trends in theoretical physics and potentially admits new generalizations in different directions. In it a pure state of some quantum system is described by a state section (a

Bozhidar Z. Iliev

We propose a version of the non-relativistic quantum mechanics in which the pure states of a quantum system are described as sections of a Hilbert (generally infinitely-dimensional) fibre bundle over the space-time. There evolution is governed via (a kind of) a parallel transport in this bundle. Some problems concerning observables are considered. There are

A. K. Pati, S. V. Lawande

We show that the quadratic short time behaviour of transition probability is a natural consequence of the inner product of the Hilbert space of the quantum system. We prove that Schrödinger time evolution between two successive measurements is not a necessary but only a sufficient condition for predicting quantum Zeno effect. We provide a relation between th

M. Revzen, A. Mann

The temperature dependence of the Casimir effect for the radiation field confined between two conducting plates is analysed. The Casimir energy is shown to decline exponentially with temperature while the Casimir entropy which is defined in the text is shown to approach a limit which depends only on the geometry of the constraining plates. The results are di

J. Reinhold, J. Friese, H. -J. Koerner, R. Schneider

We have measured production yields and longitudinal momentum distributions of projectile-like fragments in the reaction 129Xe + 27Al at an energy of Elab=790 AMeV. Production cross sections higher than expected from systematics were observed for nuclei in the neutron-deficient tails of the isotopic distributions. A comparison with previously measured data fr

Hiromichi Takagi

In this paper, I review the section 8 of V.V.Shokurov&#39;s paper &#39;3-fold log flips&#39;.

Vik. S. Kulikov

Chisini&#39;s conjecture asserts that for a cuspidal curve $B\subset \mathbb P^2$ a generic morphism $f$ of a smooth projective surface onto $\mathbb P^2$ of degree $\geq 5$, branched along $B$, is unique up to isomorphism. We prove that if $°f$ is greater than the value of some function depending on the degree, genus, and number of cusps of $B$, then the Ch

Vik. S. Kulikov

We prove the equivalence of the Jacobian Conjecture (JC(n)) and the Conjecture on the cardinality of the set of fixed points of a polynomial nilpotent mapping (JN(n)) and prove a series of assertions confirming JN(n).

N. E. Mavromatos

In this talk I give a preliminary account of original results, obtained in collaboration with John Ellis. Details and further elaboration will be presented in a forthcoming publication. We present a proposal for a non-critical (Liouville) string approach to confinement of four-dimensional (non-abelian) gauge theories, based on recent developments on the subj

S. N. Gninenko

If the magnetic moment of unstable tau neutrinos with the mass of $O$(MeV) is in the region of $10^{-8}μ_{B} \lesssim μ_{ν_τ} \lesssim 10^{-6}μ_{B}$, it is compatible with the present experimental and cosmological bounds. It is pointed out here, that if the tau neutrino has such a large magnetic moment and can oscillate into a neutrino of another flavour the

E. Krotscheck, J. Paaso, M. Saarela, K. Schoerkhuber

We calculate microscopically the properties of the dilute He-3 component in a He-3/--He-4 mixture. These depend on both, the dominant interaction between the impurity atom and the background, and the Fermi liquid contribution due to the interaction between the constituents of the He-3 component. We first calculate the dynamic structure function of a He-3 imp

Yukio Tanaka, Satoshi Kashiwaya

In order to examine the influences of the spatial dependence of the pair potential, the d.c. Josephson current in d-wave superconductors is calculated using self-consistently determined pair potentials. The results show that the suppression of the d-wave pair potential near the insulator does not have serious effect on the properties of the Josephson current

Ofer Biham, Ofer Malcai, Moshe Levy, Sorin Solomon

The dynamics of generic stochastic Lotka-Volterra (discrete logistic) systems of the form \cite{Solomon96a} $w_i (t+1) = λ(t) w_i (t) + a {\bar w (t)} - b w_i (t) {\bar w(t)}$ is studied by computer simulations. The variables $w_i$, $i=1,...N$, are the individual system components and ${\bar w (t)} = {1\over N} \sum_i w_i (t)$ is their average. The parameter

Shoichi Ichinose, Noriaki Ikeda

We present some approaches to the perturbative analysis of the classical and quantum gravity. First we introduce a graphical representation for a global SO(n) tensor $(\pl)^d h_\ab$, which generally appears in the weak field expansion around the flat space: $g_\mn=\del_\mn+h_\mn$. Making use of this representation, we explain 1) Generating function of graphs

K. Zarembo

Renormalization group transformations for Schrödinger equation are performed in $ϕ^4$ and in Yang-Mills theories. The dependence of the ground state wave functional on rapidly oscillating fields is found. For Yang-Mills theory, this dependence restricts a possible form of variational ansatz compatible with asymptotic freedom.

Tatsushi Suginohara, Jeremiah P. Ostriker

We use high-resolution hydrodynamic simulations to investigate the density profile of hot gas in clusters of galaxies, adopting a variant of cold dark matter cosmologies and employing a cosmological N-body/smoothed particle hydrodynamics code to follow the evolution of dark matter and gas. In addition to gravitational interactions, gas pressure, and shock he

R Benton Metcalf

The dispersion in the peak luminosities of high redshift type Ia supernovae will change with redshift due to gravitational lensing. This lensing is investigated with an emphasis on the prospects of measuring it and separating it from other possible sources of redshift dependent dispersion. Measuring the lensing induced dispersion would directly constrain the

R. Jagannathan

The traditional approach to accelerator optics, based mainly on classical mechanics, is working excellently from the practical point of view. However, from the point of view of curiosity, as well as with a view to explore quantitatively the consequences of possible small quantum corrections to the classical theory, a quantum mechanical formalism of accelerat

R. Jagannathan

It is suggested that the (p,q)-hypergeometric series studied by Burban and Klimyk (in Integral Transforms and Special Functions, 2 (1994) 15 - 36) can be considered as a special case of a more general (P,Q)-hypergeometric series.

C. M. Hull, B. Julia

We consider the dimensional reduction/compactification of supergravity, string and M-theories on tori with one time-like circle. We find the coset spaces in which the massless scalars take their values, and identify the discrete duality groups.

Jae Hyung Yee

We explain how static multi-vortex solutions arise in non-linear field theories, by taking the non-linear Schrödinger equation coupled to Chern-Simons field (Jackiw-Pi model) and a fermion Chern-Simons theory as simple examples. We then construct a fermion Maxwell-Chern-Simons theory which has consistent static field equations, and show that it has the same

L. D. Soloviev

We consider a relativistic quantum model of confined massive spinning quarks and antiquarks which describes leading Regge trajectories of mesons. The quarks are described by the Dirac equations and the gluon contribution is approximated by the Nambu-Goto straight-line string. The string tension and the current quark masses are the main parameters of the mode

Andre de Gouvea, Alexander Friedland, Hitoshi Murayama

Most of the phenomenological studies of supersymmetry have been carried out using the so-called minimal supergravity scenario, where one assumes a universal scalar mass, gaugino mass, and trilinear coupling at M_{GUT}. Even though this is a useful simplifying assumption for phenomenological analyses, it is rather too restrictive to accommodate a large variet

J. G. Smith

There has been much progress in measurements of charmless hadronic B decays during 1997. Building on the previous indications from CLEO and LEP, CLEO now has clear signals in five exclusive final states: K^+π^, K^0π^+, etapr K^+, etapr K^0, and omega K^+. The branching fractions for the etapr K modes are several times larger than the others. A similar striki

B. Gerlach, J. Wuesthoff, M. O. Dzero, M. A. Smondyrev

We consider a model describing the one-dimensional confinement of an exciton in a symmetrical, rectangular quantum-well structure and derive upper and lower bounds for the binding energy $E_b$ of the exciton. Based on these bounds, we study the dependence of $E_b$ on the width of the confining potential with a higher accuracy than previous reports. For an in

A. I. Sokolov, V. A. Ul&#39;kov, E. V. Orlov

Higher-order vertices at zero external momenta for the scalar field theory describing the critical behaviour of the Ising model are studied within the field-theoretical renormalization group (RG) approach in three dimensions. Dimensionless six-point g_6 and eight-point g_8 effective coupling constants are calculated in the three-loop approximation. Their num

A. B. Kuklov

Low energy collective mode of a confined Bose-Einstein condensate should demonstrate the echo effect in the regime of Landau damping. This echo is a signature of reversible nature of Landau damping. General expression for the echo profile is derived in the limit of small amplitudes of the external pulses. Several universal features of the echo are found. The

Yong Baek Kim, Pinaki Majumdar, A. J. Millis, Boris I. Shraiman

We investigate the possible origin of anomalous Hall effect in the CMR (colossal magnetoresistance) materials - the doped rare earth manganites - observed recently by Matl et al. It is demonstrated that the spin-orbit interaction in the double exchange model couples magnetization to the Berry phase associated with three dimensional spin textures and induces

Masashi Yamashiro, Yukio Tanaka, Satoshi Kashiwaya

To clarify the origin of anomalous behaviors in Pb/Sr2RuO4/Pb junctions in terms of the pairing symmetry, a theory of the d.c. Josephson current in s-wave superconductor / p-wave superconductor / s-wave superconductor junctions is developed. Calculated results on the temperature dependence of the critical Josephson current exhibit non-monotonous behaviors wh

M. Skorobogatiy, G. Tiana

In this work we have studied, with the help of a simple on-lattice model, the distribution pattern of sites sensitive to point mutations (&#39;hot&#39; sites) in protein-like chains. It has been found that this pattern depends on the regularity of the matrix that rules the interaction between different kinds of residues. If the interaction matrix is dominate

Michael L. Allen, Philipp P. Kronberg

We have determined detailed radio spectra for 26 compact sources in the starburst nucleus of M82, between 74 and 1.3 cm. Seventeen show low-frequency turnovers. One other has a thermal emission spectrum, and we identify it as an HII region. The low frequency turnovers are due to absorption by the interstellar gas in M82. New information on the AGN candidate

L. Perivolaropoulos, N. Simatos

We apply new statistical tests on the four year 53 GHz DMR data and show that there is significant probability for the existence of coherent temperature discontinuities hidden in the CMB maps around the Galactic Poles. Comparing Monte Carlo simulations with the DMR maps we find that the probability for the existence of a coherent discontinuity with amplitude

T. Miyaji, Y. Ishisaki, Y. Ogasaka, Y. Ueda

We have made a series of joint spectral fits for two blank fields, the Lockman Hole and the Lynx-3A field, where a significant amount of both ASCA and ROSAT PSPC data exist after thorough screenings. The ASCA SIS, GIS and ROSAT PSPC spectra from these fields have been fitted simultaneously. Comparison at E>1$keV shows general agreement within 10% in the Lock

Andre Lukas, Burt A. Ovrut, K. S. Stelle, Daniel Waldram

It is shown that the effective five-dimensional theory of the strongly coupled heterotic string is a gauged version of N=1 five-dimensional supergravity with four-dimensional boundaries. For the universal supermultiplets, this theory is explicitly constructed by a generalized dimensional reduction procedure on a Calabi-Yau manifold. A crucial ingredient in t

Kazusumi Ino

We study pairing effects in the edge states of paired fractional quantum Hall states by using persistent edge currents as a probe. We give the grand partition functions for edge excitations of paired states (Pfaffian, Haldane-Rezayi, 331) coupling to an Aharanov-Bohm flux and derive the exact formulas of the persistent edge current. We show that the currents

Mark Trodden

Contrary to naive cosmological expectations, all evidence suggests that the universe contains an abundance of matter over antimatter. This article reviews the currently popular scenario in which testable physics, present in the standard model of electroweak interactions and its modest extensions, is responsible for this fundamental cosmological datum. A peda

Ramzi R. Khuri

Quantum aspects of black holes represent an important testing ground for a theory of quantum gravity. The recent success of string theory in reproducing the Bekenstein-Hawking black hole entropy formula provides a link between general relativity and quantum mechanics via thermodynamics and statistical mechanics. Here we speculate on the existence of new and

Marco Billo, Frederik Denef, Pietro Fre, Igor Pesando

The limiting procedure of special Kahler manifolds to their rigid limit is studied for moduli spaces of Calabi-Yau manifolds in the neighbourhood of certain singularities. In two examples we consider all the periods in and around the rigid limit, identifying the nontrivial ones in the limit as periods of a meromorphic form on the relevant Riemann surfaces. W

S. Brattke, U. Kallmann, W. -D. Hartmann

The coherent dark resonance between the hyperfine levels F=1, m=0 and F=2, m=0 of the rubidium ground state has been observed experimentally with the light of a pulsed mode-locked diode laser operating at the D1 transition frequency. The resonance occurs whenever the pulse repetition frequency matches an integer fraction of the rubidium 87 ground state hyper

S. A. Abel, B. C. Allanach

We analyse the mass spectrum of the Constrained Minimal Supersymmetric Standard Model at the low tan beta fixed point. We find that the model only satisfies experimental and dark matter bounds in regions where the vacuum is meta-stable -- ie where it violates `unbounded from below&#39; (UFB) bounds. Adding a small amount of R-parity violation solves these pr

Andreas Karch, Dieter Lust, Douglas J. Smith

We present an explicit relation between the Hanany-Witten and Geometric Engineering approaches of realising gauge theories in string theory. The last piece in the puzzle is a T-duality relating arbitrary Hanany-Witten setups and fractional branes.

P. Marronetti, G. J. Mathews, J. R. Wilson

We report on the first calculations of fully relativistic binary circular orbits to span a range of separation distances from the innermost stable circular orbit (ISCO), deeply inside the strong field regime, to a distance ($\sim$ 200 km) where the system is accurately described by Newtonian dynamics. We consider a binary system composed of two identical cor

I. V. Gaidaenko, A. V. Novikov, V. A. Novikov, A. N. Rozanov

Large top quark mass is responsible for the enhancement of the oblique radiative corrections in SUSY models. We present the analytical formulas for these corrections to the $W$-boson mass $m_W$ and to $Z$ $l^+ l^-$ coupling constants. The comparison with the result of the Standard Model fit is made.

Florin P. Boca

For each $α\in (0,1)$, $A_α$ denotes the universal $C^*$-algebra generated by two unitaries $u$ and $v$, which satisfy the commutation relation $uv=\exp (2πiα)vu$. We consider the order four automorphism $σ$ of $A_α$ defined by $σ(u)=v$, $σ(v)=u^{-1}$ and describe a method for constructing projections in the fixed point algebra $A_α^σ$, using Rieffel&#39;s i

R. Arvieu, P. Rozmej

We analyze the time evolution of simple nuclear rotational wave packets (WP) called circular, linear or elliptic, depending on squeezing parameter $η$, assuming that $E=\hbarω_0 I(I+1)$. The scenario of fractional revivals found by Averbukh and Perelman is adapted to symmetric WP and compared to that which holds for asymmetric WP. In both cases various shape

S. Catani, M. Fontannaz, E. Pilon

We study the production of isolated photons in $e^+e^-$ annihilation and give the proof of the all-order factorization of the collinear singularities. These singularities are absorbed in the standard fragmentation functions of partons into a photon, while the effects of the isolation are consistently included in the short-distance cross section. We compute t

J. M. Martinez Resco, M. A. Valle Basagoiti

The speed of cool pions in the chiral limit is analytically computed at low temperature within the imaginary time formalism to two loop order. This evaluation shows a logarithmic dependence in the temperature where the scale within the logarithm is very large compared to the pion decay constant.