March 1997 arXiv papers — page 9

Alejandro Gonzalez

We show that the primordial density field imposes certain degree of coherence in the orientation of density perturbations. We quantify the scale of coherence and show that is significant on scales of at least $30-40h^{-1}$Mpc, being more important in density fields with flat spectrum. Evidence is also presented that the reason for this coherence is that the

Robert Gassler

We introduce mixed Segre numbers of ideals which generalize the notion of mixed multiplicities of ideals of finite colength and show how many results on mixed multiplicities can be extended to results on mixed Segre numbers. In particular, we give a necessary and sufficient condition in terms of these numbers for two ideals to have the same integral closure.

J. W. Moffat

A stochastic theory of gravity is described in which the metric tensor is a random variable such that the spacetime manifold is a fluctuating physical system at a certain length scale. A general formalism is described for calculating probability densities for gravitational phenomena in a generalization of general relativity (GR), which reduces to classical G

B. D. Keister

Sum rules based upon heavy quark effective theory indicate that the Isgur-Wise function $ξ(w)$ has a minimum slope as w approaches 1, which is zero for light degrees of freedom with zero spin and 1/4 for light spin 1/2. Quark-model studies reveal sources for a minimum slope from a variety of relativistic effects. In this paper the origins of the minimum slop

Antonio C. C. Guimaraes, George E. A. Matsas, Daniel A. T. Vanzella

We discuss the influence of the background thermal bath on the depolarization of electrons in high-energy storage rings, and on the photon emission associated with the spin flip. We focus, in particular, on electrons at LEP. We show that in a certain interval of solid angles the photon emission is enhanced several orders of magnitude because of the presence

R. V. Gavai, Sourendu Gupta

We re-analyse the data on J/psi cross sections for proton-nucleus and nucleus-nucleus collisions obtained by the CERN experiments NA38, NA51 and NA50. Our systematic analysis of error propagation shows that the no anomalous suppression of J/psi in Pb-Pb collisions can be substantiated at 95% confidence limit. The significance of the NA50 result would be enha

T. Gonzalez, O. M. Bulashenko, J. Mateos, D. Pardo

We present a Monte Carlo analysis of shot-noise suppression due to long-range Coulomb interaction in semiconductor samples under a crossover between diffusive and ballistic transport regimes. By varying the mean time between collisions we find that the strong suppression observed under the ballistic regime persists under quasi-ballistic conditions, before be

Mina Teicher

In this paper we introduce a formula to compute Chern classes of fibered products of algebraic surfaces. For f, a generic projection to CP^2, of an algebraic surface X, we define X_k (for k smaller than degf) to be the k products of X over f minus the big diagonal. For k=degf, X_k is called the Galois cover of f w.r.t. full symmetric group. Let S be the bran

N. Akchurin, S. V. Goloskokov, O. V. Selyugin

Spin-dependent pomeron effects are analyzed for elastic $pp$ scattering and calculations for spin-dependent differential cross sections, analyzing power and double-spin correlation parameters are carried out for the energy range of the Relativistic Heavy Ion Collider (RHIC) at BNL. In this energy range, $50 \leq \sqrt{s} \leq 500 \gev$, the structure of pome

Zhi-zhong Xing

By use of the one-loop renormalization group equations and current experimental data, we study the off-diagonal asymmetries of the Cabibbo-Kobayashi-Maskawa (CKM) matrix at the GUT scale in the framework of the standard model as well as its two Higgs and supersymmetric extensions. It is concluded that the possibility of a symmetric CKM matrix at the GUT scal

Werner Bernreuther, Arnd Brandenburg, Peter Uwer

We calculate the cross section for $e^+ e^-$ annihilation into three jets for massive quarks at next-to-leading order in perturbative QCD, both on and off the $Z$ resonance. Our computation allows the implementation of any jet clustering algorithm. We give results for the three-jet cross section involving $b$ quarks for the JADE and Durham algorithm at c.m.

M. Baig, D. Espriu, D. Johnston, R. P. K. C. Malmini

For the 3D gonihedric Ising models defined by Savvidy and Wegner the bare string tension is zero and the energy of a spin interface depends only on the number of bends and self-intersections, in antithesis to the standard nearest-neighbour 3D Ising action. When the parameter kappa weighting the self-intersections is small the model has a first order transiti

R. Radhakrishnan, M. Lakshmanan, J. Hietarinta

By constructing the general six-parameter bright two-soliton solution of the integrable coupled nonlinear Schrodinger equation (Manakov model) using the Hirota method, we find that the solitons exhibit certain novel inelastic collision properties, which have not been observed in any other (1+1) dimensional soliton system so far. In particular, we identify th

I. Brevik, A. A. Bytsenko, H. B. Nielsen

The thermodynamic free energy F is calculated for a gas whose particles are the quantum excitations of a piecewise uniform bosonic string. The string consists of two parts of length L_I and L_II, endowed with different tensions and mass densities, adjusted in such a way that the velocity of sound always equals the velocity of light. The explicit calculation

Alexander A. Chernitskii

A direct method for obtaining the differential conservation laws in the field theory from the principle of stationary action is proposed. The method is based on a variation of field functions through small local transformation of a special kind. The action of general theory of relativity are considered.

Tohru Eguchi, Kentaro Hori, Chuan-Sheng Xiong

We propose that the Virasoro algebra controls quantum cohomologies of general Fano manifolds $M$ ($c_1(M)>0$) and determines their partition functions at all genera. We construct Virasoro operators in the case of complex projective spaces and show that they reproduce the results of Kontsevich-Manin, Getzler etc. on the genus-0,1 instanton numbers. We also co

Robert Konik, Andre' LeClair

We define an infinite class of integrable theories with a defect which are formulated as chiral defect perturbations of a conformal field theory. Such theories can be interacting in the bulk, and are purely transmitting through the defect. The examples of the sine-Gordon theory and Ising model are worked out in some detail.

Andrew N. W. Hone

Scaling similarity solutions of three integrable PDEs, namely the Sawada-Kotera, fifth order KdV and Kaup-Kupershmidt equations, are considered. It is shown that the resulting ODEs may be written as non-autonomous Hamiltonian equations, which are time-dependent generalizations of the well-known integrable Hénon-Heiles systems. The (time-dependent) Hamiltonia

V. I. Man'ko, G. Marmo, F. Zaccaria

The q-deformation of harmonic oscillators is shown to lead to q-nonlinear vibrations. The examples of q-nonlinearized wave equation and Schrödinger equation are considered. The procedure is generalized to broader class of nonlinearities related to other types of deformations. The nonlinear noncanonical transforms used in the deformation procedure are shown t

Xinwei Kong, Finn Ravndal

The lowest radiative correction to the Casimir energy density between two parallel plates is calculated using effective field theory. Since the correlators of the electromagnetic field diverge near the plates, the regularized energy density is also divergent. However, the regularized integral of the energy density is finite and varies with the plate separati

Lev Vaidman

Cohen and Hiley [Phys. Rev. A 52, 76 (1995)] have criticized the analysis of Hardy's gedanken experiment according to which the contradiction with quantum theory in Hardy's experiment arises due the failure of the "product rule" for the elements of reality of pre- and post-selected systems. It is argued that the criticism of Cohen and Hiley i

Peter Nattermann

Motivated by the problems of interpretation of a nonlinear evolution equation in quantum mechanics we discuss in this contribution the concept of nonlinear gauge transformations, that has recently been introduced in joint work with Doebner and Goldin, in the framework of Mielnik's Generalized Quantum Mechanics. Using these gauge transformations we constr

Siddhartha Sahi

Inhomogeneous analogues of symmetric and nonsymmetric Macdonald polynomials were introduced by F. Knop and the author. In the symmetric case A. Okounkov has recently proved a beautiful expansion formula which can be viewed as a multivariable generalization of the q-binomial theorem. It is becoming clear that many interesting results in the symmetric setting

M. A. Semenov-Tian-Shansky

The key concept discussed in these lectures is the relation between the Hamiltonians of a quantum integrable system and the Casimir elements in the underlying hidden symmetry algebra. (In typical applications the latter is either the universal enveloping algebra of an affine Lie algebra, or its q-deformation.) A similar relation also holds in the classical c

J. F. Cai, S. K. Wang, K. Wu, W. Z. Zhao

We obtain Drinfel'd's realization of quantum affine superalgebra $U_q\hat{(gl(1|1))}$ based on the super version of RS construction method and Gauss decomposition.

Peter Bouwknegt, Kareljan Schoutens

We review several fermionic-type character formulae for the characters of the integrable highest weight modules of sl(n)^ at level l=1, and explain how they arise from a spinon basis for these modules. We also review how the Yangian Y(sl(n)) acts on the integrable (sl(n)^)_1 modules and we decompose the characters with respect to this Y(sl(n)) action.

Luis Gonzalez-Mestres

If textbook Lorentz invariance is actually a property of the equations describing a sector of matter above some critical distance scale, several sectors of matter with different critical speeds in vacuum can coexist and an absolute rest frame (the vacuum rest frame, possibly related to the local rest frame of the expanding Universe) may exist without contrad

Alexey K. Mazur

Conventional molecular dynamics simulations macromolecules require long computational times because the most interesting motions are very slow compared with the fast oscillations of bond lengths and bond angles that limit the integration time step. Simulation of dynamics in the space of internal coordinates, that is with bond lengths, bond angles and torsion

P. Elmfors, A. Fasso, M. Huhtinen, M. Lindroos

Fast wire scanners are today considered as part of standard instrumentation in high energy synchrotrons. The extension of their use to synchrotrons working at lower energies, where Coulomb scattering can be important and the transverse beam size is large, introduces new complications considering beam heating of the wire, composition of the secondary particle

J. Bijtebier

We show that the 3D reductions of the Bethe-Salpeter equation have the same bound state spectrum as the original equation, with the possible exception of some solutions for which the corresponding 3D wave function vanishes. The abnormal solutions of the Bethe-Salpeter equation (corresponding to excitations in the relative time-energy degree of freedom), when

P. Bicudo, J. Ribeiro

We study the N pi N coupling, in the framework of a QCD-inspired confining Nambu-Jona-Lasinio model. A simple relativistic confining and instantaneous quark model is reviewed. The Salpeter equation for the nucleon and the boosted pion is solved. The f [n pi n] and f[n pi Delta] couplings are calculated and they turn out to be reasonably good. The sensibility

J. N. De, S. Das Gupta, S. Shlomo, S. K. Samaddar

In a finite temperature Thomas-Fermi theory with realistic nuclear interactions, we construct caloric curves for finite nuclei enclosed in a sphere of about $4 - 8$ times the normal nuclear volume. The specific heat capacity $C_v$ shows a peaked structure that is possibly indicative of a liquid-gas phase transition in finite nuclear systems.

A. E. L. Dieperink, C. L. Korpa

We investigate the modification of the pion-cloud in the nuclear medium and its effect on the nuclear Drell-Yan process. The pion's in-medium self-energy is calculated in a self-consistent delta-hole model, with particle-hole contribution also included. Both the imaginary and real part of the pion's and delta's self-energy are taken into account

M. Schleif, R. Wünsch, Th. Meissner

We study translational and spin-isospin symmetry restoration for the two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we consider a boosted and rotating hedgehog soliton. Corrected classical meson fields are obtained by minimizing a corrected energy functional which has been derived by semi-classical methods ('variation after pro

N. Willis, Y. Le Bornec, A. Zghiche, C. Wilkin

The cross section and tensor analysing power t_20 of the d\vec{d}->eta 4He reaction have been measured at six c.m. momenta, 10 < p(eta) < 90 MeV/c. The threshold value of t_20 is consistent with 1/\sqrt{2}, which follows from parity conservation and Bose symmetry. The much slower momentum variation observed for the reaction amplitude, as compared to that for

H. Hamidian

We use the Wilson-Fisher $ε$ expansion to study quantum critical behavior in gauged Yukawa matrix field theories with weak quenched disorder. We find that the resulting quantum critical behavior is in the universality class of the pure system. As in the pure system, the phase transition is typically first order, except for a limited range of parameters where

S. Randjbar-Daemi, J. Strathdee

In this letter we show how the covariant anomaly emerges in the overlap scheme. We also prove that the overlap scheme correctly reproduces the anomaly in the flavour currents such as $j^5_μ$ in vector like theories like QCD.

Jens Schnittger

These are notes of a seminar given at the 30th International Symposium on the Theory of Elementary Particles, Berlin-Buckow, August 1996. The material is derived from collaborations with E. Cremmer and J.-L. Gervais, and C. Klimcik, and is partially new. Within the general framework of Poisson-Lie symmetry, we discuss two approaches to the problem of constru

C. R. Hagen

A Galilean Chern-Simons field theory is formulated for the case of two interacting spin-1/2 fields of distinct masses M and M&#39;. A method for the construction of states containing N particles of mass M and N&#39; particles of mass M&#39; is given which is subsequently used to display equivalence to the spin-1/2 Aharonov-Bohm effect in the N = N&#39; =1 se

Devis Iellici, Valter Moretti

The thermal partition functions of photons in any covariant gauge and gravitons in the harmonic gauge, propagating in a Rindler wedge, are computed using a local zeta-function approach. The relation with the surface terms previously obtained by D. Kabat is studied. The results are discussed in relation to the quantum corrections to the black hole entropy.

Bodo Lampe, Andreas Ruffing

The sensititivity of various future polarization experiments to the first moment Delta g of the polarized gluon density is elucidated in detail. It is shown to what extent the first moment can be extracted from the future data as compared to the higher moments. We concentrate on two processes which in the near future will become an important source of inform

A. Barducci, R. Casalbuoni, R. Gatto, M. Modugno

Within the composite operator formalism we derive a formula for the pion decay constant $f_π$, as defined directly from the residue at the pion pole of the meson propagator, rather than from the matrix element of the axial current. The calculation is performed under some simplifying assumptions, and we verify the complete consistency with soft-pion results,

Mauro Anselmino, Alessandro Drago, Francesco Murgia

We study a possible origin of single spin asymmetries in the large $p_T$ inclusive production of hadrons in the scattering of unpolarized protons or leptons on transversely polarized nucleons. Such asymmetry is related to the single-spin asymmetry for the process $\p^\uparrow \to q+X$ or, equivalently, to the off-diagonal matrix element of the quark density

M. Klasen, G. Kramer, B. Pötter

We present a next-to-leading order calculation for the virtual photoproduction of one and two jets in $ep$ collisions. Soft and collinear singularities are extracted using the phase space slicing method. The collinear photon initial state singularity depends logarithmically on the mass of the virtual photon and is absorbed into the virtual photon structure f

T. Ohgaki, T. Takahashi, I. Watanabe

Feasibility of a measurement of the partial decay width of the intermediate-mass Higgs boson into two photons at a photon-photon collider is studied by a simulation. The QCD radiative correction for quark pair background processes is taken into account for the realistic background estimation. It is found that the two-photon decay width can be measured with t

K. S. Babu, Christopher Kolda, John March-Russell, Frank Wilczek

Taking the reported high-Q^2 anomaly at HERA as a signal of new physics, we show that several independent considerations point towards s-channel leptoquark production as the most attractive interpretation. We argue that even this option is highly constrained by flavor-changing processes: the couplings must be accurately diagonal in the quark and lepton mass

Peter N. Meisinger, Michael C. Ogilvie

Confinement may be more easily demonstrated at finite temperature using the Polyakov loop than at zero temperature using the Wilson loop. A natural mechanism for confinement can arise via the coupling of the adjoint Polyakov loop to F_{mu nu}^2. We demonstrate this mechanism with a one-loop calculation of the effective potential for SU(2) gluons in a backgro

Brien C. Nolan

A characterisation of when wave tails are strong is proposed. The existence of a curvature induced tail (i.e. a Green&#39;s function term whose support includes the interior of the light-cone) is commonly understood to cause backscattering of the field governed by the relevant wave equation. Strong tails are characterised as those for which the purely radiat

Toshihiko Masuda

Using the continuous decomposition, we classify strongly free actions of discrete amenable groups on strongly amenable subfactors of type III$_λ, 0 < λ< 1$. Winsløw&#39;s fundamental homomorphism is a complete invariant. This removes the extra assumptions in the classification theorems of Loi and Winsløw and gives a complete classification up to cocycle conj

K. Moloni, M. Friesen, Shi Li, V. Souw

Conductivity measurements reflect vortex solid melting in YBCO films. Field-independent glass exponents nu_g=1.9 and z_g=4.0 describe the transition T_g(H) for 0<H<26 T. At low fields, 3D XY exponents nu_{XY}=0.63 and z_{XY}=1.25 are also observed, with z_{XY} smaller than expected. These compete with glass scaling according to multicritical theory. A predic

V. Yu. Irkhin, M. I. Katsnelson

Formation of magnetically ordered state in the Kondo lattices is treated within the degenerate $s-f$ exchange and Coqblin-Schrieffer models. The Kondo renormalizations of the effective coupling parameter, magnetic moment and spin excitation frequencies are calculated within perturbation theory. The results of one-loop scaling consideration of the magnetic st

Anne van Otterlo, Dmitrii S. Golubev, Andrei D. Zaikin, Gianni Blatter

We derive effective dynamical theories for metals and BCS superconductors, based on the effective action formalism. Both the metallic regime $T\gtrsim T_{C}$ and the superconducting regime $T\ll T_{C}$ are studied in the clean and dirty limit. Furthermore, we consider the effect of particle-hole asymmetry in the band structure. Using gauge invariance, the el

C. M. Varma

Any singular deviation from Landau Fermi-liquid theory appears to lead, for arbitrarily small concentration of impurities coupling to a non-conserved quantity, to a vanishing density of states at the chemical potential and infinite resistivity as temperature approaches zero. Applications to copper-oxide metals including the temperature dependence of the anis

E. V. L. de Mello, J. Ranninger

On the basis of the two-site polaron problem, which we solve by exact diagonalization, we analyse the spectral properties of polaronic systems in view of discerning localized from itinerant polarons and bound polaron pairs from an ensemble of single polarons. The corresponding experimental techniques for that concern photoemission and inverse photoemission s

B. L. Altshuler, A. V. Chubukov, A. Dashevskii, A. M. Finkel&#39;stein

We obtained the analog of the Luttinger relation for a commensurate spin-density-wave state. We show that while the relation between the area of the occupied states and the density of particles gets modified in a simple and predictable way when the system becomes ordered, a perturbative consideration of the Luttinger theorem does not work due to the presence

Arne Brataas, C. Zhang, K. A. Chao

We study light scattering from a periodically modulated two dimensional electron gas in a perpendicular magnetic field. If a subband is partially filled, the imaginary part of the dielectric function as a function of frequency contains additional discontinuities to the case of completely filled subbands. The positions of the discontinuities may be determined

S. Ciuchi, F. de Pasquale, S. Fratini, D. Feinberg

A dynamical mean-field theory of the small polaron problem is presented, which becomes exact in the limit of infinite dimensions. The ground state properties and the one-electron spectral function are obtained for a single electron interacting with Einstein phonons by a mapping of the lattice problem onto a polaronic impurity model. The one-electron propagat

Lian Zheng

We consider the problem of quantum and classical phase transitions in double-layer quantum Hall systems at $ν=1/m$ (m odd integers) from a long-wavelength statistical mechanics viewpoint. We derive an explicit mapping of the long-wavelength Lagrangian of the quantum Hall system into that of a three-dimensional isotropic classical XY model whose coupling cons

F. Zhou, B. Spivak

Hall effect in SN and SNS junctions is considered. It is shown that at small temperature the Hall voltage is significantly suppressed as compared to its normal metal value. The time dependence of the Hall voltage in SNS junctions has a form of narrow pulses with the Josephson frequency.

M. Kolesik, M. A. Novotny, P. A. Rikvold, D. M. Townsley

The magnetization switching dynamics in the kinetic Ising model is projected onto a one-dimensional absorbing Markov chain. The resulting projected dynamics reproduces the direct simulation results with great accuracy. A scheme is proposed to utilize simulation data for small systems to obtain the metastable lifetime for large systems and/or for very weak ma

J. G. E. Harris, N. Argaman, S. J. Allen

In DC transport through mesoscopic S-N-S junctions, it is known that the Josephson coupling decreases exponentially with increasing temperature, but the phase dependence of the conductance persists to much higher temperatures and decreases only as 1/T. It is pointed out here that, despite the fact that such a phase-dependent conductance does bring about an A

J. Kondev

Effective field theories of two-dimensional lattice models of fluctuating loops are constructed by mapping them onto random surfaces whose large scale fluctuations are described by a Liouville field theory. This provides a geometrical view of conformal invariance in two-dimensional critical phenomena and a method for calculating critical properties of loop m

Pascal Vaillant

Dysphasic subjects do not have complete linguistic abilities and only produce a weakly structured, topicalized language. They are offered artificial symbolic languages to help them communicate in a way more adapted to their linguistic abilities. After a structural analysis of a corpus of utterances from children with cerebral palsy, we define a semantic lexi

Daniel Schaerer, Thierry Contini, Daniel Kunth, Georges Meynet

We present spectroscopic observations of the central star clusters in NGC 5253 the aim of which is to search for WC stars. Our observations show the presence of Wolf-Rayet (WR) stars not only of WN but also of WC subtype in two star forming regions corresponding to the maximum optical and UV emission. The massive star population we derive is consistent with

A. Laio, G. Rizzi, A. Tartaglia

In the paper we calculate the frequency shift induced on a photon by the interaction with a low density electronic plasma. The technique is the standard perturbation theory of quantum electrodynamics, taking into account the many body character of the plasma. The shift in non relativistic approximation is shown to be blue. Besides the quantum shift also the

Eric J. Hooper, Chris D. Impey, Craig B. Foltz

A sample of 16 quasars selected from the Large Bright Quasar Survey in the redshift range 0.4 < z < 0.5 has been imaged in the R band with the Planetary Camera on the WFPC2 instrument of the Hubble Space Telescope. The host galaxy magnitudes are mostly similar to or brighter than L*, and the host luminosity is positively correlated with the luminosity of the

Pio Francesco Muciaccia, Paolo Natoli, Nicola Vittorio

We present a fast algorithm for generating full sky, high resolution ($\sim 5&#39;$) simulations of the CMB anisotropy pattern. We also discuss the inverse problem, that of evaluating from such a map the full set of $a_{\ell m}$&#39;s and the spectral coefficients $C_\ell$. We show that using an Equidistant Cylindrical Projection of the sky substantially spe

T. Di Matteo, A. C. Fabian

It has been suggested that the final stages of accretion in present--day giant elliptical galaxies occur in an advection-dominated mode. The poor radiative efficiency of this accretion solution accounts for the fact that massive black holes, which are believed to reside in the centres of these galaxies, do not have the luminosities expected if accretion from

Li-Xin Li

The effect of the global rotation of the universe on the formation of galaxies is investigated. It is found that the global rotation provides a natural origin for the rotation of galaxies, and the morphology of the objects formed from gravitational instability in a rotating and expanding universe depends on the amplitude of the density fluctuation, different

G. Marconi, R. Buonanno, M. Castellani, G. Iannicola

We present V,I deep CCD photometry for three fields of the dwarf galaxy in Sagittarius (Sgr). One of the fields is centered on the globular cluster NGC 6715 (M54), which lies in one of the dense clumps of the Sgr galaxy. Comparing the CMD of Sgr with those of globular clusters which are believed to be kinematically associated with the dwarf galaxy, we conclu

Todd M. Tripp, Limin Lu, Blair D. Savage

We present a high signal-to-noise high resolution spectrum of the radio-quiet QSO HS1700+6416 (z = 2.72). Analysis of the absorption line systems with metals yields the following results. (1) The dense cluster of C IV doublets at 2.432 < z(abs) < 2.441 shows the weak line of one C IV absorber apparently aligned with the strong line of a different C IV double

Abraham Loeb, Andrew Ulmer

We show that the disruption of a star by a 10^6 solar mass black hole in a galactic nucleus could under favorable circumstances produce an optically-thick envelope that radiates with a thermal spectrum at the Eddington limit, 10^{44} erg/s, for tens of years. The low apparent temperature of this envelope, 10^4 K, would be easily detectable in optical surveys

George W. Collins, II

The traditional argument to justify Omega_0 = rho/rho_{crit} = 1 which suggests an absurdly close agreement between the initial expansion energy of the universe and its binding energy is reversed to show that it is unreasonable to expect the current value of W to be within a factor of ten or more of unity. The Uncertainty Principle is applied to the initial

Misha Verbitsky

We give a number of equivalent definitions of hypercomplex varieties and construct a twistor space for a hypercomplex variety. We prove that our definition of a hypercomplex variety (used, e. g., in alg-geom/9612013) is equivalent to a definition proposed by Deligne and Simpson, who used twistor spaces. This gives a way to define hypercomplex spaces (to allo

Veniamin Berezinsky, Xavier Martin, and Alexander Vilenkin

Monopole-antimonopole pairs connected by strings and monopole-string networks with $N>2$ strings attached to each monopole can be formed at phase transitions in the early universe. In such hybrid defects, monopoles accelerate under the string tension and can reach ultrarelativistic Lorentz factors, $γ\gg 1$. We study the radiation of gauge quanta by accelera

Benjamin Grinstein, Ira Z. Rothstein

The effective Lagrangian and power counting rules for non-relativistic gauge theories are derived via an expansion in $1/c$. It is shown that the $1/c$ expansion leads to an effective field theory which incorporates a multipole expansion. Failure to use this expansion in the low energy theory leads to a loss of predictive power as the matching procedure beco

J. M. Aroca, H. Fort, R. Gambini

A gauge invariant Hamiltonian representation for SU(2) in terms of a spin network basis is introduced. The vectors of the spin network basis are independent and the electric part of the Hamiltonian is diagonal in this representation. The corresponding path integral for SU(2) lattice gauge theory is expressed as a sum over colored surfaces, i.e. only involvin

James A. Feigenbaum, Peter G. O. Freund, Mircea Pigli

High energy hadronic total cross-section data are found to agree with the predictions of a QCD-string picture.

P. Hajicek

A symmetry based quantization method of reparametrization invariant systems is described; it will work for all systems that possess complete sets of perennials whose Lie algebras close and which generate a sufficiently large symmetry groups. The construction leads to a quantum theory including a Hilbert space, a complete system of operator observables and a

Felix Finster

Local gauge freedom in relativistic quantum mechanics is derived from a measurement principle for space and time. For the Dirac equation, one obtains local U(2,2) gauge transformations acting on the spinor index of the wave functions. This local U(2,2) symmetry allows a unified description of electrodynamics and general relativity as a classical gauge theory

T. Gonzalez, O. M. Bulashenko, J. Mateos, D. Pardo

We present a microscopic analysis of shot-noise suppression due to long-range Coulomb interaction in semiconductor devices under ballistic transport conditions. An ensemble Monte Carlo simulator self-consistently coupled with a Poisson solver is used for the calculations. A wide range of injection-rate densities leading to different degrees of suppression is

B. Craps, F. Roose, W. Troost, A. Van Proeyen

The scalars in vector multiplets of N=2 supersymmetric theories in 4 dimensions exhibit `special Kaehler geometry&#39;, related to duality symmetries, due to their coupling to the vectors. In the literature there is some confusion on the definition of special geometry. We show equivalences of some definitions and give examples which show that earlier definit

B. C. Allanach, S. F. King

The minimal supersymmetric standard model (MSSM), is perhaps the leading candidate for new physics beyond the standard model, but it encounters difficulties with string gauge unification and in addition does not shed any light on the question of fermion masses. We consider a scenario in which the MSSM is valid up to an energy scale of 10^16 GeV, but that abo

Anatoly Golub, Baruch Horovitz

We study a flux lattice which is parallel to superconducting layers, allowing for dislocations and for disorder of both short wavelength and long wavelength. We find that the long wavelength disorder has a significant effect on the phase diagram -- it produces a first order transition within the Bragg glass phase and leads to melting at strong disorder. This

Carlos Barcelo, Luis J. Garay

We study the effects of asymptotically anti-de Sitter wormholes in low-energy field theory and give a general prescription for obtaining the local effective interaction terms induced by them. The choice of vacuum for the matter fields selects a basis of the Hilbert space of anti-de Sitter wormholes whose elements can be interpreted as states containing a giv

Tamiaki Yoneya

We show that the path-integral quantization of relativistic strings with the Schild action is essentially equivalent to the usual Polyakov quantization at critical space-time dimensions. We then present an interpretation of the Schild action which points towards a derivation of superstring theory as a theory of quantized space-time where the squared string s

M. Fabrizio, R. Mélin

We analyze by means of real space Renormalization Group (RG) as well as by exact diagonalizations the properties of a single-chain model of a doped spin-Peierls system, where a major role is played by the localized moments created by the impurities. We are able to follow analytically the RG flow, which allows us to determine the relevant cross-over temperatu

Debades Bandyopadhyay, Somenath Chakrabarty, Subrata Pal

We investigate the influence of a strong magnetic field on various properties of neutron stars with quark-hadron phase transition. The one-gluon exchange contribution in a magnetic field is calculated in a relativistic Dirac-Hartree-Fock approach. In a magnetic field of $5\times 10^{18}$G in the center of the star, the overall equation of state is softer in

The WA89 Collaboration, M. I. Adamovich

Inclusive cross sections for Xi^- hyperon production in high-energy Sigma^-, pi^- and neutron induced interactions were measured by the experiment WA89 at CERN. Secondary Sigma^- and pi^- beams with average momenta of 345 GeV/c and a neutron beam of average momentum 65 GeV/c were produced by primary protons of 450 GeV/c from the CERN SPS. Both single and dou

Yosuke Imamura

We present a solution of M(atrix) theory describing type IIA fundamental string. Our construction is based on the central charge of the longitudinal membrane (= fundamental string), the BPS saturation condition and the relation between M(atrix) theory and supersymmetric Yang-Mills theory. The fundamental string corresponds to a photon in supersymmetric Yang-

Yao-Zhong Zhang

By generalizing the Reshetikhin and Semenov-Tian-Shansky construction to supersymmetric cases, we obtain Drinfeld current realization for quantum affine superalgebra $U_q[gl(m|n)^{(1)}]$. We find a simple coproduct for the quantum current generators and establish the Hopf algebra structure of this super current algebra.

Douglas M. Eardley

This paper treats boundary conditions on black hole horizons for the full 3+1D Einstein equations. Following a number of authors, the apparent horizon is employed as the inner boundary on a space slice. It is emphasized that a further condition is necessary for the system to be well posed; the ``prescribed curvature conditions&#34; are therefore proposed to

I. Bigi, M. Shifman, N. Uraltsev

Recent achievements in the heavy quark theory are critically reviewed. The emphasis is put on those aspects which either did not attract enough attention or cause heated debates in the current literature. Among other topics we discuss (i) basic parameters of the heavy quark theory; (ii) a class of exact QCD inequalities; (iii) new heavy quark sum rules; (iv)

I. Antoniadis, H. Partouche, T. R. Taylor

We discuss type I -- heterotic duality in four-dimensional models obtained as a Coulomb phase of the six-dimensional U(16) orientifold model compactified on T^2 with arbitrary SU(16) Wilson lines. We show that Kahler potentials, gauge threshold corrections and the infinite tower of higher derivative F-terms agree in the limit that corresponds to weak couplin

Mijo Batinic, Ivan Dadic, Ivo Slaus, Alfred Svarc

A three-channel, multi-resonance, unitary model developed in 1995 is used to determine the $πN \rightarrow ηN$ and $ηN \rightarrow ηN$ amplitudes using as input the latest data for the dominant $S_{11}$ $πN$ elastic scattering partial wave following suggestions of Prof. G. Höhler. The sign error in the numerical evaluation of the dispersion integral in the o

T. Hatsuda, Su H. Lee

In a recent paper, Eletsky and Ioffe estimated the energy shift of $ρ$-meson with high momentum (q) in nuclei using the Glauber approximation. They also made remarks on the low q vector mesons in medium. In this Comment, we will discuss the second point and show that (i) mean-field physics for the mass shift of low-q mesons is overlooked in the paper, and (i

H. Nakada, T. Otsuka

The mixed-symmetry collective modes are investigated in Cr-Fe nuclei, by analyzing the realistic shell-model wavefunctions via the H^n-cooling method. It is clarified that the relatively low-lying mixed-symmetry states behave like doorway states. For these nearly spherical nuclei, the lowest mixed-symmetry state is shown to have $J^P=2^+$. An indication of t

O. Bärwald, R. W. Gebert, M. Günaydin, H. Nicolai

We study the embedding of Kac-Moody algebras into Borcherds (or generalized Kac-Moody) algebras which can be explicitly realized as Lie algebras of physical states of some completely compactified bosonic string. The extra ``missing states&#39;&#39; can be decomposed into irreducible highest or lowest weight ``missing modules&#39;&#39; w.r.t. the relevant Kac

M. Grisaru, A. Van Proeyen, D. Zanon

The quantization of the complex linear superfield requires an infinite tower of ghosts. We use the Batalin-Vilkovisky method to obtain a gauge-fixed action. In superspace, the method brings in some novel features.

George Jaroszkiewicz, Keith Norton

We apply the principles discussed in an earlier paper to the construction of discrete time field theories. We derive the discrete time field equations of motion and Noether&#39;s theorem and apply them to the Schrodinger equation to illustrate the methodology. Stationary solutions to the discrete time Schrodinger wave equation are found to be identical to st