September 1997 arXiv papers — page 17

Uwe C. Täuber, Martin J. Howard, Haye Hinrichsen

We study a hierarchy of directed percolation (DP) processes for particle species A, B, ..., unidirectionally coupled via the reactions A -> B, ... When the DP critical points at all levels coincide, multicritical behavior emerges, with density exponents β^{(k)} which are markedly reduced at each hierarchy level k >= 2. We compute the fluctuation corrections

Ryszard Horodecki, Michal Horodecki, Pawel Horodecki

We show, by explicit examples, that the Jaynes inference scheme based on maximization of entropy can produce inseparable states even if there exists a separable state compatible with the measured data. It can lead to problems with processing of entanglement. The difficulty vanishes when one uses inference scheme based on minimization of entanglement.

Y. Strauss, L. P. Horwitz, E. Eisenberg

We discuss the quantum Lax-Phillips theory of scattering and unstable systems. In this framework, the decay of an unstable system is described by a semigroup. The spectrum of the generator of the semigroup corresponds to the singularities of the Lax-Phillips $S$-matrix. In the case of discrete (complex) spectrum of the generator of the semigroup, associated

F. Ardalan, A. H. Fatollahi, K. Kaviani, S. Parvizi

We suggest that the static configurations of M-theory may be described by the matrix regularisation of the supermembrane theory in static regime. We compute the long range interaction between a M2-brane and an anti-M2-brane in agreement with the 11 dimensional supergravity result.

Uchida Gen, Tetsuya Shiromizu

By extending Ashtekar and Romano's definition of spacelike infinity to the timelike direction, a new definition of asymptotic flatness at timelike infinity for an isolated system with a source is proposed. The treatment provides unit spacelike 3-hyperboloid timelike infinity and avoids the introduction of the troublesome differentiability conditions whic

Clarence L. Lee

In a low energy effective theory, the fields of heavy particles with mass $m$ and total momentum $p$ depend on both a velocity $v$ and a residual momentum $k$ such that $p =mv +k$. However, there is some arbitrariness in such a description because one may also use a slightly different velocity with a compensating change in the residual momentum. This non-uni

Clarence L. Lee

Starting from a theory of heavy particles and antiparticles, the path integral formulation of an effective field theory which describes the low momentum interactions is presented. The heavy degrees of freedom are identified and explicitly integrated out from the functional integral of the full theory. Using this method, the effective Lagrangian, which may be

S. Flach, K. Kladko

We give definitions for different types of moving spatially localized objects in discrete nonlinear lattices. We derive general analytical relations connecting frequency, velocity and localization length of moving discrete breathers and kinks in nonlinear one-dimensional lattices. Then we propose numerical algorithms to find these solutions. Finally we discu

A. G. Karavayev

In this paper we construct the trajectory-coherent states for the Caldirola - Kanai Hamiltonian. We investigate the properties of this states.

Oskar Pelc

A family of solvable self-dual Lie algebras is presented. There exist a few methods for the construction of non-reductive self-dual Lie algebras: an orthogonal direct product, a double-extension of an Abelian algebra, and a Wigner contraction. It is shown that the presented algebras cannot be obtained by these methods.

Axel Winterhalder

A new method to construct Hamiltonian functions in involution is presented. We show that on left-symmetric algebras a Nijenhuis-tensor is given in a natural manner by the usual right-multiplication. Furthermore we prove that symplectic Lie-algebras carry the structure of a Poisson-Nijenhuis manifold.

G. N. Throumoulopoulos, D. Pfirsch

The impact of an equilibrium radial electric field $E $ on negative-energy perturbations (NEPs) (which are potentially dangerous because they can lead to either linear or nonlinear explosive instabilities) in cylindrical equilibria of magnetically confined plasmas is investigated within the framework of Maxwell-drift kinetic theory. It turns out that for wav

Luis Gonzalez-Mestres

If textbook Lorentz invariance is actually a property of the equations describing a sector of the excitations of vacuum 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) may exist without contradicting the apparent Lorentz invariance felt by &#

S. B. Carr, I. R. Afnan, B. F. Gibson

The Nijmegen OBE potential D is SU(3) rotated to model the strangeness -2 sector of the baryon-baryon force. Soft core repulsion is introduced to regularize the singular nature of the OBE functions. The strength of the $^1$S$_0$ $t=0$ interaction is adjusted to model three scenarios: (1) a bound state, (2) a narrow virtual, or antibound, state, and (3) an un

Emilian Dudas

We analyze in detail supersymmetry breaking by compactification of the fifth dimension in M-theory in the compactification pattern $11d \to 5d \to 4d$ and find that a superpotential is generated for the complex fields coming from $5d$ hypermultiplets, namely the dilaton $S$ and the complex structure moduli. Using general arguments it is shown that these fiel

Cosmas Zachos, David Fairlie, Thomas Curtright

This is a pedagogical digest of results reported in Phys Lett B405 (1997) 37, and an explicit implementation of Euler's construction for the solution of the Poisson Bracket dual Nahm equation. But it does not cover 9 and 10-dimensional systems, and subsequent progress on them [hep-th/9707190]. Cubic interactions are considered in 3 and 7 space dimensions

Ken D. Olum

We expand on previous work involving "vacuum-bounded" states, i.e., states such that every measurement performed outside a specified interior region gives the same result as in the vacuum. We improve our previous techniques by removing the need for a finite outside region in numerical calculations. We apply these techniques to the limit of very low e

D. Delepine, R. Gonzalez Felipe, J. Weyers

Using the path-integral approach, the quantum massive Thirring and sine-Gordon models are proven to be equivalent at finite temperature. This result is an extension of Coleman's proof of the equivalence between both theories at zero temperature. The usual identifications among the parameters of these models also remain valid at $T \neq 0$.

Katrin Becker

I discuss the relation between M-theory and M(atrix)-theory in flat space by considering the effective potential for the scattering of two groups of D0-branes in both theories. An explicit calculation of this potential up to two loop order in M(atrix)-theory reveals a fascinating agreement. Lecture given at Strings '97; June 17, 1997.

I. J. R. Aitchison, C. D. Fosco

For background gauge field configurations reducible to the form Amu = (A3, A(x)) where A3 is a constant, we provide an elementary derivation of the recently obtained result for the exact induced Chern-Simons (CS) effective action in QED3 at finite temperature. The method allows us to extend the result in several useful ways: to obtain the analogous result fo

Wolfgang Ochs

A large variety of jet properties can be described perturbatively by evolving the parton cascade down to small scales of order of a few 100 MeV. We discuss two recent applications of this approach: 1. the soft limit of the particle spectrum which is nearly energy independent as expected for the soft gluon bremsstrahlung; further tests of this interpretation

Sergio Lupia, Wolfgang Ochs

Recently exact numerical results from the evolution equation for parton multiplicities in QCD jets have been obtained. A comparison with various approximate results is presented. A good description is obtained not only of the jet multiplicities measured at LEP-1 but also of the hadron multiplicities for $cms$ energies above 1.6 GeV in \epem annihilation. The

D. Gomez Dumm

We show that the extra Z boson predicted within the so-called "3-3-1" model has a leptophobic character, and analyse its effects on Z decay widths and on the t\bar t production cross section in p\bar p collisions at the Fermilab Tevatron. Recent model-independent analysis are applied in order to estimate the contribution of this Z' to the observa

A. Masiero, L. Silvestrini

In this talk we discuss rare B decays (b -> s gamma, b -> s g, b -> s l^+ l^-), B-\bar{B} oscillations and CP violation in B physics in the context of low-energy SUSY. We outline the variety of predictions that arise according to the choice of the SUSY extension ranging from what we call the "minimal" version of the MSSM to models without flavour uni

A. Masiero, L. Silvestrini

We discuss CP violation in the context of the minimal SUSY extension of the standard model as well as in a generic low-energy SUSY model. After analyzing the SUSY contributions to the observed CP violation in the kaon system, we emphasize the prospects for disentangling SUSY loop contributions from pure SM effects in B physics.

Henryk Arodz

We briefly outline the approach to extracting collective dynamics of a domain wall from field equations which has been proposed by us in Nucl.Phys.B450(1995)174-188 and further developed in hep-th/9703168.

Tancredi Carli

The main experimental results on jet production at HERA are reviewed. A study of jet shapes shows that the internal structure of jets is well understood. The potential to accurately determine the strong coupling constant using jet rates is discussed. First attempts to extract the gluon density in next-to-leading order are presented. Although fixed order pert

N. Haba, N. Okamura

We present a composite model that is based on non-perturbative effects of N=1 supersymmetric SU(N_C) gauge theory with N_f=N_C+1 flavors. In this model, we consider N_C=7, where all matter fields in the supersymmetric standard model, that is, quarks, leptons and Higgs particles are bound states of preons and anti-preons. When SU(7)_H hyper-color coupling bec

A. Hart, M. Teper

In the maximally Abelian gauge of SU(2), the clusters of monopole current are found to divide into two distinct classes. The largest cluster permeates the lattice, has a density that scales and produces the string tension. The remaining clusters possess an approximate 1/l^3 number density distribution (l is the cluster length), their radii vary as \sqrt l an

M. Hasenbusch, K. Pinn

We present estimates for the 3D Ising model on the cubic lattice, both regarding interface and bulk properties. We have results for the interface tension, in particular the amplitude sigma0 in the critical law sigma = sigma0*t**mu, and for the universal combination R_ = sigma*xi**2. Concerning the bulk properties, we estimate the specific heat universal ampl

Michael P. Ryan,, Sergio M. Waller

The application of the divergence theorem in a non-coordinated basis is shown to lead to a corrected variational principle for Class B Bianchi cosmological models. This variational principle is used to construct a Hamiltonian formulation for diagonal and symmetric vacuum Class B models. [Note: This is an unpublished paper from 1984 that might be useful to an

Clifford M. Will

If gravitation is propagated by a massive field, then the velocity of gravitational waves (gravitons) will depend upon their frequency and the effective Newtonian potential will have a Yukawa form. In the case of inspiralling compact binaries, gravitational waves emitted at low frequency early in the inspiral will travel slightly slower than those emitted at

M. O. Katanaev, W. Kummer, H. Liebl, D. V. Vassilevich

All 1+1 dimensional dipheomorphism-invariant models can be viewed in a unified manner. This includes also general dilaton theories and especially spherically symmetric gravity (SSG) and Witten's dilatonic black hole (DBH). A common feature --- also in the presence of matter fields of any type --- is the appearance of an absolutely conserved quantity C wh

S. S. Banerjee

CeRu2 and 2H-NbSe2 display remarkable similarities in their magnetic response, reflecting the manner in which the weakly pinned flux line lattice (FLL) loses spatial order in the Peak Effect (PE) regime. The discontinuous change in screening response near the onset of PE and the history dependence in it are attributed to a disorder-induced fracturing transit

P. M. C. de Oliveira, T. J. P. Penna, H. J. Herrmann

We propose a new Monte Carlo technique in which the degeneracy of energy states is obtained with a Markovian process analogous to that of Metropolis used currently in canonical simulations. The obtained histograms are much broader than those of the canonical histogram technique studied by Ferrenberg and Swendsen. Thus we can reliably reconstruct thermodynami

Niurka R. Quintero, Angel Sánchez

We investigate the possibility of dc soliton motion sustained by pure ac driving in the sine-Gordon model. We show by means of the collective coordinate formalism that ac driving induces a net dc velocity whose modulus and direction depend on the driving phase. Numerical simulations of the full sine-Gordon equation confirm the correctness and accuracy of thi

M. Argollo de Menezes, T. J. P. Penna

In this work we revisit the Hopfield-Tank algorithm for the traveling salesman problem (TSP) and report encouraging results, with a different dynamics, that makes the algorithm more efficient finding better solutions in much less computational time.

R. Movshovich, M. A. Hubbard, M. B. Salamon, A. V. Balatsky

We report the discovery of a low-temperature phase transition in Bi_2Sr_2Ca(Ni_xCu_{1-x})_20_8 high temperature superconductor. This transition manifests itself as a sharp reduction of the thermal conductivity of the samples at a temperature of T_c* \approx 200 mK. The temperature dependence of the thermal conductivity changes dramatically from T^αwith αbetw

M. A. Korotin, S. Yu. Ezhov, I. V. Solovyev, V. I. Anisimov

The electronic structure of the perovskite LaCoO$_3$ for different spin states of Co ions was calculated in the LDA+U approach. The ground state was found to be a nonmagnetic insulator with Co ions in a low-spin state. Somewhat higher in energy we found two intermediate-spin states followed by a high-spin state at significantly higher energy. The calculation

Hans C. Fogedby

The morphology and scaling properties of the noisy Burgers equation in one dimension are treated by means of a nonlinear soliton approach based on the Martin-Siggia-Rose technique. In a canonical formulation the strong coupling fixed point is accessed by means of a principle of least action in the asymptotic nonperturbative weak noise limit. The strong coupl

Hans C. Fogedby

The noiseless Burgers equation in one spatial dimension is analyzed from the point of view of a diffusive evolution equation in terms of nonlinear soliton modes and linear diffusive modes. The transient evolution of the profile is interpreted as a gas of right hand solitons connected by ramp solutions with superposed linear diffusive modes. This picture is s

I. Ya. Korenblit, V. Cherepanov, Amnon Aharony, O. Entin-Wohlman

In doped lamellar cuprates, localized holes create ferromagnetic bonds and cause spin canting similar to that caused by magnetic dipoles. At low temperatures, these dipoles are frozen, behaving like quenched correlated random fields. Renormalization group methods are used to show that such impurities cause a strong reduction of the two-dimensional antiferrom

S. Conti, G. Vignale

We calculate the spectral function of a smooth edge of a quantum Hall system in the lowest Landau level by means of a bosonization technique. We obtain a general relationship between the one electron spectral function and the dynamical structure factor. The resulting I-V characteristics exhibit, at low voltage and temperature, power law scaling, generally di

G. F. De Angelis, G. Jona-Lasinio, V. Sidoravicius

We show that the calculation of Berezin integrals over anticommuting variables can be reduced to the evaluation of expectations of functionals of Poisson processes via an appropriate Feynman-Kac formula. In this way the tools of ordinary analysis can be applied to Berezin integrals and, as an example, we prove a simple upper bound. Possible applications of o

T. Alarcon, A. Perez-Madrid, J. M. Rubi

We have studied the relaxation and transport properties of a ferrofluid in an elongational flow. These properties are influenced by the bistable nature of the potential energy. Bistability comes from the irrotational character of the flow together with the symmetry of the dipoles. Additionally, the presence of a constant magnetic field destroys the symmetry

M. J. Martins, B. Nienhuis, R. Rietman

In this paper we investigate an integrable loop model and its connection with a supersymmetric spin chain. The Bethe Ansatz solution allows us to study some properties of the ground state. When the loop fugacity $q$ lies in the physical regime, we conjecture that the central charge is $c=q-1$ for $q$ integer $< 2$. Low-lying excitations are examined, support

Takaaki Kawaguchi, Hiroshi Matsukawa

Dynamical frictional phenomena are studied theoretically in a two-chain model with incommensurate structure. A perturbation theory with respect to the interchain interaction reveals the contributions from phonons excited in each chain to the kinetic frictional force. The validity of the theory is verified in the case of weak interaction by comparing with num

S. Flach, K. Kladko, S. Takeno

The existence of breathers (time-periodic and spatially localized lattice vibrations) is well established for i) systems without acoustic phonon branches and ii) systems with acoustic phonons, but also with additional symmetries preventing the occurence of strains (dc terms) in the breather solution. The case of coexistence of strains and acoustic phonon bra

Reinhold Egger, Hermann Grabert

Screening in one-dimensional metals is studied for arbitrary electron-electron interactions. It is shown that for finite-range interactions (Luttinger liquid) electroneutrality is violated. This apparent inconsistency can be traced to the presence of external screening gates responsible for the effectively short-ranged Coulomb interactions. We also draw atte

S. Flach, K. Kladko

We study the effects of electron-lattice interaction in the presence of discrete breathers. The lattice is treated classically. We consider two different situations - i) the scattering of an electron by a discrete breather in the semiconducting regime, where the electron-breather distance is large compared to the breather size, and ii) the appearance of a bo

Siegfried Grossmann, Martin Holthaus

We question the validity of the grand canonical ensemble for the description of Bose-Einstein condensation of small ideal Bose gas samples in isolated harmonic traps. While the ground state fraction and the specific heat capacity can be well approximated with the help of the conventional grand canonical arguments, the calculation of the fluctuation of the nu

K. Kladko, P. Fulde

Cumulants represent a natural language for expressing macroscopic properties of a solid. We show that cumulants are subject to a nontrivial geometry. This geometry provides an intuitive understanding of a number of cumulant relations which had been obtained so far by using algebraic considerations. We give general expressions for their infinitesimal and fini

B. Galanti, J. D. Gibbon, M. Heritage

We address the problem in Navier-Stokes isotropic turbulence of why the vorticity accumulates on thin sets such as quasi-one-dimensional tubes and quasi-two-dimensional sheets. Taking our motivation from the work of Ashurst, Kerstein, Kerr and Gibson, who observed that the vorticity vector ${\boldmath$ω$}$ aligns with the intermediate eigenvector of the stra

Stefanie Wachter

We present optical photometry of the low mass X-ray binary systems GX 349+2 and Ser X-1. Extensive VRI photometry of the faint optical counterpart (V=18.4) to GX 349+2 reveals a period of 22.5 +/- 0.1 h and half-amplitude 0.2 mag. This result confirms and extends our previously reported 22 h period. No color change is detected over the orbit, although the li

Jason Harris, Dennis Zaritsky, Ian Thompson

We present a detailed map of the reddening in a 1.9 x 1.5 degree section of the Large Magellanic Cloud, constructed from UBVI photometry of 2069 O and B main sequence stars. We use two reddening-free photometric parameters to determine the line-of-sight reddening to these stars. We find <E(B-V)>=0.20 mag, with a non-Gaussian tail to high values. When the red

David S. Davis, Raymond E. White

We present a spatially resolved map of intracluster gas temperatures in the rich cluster Abell 2255, using ROSAT PSPC data. The intracluster gas is strongly non-isothermal and the temperature distribution supports the conclusions of Burns et al. (1995) that Abell~2255 is currently undergoing a merger. The hottest regions are near the core, northwest of the c

M. Federspiel, G. A. Tammann, A. Sandage

The distance of the Virgo cluster is derived in the B band from the 21 cm-line width-absolute magnitude relation. The latter is calibrated using 18 spirals with Cepheid distances mainly from HST. The calibration is applied to a complete sample of non-peculiar spirals with i>45 deg and lying within the optical (n=49) or X-ray (n=35) contour of the cluster, re

Marc Turler, Thierry J. -L. Courvoisier

We apply a principal component analysis (PCA) to the spectra of each of the 18 Seyfert 1-like objects observed more than 15 times by the international ultraviolet explorer (IUE) from 1978 until the end of 1991. PCA allows us to decompose the Lyman alpha and the C IV (1549 A) emission-lines of each object into two components with uncorrelated variations. We f

G. V. Bicknell, M. A. Dopita, Z. Tsvetanov, R. S. Sutherland

We argue that the narrow line regions of Seyfert galaxies are powered by the transport of energy and momentum by the radio-emitting jets and consequently that the ratio of the radio power to jet energy flux is much smaller than is usually assumed for radio galaxies. This can be partially attributed to the smaller ages ($\sim 10^6 yrs$) of Seyferts compared t

M. J. Way, H. Quintana, L. Infante

A dynamical analysis of the structure of the clusters of galaxies Abell 119 and Abell 133 is presented, using new redshift data combined with existing data from the literature. We compare our results with those from the X-ray data for these clusters, and with those from radio data for the central cD galaxy in each cluster. A comparison of the mass estimate b

Philip J. Armitage, Mario Livio

We use hydrodynamic simulations to provide quantitative estimates of the effects of the impact of the accretion stream on disks in interacting binaries. For low accretion rates, efficient radiative cooling of the hotspot region can occur, and the primary consequence of the stream impact is stream overflow toward smaller disk radii. The stream is well describ

A. J. Barth, G. A. Reichert, L. C. Ho, J. C. Shields

As a step towards clarifying the ionization mechanism of LINERs, we have used the Hubble Space Telescope Faint Object Spectrograph to obtain an ultraviolet spectrum of the nucleus of NGC 6500. Compared with more luminous Seyfert nuclei, the emission-line spectrum of NGC 6500 is remarkable for its low-excitation character: C III], C II], and Mg II are the str

Peter Hoeflich, J. Craig Wheeler, Alexei Khokhlov

The gamma-ray light curves and spectra are presented for a set of theoretical Type Ia supernova models including deflagration, detonation, delayed detonation, and pulsating delayed detonations of Chandrasekhar mass white dwarfs as well as merger scenarios that may involve more than the Chandrasekhar mass and helium detonations of sub-Chandrasekhar mass white

Ravi Vakil

As another application of the degeneration methods of [V3], we count the number of irreducible degree $d$ geometric genus $g$ plane curves, with fixed multiple points on a conic $E$, not containing $E$, through an appropriate number of general points in the plane. As a special case, we count the number of irreducible genus $g$ curves in any divisor class $D$

Ravi Vakil

In this paper we study the geometry of the Severi varieties parametrizing curves on the rational ruled surface $\fn$. We compute the number of such curves through the appropriate number of fixed general points on $\fn$, and the number of such curves which are irreducible. These numbers are known as Severi degrees; they are the degrees of unions of components

Vicente Muñoz

We extend the ideas of Friedman and Qin (Flips of moduli spaces and transition formulae for Donaldson polynomial invariants of rational surfaces) to find the wall-crossing formulae for the Donaldson invariants of algebraic surfaces with geometrical genus zero, positive irregularity and anticanonical divisor effective, for any wall $ζ$ with $l_ζ=(ζ\sp{2}-p_1)

A. Racco, M. Argollo de Menezes, T. J. P. Penna

In this work we check the occurrence of the Azbel assumption of mortality within the framework of a bit string model for biological ageing. We reproduced the observed feature of linear correspondence between the fitting parameters of the death rate as obtained by Azbel with demographic data.

A. M. Dyugaev, Yu. N. Ovchinnikov, P. Fulde

It is found that in a wide range of temperatures and magnetic fields even a small concentration of magnetic impurities in a sample leads to a $T^{-1}$ temperature dependence of the nuclear heat capacity. This effect is related to a nuclear-spin polarization by the magnetic impurities. The parameter that controls the theory turns out not to be the impurity co

Yu. N. Ovchinnikov, A. M. Dyugaev, V. Z. Kresin, P. Fulde

The paper has been withdrawn.

Mirjam Cvetic, Christopher M. Hull

Configurations of two or more branes wrapping different homology cycles of space-time are considered and the amount of supersymmetry preserved is analysed, generalising the analysis of multiple branes in flat space. For K3 compactifications, these give the Type II or M theory origin of certain supersymmetric four-dimensional heterotic string solutions that f

S. Catterall, R. Renken, J. Kogut

We show that the phase transition previously observed in dynamical triangulation models of quantum gravity can be understood as being due to the creation of a singular link. The transition between singular and non-singular geometries as the gravitational coupling is varied appears to be first order.

Philip R. Page

Recent experimental data from BNL on the isovector J^PC =1^-+ exotic at 1.6 GeV in ρπindicate the existence of a non-quarkonium state consistent with lattice gauge theory predictions. We discuss how further experiments can strengthen this conclusion. We show that the ρπ, η&#39;πand ηπcouplings of this state qualitatively support the hypothesis that it is a h

Carlo Del Noce, Giovanni Preti, Fernando de Felice

The end state of a coalescing binary of compact objects depends strongly on the final total mass M and angular momentum J. Since gravitational radiation emission causes a slow evolution of the binary system through quasi-circular orbits down to the innermost stable one, in this paper we examine the corresponding behavior of the ratio J/M^2 which must be less

Thomas Wynter

It is shown that all possible N sheeted coverings of the cylinder are contained in type IIA matrix string theory as non-trivial gauge field configurations. Using these gauge field configurations as backgrounds the large $N$ limit is shown to lead to the type IIA conformal field theory defined on the corresponding Riemann surfaces. The sum over string diagram

Valery P. Gusynin, Vadim M. Loktev, Sergei G. Sharapov

A phase diagram for a 2D metal with variable carrier density has been derived. It consists of a normal phase, where the order parameter is absent; a so-called ``abnormal normal&#39;&#39; phase where this parameter is also absent but the mean number of composite bosons (bound pairs) exceeds the mean number of free fermions; a pseudogap phase where the absolut

J. -J. Dugne, S. Fredriksson, J. Hansson, E. Predazzi

The Higgs mechanism is the favourite cure for the main problem with electroweak unification, namely how to reconcile a gauge theory with the need for massive gauge bosons. This problem does not exist in preon models for quark and lepton substructure with composite $Z^0$ and $W$s, which, consequently, also avoid all other theoretical complications and paradox

Wenjun Zheng, Yue Yu

Based on a newly derived microscopic fractional quantum Hall edge model, we study its thermodynamics at finite temperature. For the dressed energy spectrum a critical energy scale determined by the temperature exists, below which the refractive dispersion which is essential to the model&#39;s bosonization to a Luttinger liquid is smeared. According to this o

A. A. Deriglazov

A covariant action for closed D=11 superstring with local $κ$-symmetry and global supersymmetry transformations obeying the algebra $\{Q_α,Q_β\}=CΓ^{μν}P_μn_ν$ is suggested. Physical sector variables of the model and their dynamics exactly coincide with those of the D=10 type IIA Green-Schwarz superstring. It is shown that action of the D=10 type IIA Green-S

R. Schützhold, G. Plunien, G. Soff

We present a canonical formalism facilitating investigations of the dynamical Casimir effect by means of a response theory approach. We consider a massless scalar field confined inside of an arbitaray domain $G(t)$, which undergoes small displacements for a certain period of time. Under rather general conditions a formula for the number of created particles

Angel Ballesteros, Francisco J. Herranz, Preeti Parashar

The non-standard quantum deformation of the (trivially) extended sl(2,R) algebra is used to construct a new quantum deformation of the two-photon algebra h_6 and its associated quantum universal R-matrix. A deformed one-boson representation for this algebra is deduced and applied to construct a first order deformation of the differential equation that genera

B. M. Garraway, K. -A. Suominen

We present the APLIP process (Adiabatic Passage by Light Induced Potentials) for the adiabatic transfer of a wave packet from one molecular potential to the displaced ground vibrational state of another. The process uses an intermediate state, which is only slightly populated, and a counterintuitive sequence of light pulses to couple the three molecular stat

N. A. Zabotin, A. G. Bronin

The problem of radio wave reflection from an optically thick plane monotonous layer of magnetized plasma is considered at present work. The plasma electron density irregularities are described by spatial spectrum of an arbitrary form. The small-angle scattering approximation in the invariant ray coordinates is suggested for analytical investigation of the ra

M. Umeki

It is shown that, by letting wavenumbers and frequencies complex in Hirota&#39;s bilinear method, new classes of exact solutions of soliton equations can be obtained systematically. They include not only singular or N-homoclinic solutions but also N-wavepacket solutions.

V. Fateev, S. Lukyanov, A. Zamolodchikov, Al. Zamolodchikov

Exact expectation values of the fields e^{aϕ} in the Bullough-Dodd model are derived by adopting the ``reflection relations&#39;&#39; which involve the reflection S-matrix of the Liouville theory, as well as special analyticity assumption. Using this result we propose explicit expressions for expectation values of all primary operators in the c<1 minimal CFT

J. J. M. Verbaarschot

In these two lectures given at the 1997 Zakopane workshop on &#34;New Developments in Quantum Field Theory&#34; we review recent results on universal fluctuations in QCD Dirac spectra. We start the first lecture with a review of some general properties of Dirac spectra. It will be argued that there is an intimate relation between chiral symmetry breaking and

Maxime Kudinov, Enrique Moreno, Peter Orland

We describe an approach to understanding exponential decay of correlation functions in asymptotically free theories. This approach is systematic; it does not start from any conjectured mechanism or picture. We begin by studying the metric on the space of configurations and the behavior of the potential-energy function on this space. We describe how these ide

Andre Lukas, Burt A. Ovrut

A manifestly U-duality covariant approach to M-theory cosmology is developed and applied to cosmologies in dimensions D=4,5. Cosmological properties such as expansion powers and Hubble parameters turn out to be U-duality invariant in certain asymptotic regions. U-duality transformations acting on cosmological solutions, on the other hand, shift the transitio

G. Delfino, G. Mussardo

We consider the two-dimensional quantum field theory of a scalar field self-interacting via two periodic terms of frequencies $α$ and $β$. Looking at the theory as a perturbed Sine-Gordon model, we use Form Factor Perturbation Theory to analyse the evolution of the spectrum of particle excitations. We show how, within this formalism, the non-locality of the

G. W. Gibbons

Born-Infeld theory admits finite energy point particle solutions with $δ$-function sources, BIons. I discuss their role in the theory of Dirichlet $p$-branes as the ends of strings intersecting the brane when the effects of gravity are ignored. There are also topologically non-trivial electrically neutral catenoidal solutions looking like two $p$-branes join

Boguslaw Broda

Using physical arguments (Higgs mechanism, superconductivity, infrared regime, duality) and a geometric-topological construction (scalar curvature distribution compatible with surgery), we propose a topological interpretation of 3D SW theory in terms of the abelian Casson invariant. Further algebraic reasoning shows equivalence of that invariant to the Alexa

Thomas G. Rizzo

Attempts to understand the recent observation of an excess of events in the neutral and charged current channels at high$-Q^2$ at HERA has provided an excellent example of how experiments at both low and high energies can be used to simultaneously constrain scenarios which predict new physics beyond the Standard Model. In this talk I will discuss this subjec

A. Love, P. Stadler

The supersymmetry breaking parameters and the resulting supersymmetric particle spectrum are studied in orbifold compactifications of string theory under the assumption that unification of gauge coupling constants at about $10^{16}$ GeV is a consequence of large moduli dependent string loop threshold corrections. The effect on the spectrum of various assumpt

Alan R. White

Deep-inelastic diffractive scaling provides fundamental insight into the QCD pomeron. It is argued that single gluon domination of the structure function, together with the well-known Regge pole property, determines that the pomeron carries color-charge parity $ C_c = -1~$ and, at short distances, is in a super-critical phase of Reggeon Field Theory. The mai

D. Boyanovsky, D. Cormier, H. J. de Vega, R. Holman

We consider an O(N) model coupled self-consistently to gravity in the semiclassical approximation, where the field is subject to `new inflation&#39; type initial conditions. We study the dynamics self-consistently and non-perturbatively with non-equilibrium field theory methods in the large N limit. We find that spinodal instabilities drive the growth of non

P. Zenczykowski

It is pointed out that current conservation alone does not suffice to prove Hara&#39;s theorem as it was claimed recently. By explicit calculation we show that the additional implicit assumption made in such &#34;proofs&#34; is that of a sufficiently localized current.

D. Bardin, W. Beenakker, M. Bilenky, W. Hollik

The report summarizes the results of the activities of the Working Group on Precision Calculations for the Z Resonance at CERN during 1994.

Benjamin Svetitsky, Asher Uziel

A charmed quark experiences drag and diffusion in the quark-gluon plasma, as well as strong interaction with the plasma surface. Our simulations indicate that charmed quarks created in heavy ion collisions will be trapped in the mixed phase and will come to equilibrium in it. Their momentum distribution will thus reflect the temperature at the confinement ph

Eugene Levin

In this talk, I will argue that the HERA experimental data show that the typical parameter ($κ$) responsible for the value of the shadowing corrections (SC) in DIS is so large that the BFKL Pomeron is hidden under SC. The SC turn out to be large enough but mostly for the gluon structure function which is not well determined by the available experimental data

P. Poulose, Saurabh D. Rindani

CP-violating asymmetries due to a possible electric dipole interaction of the top quark in the production and subsequent decay of top quark-top antiquark pair in photon-photon collisions are studied. The asymmetries defined can be used to determine the imaginary part of the electric dipole form factors. A gamma-gamma collider with photon beams generated from

K. Pinn, S. Vinti

Using a variant of the IMCRG method of Gupta and Cordery, we explicitly compute majority rule block spin effective actions for the signs of the Polyakov loops in 4D SU(2) finite temperature lattice gauge theories. To the best of our knowledge, this is the first attempt to compute numerically effective actions for the Polyakov loop degrees of freedom in 4D SU