April 2000 arXiv papers — page 3

Albert Schwarz

We introduce a notion of Q-algebra that can be considered as a generalization of the notion of Q-manifold (a supermanifold equipped with an odd vector field obeying {Q,Q} =0). We develop the theory of connections on modules over Q-algebras and prove a general duality theorem for gauge theories on such modules. This theorem contains as a simplest case SO(d,d,

Dan Radu Grigore

We present an extremely simple solution to the renormalization of quantum electrodynamics based on Epstein-Glaser approach to renormalization theory.

Ben Craps

In this Ph.D. thesis, we study some aspects of strings and branes. We mainly focus on anomalous D-brane couplings and on non-supersymmetric branes. In Chapter 2, we illustrate three key concepts in a field theory context: duality, supersymmetry and anomaly inflow. Chapter 3 contains an introduction to string theory, emphasizing the concepts relevant to this

Claudio Nassif, P. R. Silva

In this work we apply Thompson's method (of the dimensions) to study the quantum electrodynamics (QED). This method can be considered as a simple and alternative way to the renormalisation group (R.G) approach and when applied to QED lagrangian is able to obtain the running coupling constant behavior $α(μ)$, namely the dependence of $α$ on the energy sca

A. Harindranath, Asmita Mukherjee, Raghunath Ratabole

In this work we initiate a systematic investigation of the spin of a composite system in an arbitrary reference frame in QCD. After a brief review of the difficulties one encounters in equal-time quantization, we turn to light-front quantization. We show that, in spite of the complexities, light-front field theory offers a unique opportunity to address the i

Rabin Banerjee, Clovis Wotzasek

We propose bosonised expressions for the chiral Schwinger models in four dimensions. Then, in complete analogy with the two dimensional case, we show the soldering of two bosonised chiral Schwinger models with opposite chiralities to yield the bosonised Schwinger model in four dimensions. The implications of the Schwinger model or its chiral version, as know

Hiroki Hata, Shun-ichi Yamaguchi

We obtain logarithmic behaviours of a four-point correlation function in the c=-2 conformal field theory by using the Feigin-Fuchs construction. It becomes an indeterminate form by a naive evaluation, but is obtained by introducing an appropriate regularization procedure.

Kenji Ito, Masashi Naganuma, Hodaka Oda, Norisuke Sakai

Using an exact solution as a concrete example, Nambu-Goldstone modes on the BPS domain wall junction are worked out for N=1 supersymmetric theories in four dimensions. Their wave functions extend along the wall to infinity (not localized) and are not normalizable. It is argued that this feature is a generic phenomenon of Nambu-Goldstone modes on domain wall

Albert Schwarz

We analyze the perturbation series for noncommutative eigenvalue problem $AX=Xλ$ where $λ$ is an element of a noncommutative ring, $ A$ is a matrix and $X$ is a column vector with entries from this ring. As a corollary we obtain a theorem about the structure of perturbation series for Tr $x^r$ where $x$ is a solution of noncommutative algebraic equation (for

T. A. Trainor, J. G. Reid

We extend the usual treatment of two-particle momentum correlations to include the possibility of non-chaotic or correlated particle emission from the hadronic freeze-out surface in heavy-ion collisions. We adopt a modified two-particle emission density which permits the description of nontrivial differences between pair autocorrelations for different pair t

M. B. Voloshin

A compact review of the theory, including some recent developments, of inclusive weak decay rates of charmed and b hadrons with an emphasis on predictions that can be tested in the forthcoming experiments.

Claudio Nassif, P. R. Silva

In this work we propose an action to describe diffusion limited chemical reactions belonging to various classes of universality. This action is treated through Thompson's approach and can encompass both cases where we have segregation as in the $A+B\to 0$ reaction, as well the simplest one, namely the $A+A\to 0$ reaction .Our results for long time and lo

J. Franz, E. Rossle, H. Schmitt, L. Schmitt

Differential cross sections of elastic neutron-proton scattering have been measured for the energy range from 200 MeV to 580 MeV. The angular interval for the detection of the recoiling proton ranges up to 48 degree in the laboratory system. This corresponds to an interval of the scattering angle from 80 degree to 180 degree in the centre-of-mass system. For

Patricia Ball

We investigate the pattern of CP violation in \Kd, \Bd and \Bs mixing in a symmetrical \model model with spontaneous CP violation. Performing a careful analysis of all relevant restrictions on the model's parameters from $ΔM_K$, $ΔM_{B_d}$, $ΔM_{B_s}$, $ε_K$, the sign of \ee and the mixing-induced CP asymmetry in \goldd, we find that the mass of the righ

F. E. Close, A. Kirk

For the first time a complete data set of the two-body decays of the f0(1370), f0(1500) and f0(1710) into all pseudoscalar mesons is available. The implications of these data for the flavour content for these three f0 states is studied. We find that they are in accord with the hypothesis that the scalar glueball of lattice QCD mixes with the qqbar nonet that

I. Antoniadis, K. Benakli

We give a brief summary of present bounds on the size of possible extra-dimensions from collider experiments.

Kai Puolamaki

Four different supersymmetric models based on SU(2)_L X U(1)_R X U(1)_B-L and SU(2)_L X SU(2)_R X U(1)_B-L gauge symmetry groups are studied. U(1)_B-L symmetry is broken spontaneously by a vacuum expectation value (VEV) of a sneutrino field. The right-handed gauge bosons may obtain their mass solely by sneutrino VEV. The physical charged lepton and neutrino

P. Avery

We present a study of three B0 decay modes useful for time-dependent CP asymmetry measurements. From a sample of 9.7 million B meson pairs collected with the CLEO detector, we have reconstructed B0 -> J/psi K0S, B0 -> chi_c1 K0S, and B0 -> J/psi pi0 decays. The latter two decay modes have been observed for the first time. We describe a K0S -> pi0 pi0 detecti

H. Albrecht, ARGUS Collaboration

Using the ARGUS detector at the e+e- storage ring DORIS II, we have searched for the real and imaginary part of the electric dipole formfactor d_tau of the tau lepton in the production of tau pairs at q^2=100 GeV^2. This is the first direct measurement of this CP violating formfactor. We applied the method of optimised observables which takes into account al

M. Ouchrif

We present a sudy of the interactions of Q-balls with matter, and their energy losses in the earth, for a large range of velocities. These calculations are used to computethe fractional geometrical acceptance of underground detectors. Furthermore we computed the light yield in liquidscintillators, the ionization in streamer tubes and the Restricted Energy Lo

Yi-Ping Qin

By extending the exterior Schwarzschild spacetime in two opposite directions with the Kruskal method, we get an extension which has the same T-X spacetime diagram as has the conventional Kruskal extension, while allowing its regions I and IV to correspond to different directions of the original spacetime. We further extend the exterior Schwarzschild spacetim

Lin Tian, L. S. Levitov, Caspar H. van der Wal, J. E. Mooij

Decoherence of a solid state based qubit can be caused by coupling to microscopic degrees of freedom in the solid. We lay out a simple theory and use it to estimate decoherence for a recently proposed superconducting persistent current design. All considered sources of decoherence are found to be quite weak, leading to a high quality factor for this qubit.

Amit Ghosal, Mohit Randeria, Nandini Trivedi

We study a short coherence length d-wave superconductor with finite density of unitary scatterers using the Bogoliubov-deGennes technique. We find that the low-energy density of states is reduced, the superfluid stiffness is significantly larger and off-diagonal long range order is more robust than the self-consistent T-matrix prediction. These results are a

J. Gonzalez

We devise a computational approach to the Hubbard model that captures the strong coupling dynamics arising when the Fermi level is at a Van Hove singularity in the density of states. We rely on an approximate degeneracy among the many-body states accounting for the main instabilities of the system (antiferromagnetism, d-wave superconductivity). The Fermi lin

K. Park, J. K. Jain

The true nature of the lowest-energy, long-wavelength neutral excitation of the fractional quantum Hall effect has been a long outstanding problem. In this Letter, we establish that it is a two-roton bound state.

Marcelo R. Ubriaco

We study the long range behavior of a gas whose partition function depends on a parameter q and it has been claimed to be a good approximation to the partition function proposed in the formulation of nonextensive statistical mechanics. We compare our results, at large temperatures and at the critical point, with the case of Boltzmann-Gibbs thermodynamics for

Behnam Farid

For uniform systems of spin-less fermions in d spatial dimensions with d > 1, interacting through the isotropic two-body potential v(r-r&#39;), a celebrated theorem due to Luttinger (1961) states that under the_assumption_ of validity of the many-body perturbation theory the self-energy Sigma(k;epsilon), with 0 <,= k <,~ 3 k_F (where k_F stands for the Fermi

H. J. Lee, K. H. Kim, J. H. Jung, T. W. Noh

Optical conductivity spectra of a cleaved ab-plane of a La_{1.2}Sr_{1.8}Mn_2O_7 single crystal exhibit a small polaron absorption band in the mid-infrared region at overall temperatures. With decreasing temperature (T) to Curie temperature (T_C), the center frequency of the small polaron band moves to a higher frequency, resulting in a gap-like feature, and

Ronald Blaak

We consider the consequences of keeping the total surface fixed for a polydisperse system of $N$ hard spheres. In contrast with a similar model (J. Zhang {\it et al.}, J. Chem. Phys. {\bf 110}, 5318 (1999)), the Percus-Yevick and Mansoori equations of state work very well and do not show a breakdown. For high pressures Monte Carlo simulation we show three me

L. Acedo

The continuity conditions of the radial distribution function g(r) and its close relative the cavity function y(r) are studied in the context of the Percus-Yevick (PY) integral equation for 3D square-well fluids. The cases corresponding to a well width, (w-1)*d, equal to a fraction of the diameter of the hard core, d/m, with m=1,2,3 have been considered. In

P. Silvestrini, L. Stodolsky

We suggest a procedure for demonstrating quantum coherence and measuring decoherence times between different fluxoid states of a SQUID by using ``adiabatic inversion&#39;&#39;, where one macroscopic fluxoid state is smoothly transferred into the other, like a spin reversing direction by following a slowly moving magnetic field. This is accomplished by sweepi

C. Bourbonnais

In this brief account, we shall review the different mechanisms giving rise to itinerant and localized antiferromagnetism in quasi-one-dimensional organic conductors: the Bechgaard salts and their sulfur analogs. We will then focus on the problem of spin correlations and their impact on the pairing mechanism for organic superconductivity.

Magdalena A. Zaluska-Kotur, Mariusz Gajda, Arkadiusz Orlowski, Jan Mostowski

We study a system of trapped bosonic particles interacting by model harmonic forces. Our model allows for detailed examination of the notion of an order parameter (a condensate wave function). By decomposing a single particle density matrix into coherent eigenmodes we study an effect of interaction on the condensate. We show that sufficiently strong interact

Mariusz Gajda, Magdalena A. Zaluska-Kotur, Jan Mostowski

We study exactly soluble system of trapped bosonic particles interacting by a model harmonic forces. The model allows for detailed examination of the order parameter (condensate wave function) as well as concept of the off-diagonal and diagonal order. We analyze the effect of interactions on the condensate and show that sufficiently strong interactions, attr

K. H. Kim, M. Uehara, S-W. Cheong

High temperature (T) studies of La_{1-x}Ca_{x}MnO_{3} show that charge and phonon transport is significantly suppressed in a narrow doping region of x~1/2 and in a wide T range up to 900 K, which accompanies anomalous broadening of x-ray Bragg peaks. Contrarily, ferromagnetic (FM) correlation above Curie T is sharply enhanced at x~3/8. All these observations

A. Lipowski, D. Johnston, D. Espriu

Using Monte Carlo simulations we study the dynamics of three-dimensional Ising models with nearest-, next-nearest-, and four-spin (plaquette) interactions. During coarsening, such models develop growing energy barriers, which leads to very slow dynamics at low temperature. As already reported, the model with only the plaquette interaction exhibits some of th

D. Controzzi, A. M. Tsvelik

We consider two families of exactly solvable models describing thermal fluctuations in two-dimensional superconductors coupled to phonons living in an insulating layer, and study the stability of the superconducting state with respect to vortices. The two families are characterized by one or two superconducting planes. The results suggest that the effective

Ph. Ghosez, D. Desquesnes, X. Gonze, K. M. Rabe

Using first-principles calculations based on a variational density functional perturbation theory, we investigate the lattice dynamics of solid solutions of barium and strontium titanates. Averaging the information available for the related pure compounds yields results equivalent to those obtained within the virtual crystal approximation, providing frequenc

Anthony Roberts, Mark Knackstedt

We investigate the influence of fractal structure on material properties. We calculate the statistical correlation functions of fractal media defined by level-cut Gaussian random fields. This allows the modeling of both surface fractal and mass fractal materials. Variational bounds on the conductivity, diffusivity and elastic moduli of the materials are eval

Anthony Roberts, Max Teubner

We investigate the effective conductivity ($σ_e$) of a class of amorphous media defined by the level-cut of a Gaussian random field. The three point solid-solid correlation function is derived and utilised in the evaluation of the Beran-Milton bounds. Simulations are used to calculate $σ_e$ for a variety of fields and volume fractions at several different co

Xiaoqing Yu, Congjun Wu, Chui-lin Wang, Zhao-Bin Su

The extended SSH model and Bogoliubov-de Gennes(BdeG) formalism are applied to investigate the electronic properties and stable lattice configurations of C$_{36}$. We focus the problem on the molecule&#39;s unusual $D_{6h}$ symmetry. The electronic part of the Hamiltonian without Coulomb interaction is solved analytically. We find that the gap between HOMO a

J. Lopez, P. N. Lisboa-Filho, W. A. C. Passos, W. A. Ortiz

We present an extensive study of the time dependence of the magnetization in a polycrystalline and low temperature charge ordered La0.5Ca0.5MnO3 sample. After application and removal of a 5 T magnetic field, a systematic variation of the magnetic relaxation rate from 10 K to 245 K was found. At 195 K, the magnetization decreases in a very short time and afte

S. Savaglio, N. Panagia, M. Stiavelli

We have collected data for 69 Damped Lyman-alpha (DLA) systems, to investigate the chemical evolution of galaxies in the redshift interval 0.0 < z < 4.4. In doing that, we have adopted the most general approach used so far to correct for dust depletion. The best solution, obtained through chi^2 minimization, gives as output parameters the global DLA metallic

Adam Frank, Thomas A. Gardiner

Hypersonic, highly collimated, mass outflows ({\it jets}) are a ubiquitous phenomena in astrophysics. While the character of the jets differ, many exhibit some form of quasi-periodic clumping indicating the jet source is episodic or {\it pulsed}. The presence of pulsed jets in so many astrophysical contexts suggests a common formation mechanism. Such a proce

K. L. Luhman, G. H. Rieke, Erick T. Young, Angela S. Cotera

We have obtained images of the Trapezium Cluster (140&#34; x 140&#34;; 0.3 pc x 0.3 pc) with the Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Combining these data with new ground-based K-band spectra (R=800) and existing spectral types and photometry and the models of D&#39;Antona & Mazzitelli, we find that the distribu

Mauricio Cataldo, Sergio del Campo

We study in this article a class of homogeneous, but anisotropic cosmological models in which shear viscosity is included. Within the matter content we consider a component (the quintessence component) determined by the barotropic equations of state, $p=αρ$, with $α< 0$. We establish conditions under which a closed axisymmetrical cosmological model may look

Hien D. Tran, M. H. Cohen, M. Villar-Martin

We present imaging and spectro- polarimetric observations of the ultraluminous infrared galaxy IRAS P09104+4109 using the Keck 10-m Telescope. We detect the clear presence of broad Hb, Hg, and MgII 2800 emission lines in the polarized flux spectra of the nucleus and of an extranuclear emission region ~ 4&#34; away, confirming the presence of a hidden central

Guillermo Tenorio-Tagle, Casiana Muñoz-Tuñón, Enrique Pérez, Jesús Maíz-Apellániz

Several facts regarding the structure of NGC 604 are examined here. The three main cavities, produced by the mechanical energy from massive stars which in NGC 604 are spread over a volume of 10$^6$ pc$^3$, are shown here to be undergoing blowout into the halo of M33. High resolution long slit spectroscopy is used to track the impact from massive stars while

Julianne J. Dalcanton, Craig J. Hogan

We explore observed dynamical trends in a wide range of dark matter dominated systems (about seven orders of magnitude in mass) to constrain hypothetical dark matter candidates and scenarios of structure formation. First, we argue that neither generic warm dark matter (collisionless or collisional) nor self-interacting dark matter can be responsible for the

Norbert Zacharias, Marion I. Zacharias, Sean E. Urban, Erik Hoeg

The Tycho-2 Catalogue, released in February 2000, is based on the ESA Hipparcos space mission data and various ground-based catalogs for proper motions. An external comparison of the Tycho-2 astrometry is presented here using the first U.S. Naval Observatory CCD Astrograph Catalog (UCAC1). The UCAC1 data were obtained from observations performed at CTIO betw

J. M. Oliveira, B. H. Foing, J. Th. van Loon

In this contribution we investigate how a disk determines the physical and geometrical properties of the circumstellar environment of the T Tauri SU Aurigae. Our model of the spectral energy distribution of this star includes the central young star, a flat black disk and a diffuse envelope. We also describe the inner interaction region between the disk and t

M. Demianski, R. de Ritis, A. A. Marino, E. Piedipalumbo

We derive and solve exactly the Dyer-Roeder equation in a Friedman-Robertson-Walker cosmological model with non zero cosmological constant. To take into account non homogeneous distribution of matter we use the phenomenological clumpiness parameter. We propose also a general form of an approximate solution which is simple enough to be useful in practical app

J. L. Zdunik

The equation of state of strange matter build of the u,d,s quarks in the framework of the MIT bag model is studied. The scaling relations with bag constant are discussed and applied to the determination of maximum frequency of a particle in stable circular orbit around strange star. The highest QPO frequency of 1.33 kHz observed so far is consistent with the

I. K. Baldry, J. Bland-Hawthorn

We describe and evaluate a new instrument design called a Tunable Echelle Imager (TEI). In this instrument, the output from an imaging Fabry-Perot interferometer is cross-dispersed by a grism in one direction and dispersed by an echelle grating in the perpendicular direction. This forms a mosaic of different narrow-band images of the same field on a detector

Puragra Guhathakurta, David B. Reitzel, Eva K. Grebel

We present Keck 10-meter/LRIS spectra of candidate red giants in the halo of M31, located at a projected radius of R=19kpc on the minor axis. These spectroscopic targets have been selected using a combination of UBRI-based and morphological screening to eliminate background galaxies. Radial velocity measurements are used to separate M31 halo giants from fore

V. Korchagin, N. Kikuchi, S. M. Miyama, N. Orlova

We present an observational and theoretical study of the spiral structure in galaxy NGC 1566. A digitized image of NGC 1566 in I-band was used for measurements of the radial dependence of amplitude variations in the spiral arms. We use the known velocity dispersion in the disk of NGC 1566, together with its rotation curve, to construct linear and 2D nonlinea

Heino Falcke, Christian Henkel, Alison B. Peck, Yoshiaki Hagiwara

We report the detection of a new H_2O megamaser in the Seyfert 2 galaxy Mrk 348 with the MPIfR 100 m telescope in Effelsberg. With an apparent isotropic luminosity of L_H2O ~ 420 L_sun the maser is the third most luminous maser discovered so far. The detected line is unusually broad (Delta v ~ 130 km/s), is redshifted by ~130 km/s from the systemic velocity,

V. V. Sokolov, T. A. Fatkhullin, V. N. Komarova

We present a photometry of GRB 980703 and GRB 990123 host galaxies which was performed about 20 days and a half year after gamma-ray bursts occured, respectively. The contributions of the optical transiets (OT) were negligible in both cases. We derived broad band BVR_cI_c spectra of the host galaxies and compared them to continuum spectra of different Hubble

Wayne H. Lau, J. T. Olesberg, Michael E. Flatte&#39;

A theory for longitudinal (T1) and transverse (T2) electron spin coherence times in zincblende semiconductor quantum wells is developed based on a non-perturbative nanostructure model solved in a fourteen-band restricted basis set. Distinctly different dependences of coherence times on mobility, quantization energy, and temperature are found from previous ca

J. Lopez, P. N. Lisboa-Filho, W. A. C. Passos, W. A. Ortiz

We reported a systematic change in the average magnetic relaxation rate, after the application and removal of a 5 T magnetic field, in a polycrystalline sample of La0.5Ca0.5MnO3. Magnetic relaxation measurements and magnetization versus field curves were taken from 10 K to 160 K. The long time behavior of the relaxation curves was approximately logarithmic i

Xuedong Hu, Rogerio de Sousa, S. Das Sarma

We consider theoretically the interplay between Zeeman coupling and exchange-induced swap action in spin-based quantum dot quantum computer models in the presence of inhomogeneous magnetic fields, which are invariably present in real systems. We estimate quantitatively swap errors caused by the inhomogeneous field, establishing that error correction would, i

Michael C. Liu, Stephane Charlot, James R. Graham

(Abridged) We present new theoretical predictions for surface brightness fluctuations (SBFs) using models optimized for this purpose. Our predictions agree well with SBF data for globular clusters and elliptical galaxies. We provide refined theoretical calibrations and k-corrections needed to use SBFs as standard candles. We suggest that SBF distance measure

M. O. Dzero

We have verified that the variational mean field theory approach suggested by Narimanov and Varma (preprint cond-mat/0002191) being applied to the realistic two-band model provides a good agreement with experimental data for the Curie temperature in doped manganites A$_{1-x}$B$_x$MnO$_3$ ($x\simeq{0.3}$). We have also considered the problem of an interplay b

J. T. Devreese, S. N. Klimin, V. M. Fomin

The absorption of large bipolarons is investigated using the path-integral method. The response of a bipolaron to an external electromagnetic field is derived in the framework of the memory-function approach. The bipolaron optical absorption spectrum consists of a series of relatively narrow peaks. The peculiarities of the bipolaron optical absorption as a f

Chong-Sun Chu, Rodolfo Russo, Stefano Sciuto

The multiloop amplitudes for the bosonic string in presence of a constant B-field are built by using the basic commutation relations for the open string zero modes and oscillators. The open string Green function on the annulus is obtained from the one loop scattering amplitude among N tachyons. For higher loops, it is necessary to use the so called three Reg

K. Hagino, A. Parreno

We discuss the nonmesonic decay of deformed p-shell hypernuclei. The Nilsson model with angular momentum projection is employed in order to take into account the deformation effects. The nonmesonic decay rate and the intrinsic $Λ$ asymmetry parameter decrease as a function of the deformation parameter, while the ratio of the neutron- to proton-induced decay

S. Martinez, F. Pennini, A. Plastino

Tsallis&#39; thermostatistics is by now recognized as a new paradigm for statistical mechanical considerations. However, it is still affected by a serious hindrance: the generalization of thermodynamics&#39; zero-th law to a nonextensive scenario is plagued by difficulties. Here we show how to overcome this problem.

Ian I. Kogan, Martin Schvellinger, Bayram Tekin

We study the Renormalization Group (RG) flow of critical bosonic background fields in the framework of the RG approach to string theory. In this approach quantum field theory beta-functions are the extra inputs in solving the string theory sigma-model equations. We study two different situations, the first one is the Yang-Mills theory where the coupling cons

Mario Einax, Michael Schulz

The d-dimensional n-spin facilitated kinetic Ising model is studied analytically starting from usual master equations and their transformation into a Fock-space representation. The evolution of relevant operators is rewritten in terms of a projection formalism. The obtained frequency matrices and memory terms are analyzed. Especially, the influences of the m

J. Cernicharo, A. Noriega-Crespo, D. Cesarsky, B. Lefloch

The formation and evolution of young low mass stars are characterized by important processes of mass loss and accretion ocurring in the innermost regions of their placentary circumstellar disks. Because of the large obscuration of these disks at optical and infrared wavelengths in the early protostellar stages (Class 0 Sources), they were previously detected

Federico Ricci-Tersenghi, Riccardo Zecchina

We numerically study finite-dimensional spin glasses at low and zero temperature, finding evidences for (i) strong time/space heterogeneities, (ii) spontaneous time scale separation and (iii) power law distributions of flipping times. Using zero temperature dynamics we study blocking, clustering and persistence phenomena.

D. L. Harrison, J. A. Rubino-Martin, S. J. Melhuish, R. A. Watson

This paper presents the results from the Jodrell Bank-IAC two-element 33 GHz interferometer operated with an element separation of 32.9 wavelengths and hence sensitive to 1 deg scale structure on the sky. The level of CMB fluctuations, assuming a flat CMB spatial power spectrum over the range of multipoles l = 208 +- 18, was found using a likelihood analysis

A. V. Belitsky, S. Vandoren, P. van Nieuwenhuizen

In these lectures, which are written at an elementary and pedagogical level, we discuss general aspects of (single) instantons in SU(N_c) Yang-Mills theory, and then specialize to the case of N = 4 supersymmetry and the large N_c limit. We show how to determine the measure of collective coordinates and compute instanton corrections to certain correlation fun

J. Tempere, J. T. Devreese

The optical absorption of a many (continuum) polaron gas is derived in the framework of a variational approach at zero temperature and weak or intermediate electron-phonon coupling strength. We derive a compact formula for the optical conductivity of the many-polaron system taking into account many-body effects in the electron or hole system. Within the meth

Kentaroh Yoshida

We discuss the phase structure of QCD_4 as a perturbative deformation of the Topological Quantum Field Theory (TQFT). When we choose a special Maximal Abelian gauge (MAG) as the gauge fixing, the TQFT sector is equivalent to a 2D O(3) non-linear sigma model (NLSM). We consider the finite temperature case, and investigate the effect of the boundary conditions

J. Tempere, J. T. Devreese

A sum rule for the first frequency moment of the optical absorption of a many-polaron system is derived, taking into account many-body effects in the system of constituent charge carriers of the many-polaron system. In our expression for the sum rule, the electron-phonon coupling and the many-body effects in the electron (or hole) system formally decouple, s

J. A. Sellwood

The central densities of dark matter (DM) halos are much lower than predicted in cold DM models of structure formation. Confirmation that they have cores with a finite central density would allow us to rule out many popular types of collisionless particle as candidates for DM. Any model that leads to cusped halos (such as cold DM) is already facing serious d

G. Brodin, M. Marklund, M. Servin

We consider propagation of gravitational radiation in a magnetized multicomponent plasma. It is shown that large density perturbations can be generated, even for small deviations from flat space, provided the cyclotron frequency is much larger than the plasma frequency. Furthermore, the induced density gradients can generate frequency conversion of electroma

Z. Bajnok, L. Palla, G. Takacs, F. Wagner

We consider the k-folded sine-Gordon model, obtained from the usual version by identifying the scalar field after k periods of the cosine potential. We examine (1) the ground state energy split, (2) the lowest lying multi-particle state spectrum and (3) vacuum expectation values of local fields in finite spatial volume, combining the Truncated Conformal Spac

Madoka Nishimura

Construction of a five dimensional conformal supergravity (D=5 CSG) is attempted by applying the AdS/CFT correspondence to the F(4) AdS supergravity in six dimensions. As a first step, local transformation laws of D=5 CSG have been established, from which the Weyl weights of the various fields in D=5 can be predicted.

David K. Lubensky, David R. Nelson

We study a class of micromanipulation experiments, exemplified by the pulling apart of the two strands of double-stranded DNA (dsDNA). When the pulling force is increased to a critical value, an ``unzipping&#39;&#39; transition occurs. For random DNA sequences with short-ranged correlations, we obtain exact results for the number of monomers liberated and th

Ralf Hofmann

A class of generalized Wess-Zumino models with distinct vacua is investigated. These models allow for BPS saturated vacua interpolation along one compact spatial dimension. The properties of these interpolations are studied.

Juan B. Gil

The operator $e^{-tA}$ and its trace are investigated in the case when $A$ is a non-self-adjoint elliptic differential operator on a manifold with conical singularities. Under a certain spectral condition (parameter-ellipticity) we obtain a full asymptotic expansion in $t$ of the heat trace as $t\to 0^+$. As in the smooth compact case, the problem is reduced

Michael E. Crenshaw, Charles M. Bowden

The local-field renormalization of the spontaneous emission rate in a dielectric is explicitly obtained from a fully microscopic quantum-electrodynamical, many-body derivation of Langevin-Bloch operator equations for two-level atoms embedded in an absorptive and dispersive, linear dielectric host. We find that the dielectric local-field enhancement of the sp

R P Martínez-y-Romero, H N Núñez-Yépez, A L Salas-Brito

Recurrence formulae for arbitrary hydrogenic radial matrix elements are obtained in the Dirac form of relativistic quantum mechanics. Our approach is inspired on the relativistic extension of the second hypervirial method that has been succesfully employed to deduce an analogous relationship in non relativistic quantum mechanics. We obtain first the relativi

Eduard Schmidt, Ludwig Knoll, Dirk-Gunnar Welsch

It is shown that bipartition of optical solitons can be used to generate entangled light beams. The achievable amount of entanglement can be substantially larger for N-bound solitons N=2,3 than for the fundamental soliton (N=1). An analysis of the mode structure of the entangled beams shows that just N modes are essentially entangled. In particular, partitio

Yu. A. Baurov, G. A. Beda, I. P. Danilenko, V. P. Ignatko

An experimental investigation of a new interaction connected with the existence of the cosmological vectorial potential, has been carried out. On its basis, a new method of energy generation with the use of a plasma generator, has been studied. The experimental results and complete analysis of errors in the experiments are presented.

B. G. Sidharth

We discuss briefly discrete space effects and show that this leads to space reflection asymmetry and also a minor modification of Einstein&#39;s energy-mass formula.

S. Banerjee, D. Mathur, G. Ravindra Kumar

The propensity of molecules to spatially align along the polarization vector of intense, pulsed light fields is related to readily-accessible parameters (molecular polarizabilities, moment of inertia, peak intensity of the light and its pulse duration). Predictions can now be made of which molecules can be spatially aligned, and under what circumstances, upo

D. A. Varshalovich, A. Y. Potekhin, A. V. Ivanchik

We discuss experiments and observations aimed at testing the possible space-time variability of fundamental physical constants, predicted by the modern theory. Specifically, we consider two of the dimensionless physical parameters which are important for atomic and molecular physics: the fine-structure constant and the electron-to-proton mass ratio. We revie

B. G. Sidharth

We point out that the observed decay mode of the pion and the Kaon decay puzzle are really imprints of discrete micro space-time.

K. A. Bugaev, M. I. Gorenstein, H. Stöcker, and W. Greiner

Conventional cluster and virial expansions are generalized to momentum dependent inter-particle potentials. The model with Lorentz contracted hard core potentials is considered, e.g. as hadron gas model. A Van der Waals-type model with a temperature dependent excluded volume is derived. Lorentz contraction effects at given temperature are stronger for light

Daniel R. Phillips

I provide a brief, and therefore necessarily biased, review of the application of effective field theory to electromagnetic processes on the deuteron. Electron-deuteron scattering is discussed for virtual photon momenta up to 700 MeV, and photon-deuteron scattering is examined for incident photon energies of order the pion mass.

P. Navratil, J. P. Vary, B. R. Barrett

We obtain properties of $^{12}$C in the {\it ab initio} no-core nuclear shell-model. The effective Hamiltonians are derived microscopically from the realistic CD-Bonn and the Argonne V8&#39; nucleon-nucleon (NN) potentials as a function of the finite harmonic oscillator basis space. Binding energies, excitation spectra and electromagnetic properties are pres

I. Fachruddin, Ch. Elster, W. Glöckle

The nucleon-nucleon (NN) t-matrix is calculated directly as function of two vector momenta for different realistic NN potentials. To facilitate this a formalism is developed for solving the two-nucleon Lippmann-Schwinger equation in momentum space without employing a partial wave decomposition. The total spin is treated in a helicity representation. Two diff

Vyacheslav V. Stepanov, Gerhard Muller

For a (classically) integrable quantum mechanical system with two degrees of freedom, the functional dependence $\hat{H}=H_Q(\hat{J}_1,\hat{J}_2)$ of the Hamiltonian operator on the action operators is analyzed and compared with the corresponding functional relationship $H(p_1,q_1;p_2,q_2) = H_C(J_1,J_2)$ in the classical limit of that system. The former is

Debabrata Biswas, B. A. R. C, Mumbai, India

Intermittent or marginally-stable repellers are commonly associated with a power law decay in the survival fraction. We show here that the presence of weak additive noise alters the spectrum of the Perron - Frobenius operator significantly giving rise to exponential decays even in systems that are otherwise regular. Implications for ballistic transport in ma

R. Kerner

We present a short introductory overview of the non-commutative extensions of several classical physical theories. After a general discussion of the reasons that suggest that the non-commutativity is a major issue that will eventually lead to the unification of gravity with other fundamental interactions, we display examples of non-commutative generalization

R. Kerner

We present a possible generalization of the exterior differential calculus, based on the operator d such that d^3=0, but d^2\not=0. The first and second order differentials generate an associative algebra; we shall suppose that there are no binary relations between first order differentials, while the ternary products will satisfy the cyclic relations based

R. Kerner

We present a survey of recent results, scattered in a series of papers that appeared during past five years, whose common denominator is the use of cubic relations in various algebraic structures. Cubic (or ternary) relations can represent different symmetries with respect to the permutation group S_3, or its cyclic subgroup Z_3. Also ordinary or ternary alg