March 2001 arXiv papers — page 19

E. Brezin, S. Hikami

It is shown that the correlation functions of the random variables $\det(λ- X)$, in which $X$ is a real symmetric $ N\times N$ random matrix, exhibit universal local statistics in the large $N$ limit. The derivation relies on an exact dual representation of the problem: the $k$-point functions are expressed in terms of finite integrals over (quaternionic) $k

A. Chakrabarti

General solutions of the $\hat{R}TT$ equation with a maximal number of free parameters in the specrtal decomposition of vector $SO_q (3)$ $\hat{R}$ matrices are implemented to construct modified braid equations (MBE). These matrices conserve the given, standard, group relations of the nine elements of T, but are not constrained to satisfy the standard braid

Marcos Marino

We propose a Batalin-Vilkovisky (BV) formulation of boundary superstring field theory. The superstring field action is defined in terms of a closed one-form in the space of couplings, and we compute it explicitly for exactly solvable tachyon perturbations. We also argue that the superstring field action defined in this way is the partition function on the di

R. R. Metsaev

Massive arbitrary spin fields in AdS(3) spacetime are discussed in a framework of light-cone gauge formulation. We also consider compactification of AdS spacetime on manifold which is warped product of AdS space and sphere. Mass spectra of massless and massive fields upon such compactification are found.

Massimo Blasone, Petr Jizba, Giuseppe Vitiello

We present an analysis of currents and charges for a system of two mixed fields, both for spinless bosons and for Dirac fermions. This allows us to obtain in a straightforward way the exact field theoretical oscillation formulas exhibiting corrections with respect to the usual ones derived in quantum mechanics.

C. Albertsson, B. Brinne, U. Lindstrom, M. Rocek

We show that the Higgs branch of a four-dimensional Yang-Mills theory, with gauge and matter content summarised by an ADE quiver diagram, is identical to the generalised Coulomb branch of a four-dimensional superconformal strongly coupled gauge theory with ADE global symmetry. This equivalence suggests the existence of a mirror symmetry between the quiver th

Zygmunt Lalak

We present the explicit form of the four-dimensional effective supergravity action which describes low-energy physics of the Randall--Sundrum model with moduli fields in the bulk and charged chiral matter living on the branes. The low-energy action is derived from the compactification of a locally supersymmetric model in five dimension. We describe the mecha

Dan Radu Grigore

We consider the gauge invariance of the standard Yang-Mills model in the framework of the causal approach of Epstein-Glaser and Scharf and determine the generic form of the anomalies. The method used is based Epstein-Glaser approach to renormalization theory. In the case of quantum electrodynamics we obtain quite easily the absence of anomalies in all orders

W. L. van Neerven, A. Vogt

We study the evolution of the flavour non-singlet deep-inelastic structure functions F_{2,NS} and F_3 at the next-to-next-to-next-to-leading order (N^3LO) of massless perturbative QCD. The present information on the corresponding three-loop coefficient functions is used to derive approximate expressions of these quantities which prove completely sufficient f

Robert Fleischer, Thomas Mannel

Employing the SU(2) isospin symmetry of strong interactions and estimates borrowed from effective field theory, we explore the impact of new physics on the decays $B^\pm\to ϕK^\pm$ and $B_d\to ϕK_S$ in a model-independent manner. To this end, we introduce - in addition to the usual mixing-induced CP asymmetry in $B_d\to ϕK_S$ - a set of three observables, wh

A. G. Akeroyd, Y. -Y. Keum, S. Recksiegel

We investigate the effect of supersymmetric CP violating phases on the inclusive decay B\to X_dγ. Although such a decay contains a large background from B\to X_sγ, if isolated it may exhibit sizeable CP violation, both in the Standard Model (SM) and in the context of models beyond the SM. With unconstrained supersymmetric CP violating phases we show that the

The DELPHI Collaboration, P. Abreu

Searches for pair production of gauginos and squarks in e+e- collisions at a centre-of-mass energy of 189 GeV have been performed on data corresponding to an integrated luminosity of 158 pb^{-1} collected by the DELPHI detector at LEP. The data were analyzed under the assumption of non-conservation of R-parity through a single dominant Ubar Dbar Dbar couplin

The DELPHI Collaboration, P. Abreu

Searches for charginos, neutralinos and sleptons at LEP2 centre-of-mass energies from 130 GeV to 189 GeV have been used to set lower limits on the mass of the Lightest Supersymmetric Particle and other supersymmetric particles within the MSSM framework. R-parity conservation has been assumed. The lightest neutralino was found to be heavier than 32.3 GeV/c^2

The DELPHI Collaboration, P. Abreu

The cross-section for the process e+e- -> W+W- has been measured with the data sample collected by DELPHI at an average centre-of-mass energy of 189 GeV and corresponding to an integrated luminosity of 155 pb^{-1}. Based on the 2392 events selected as WW candidates, the cross-section for the doubly resonant process e+e- -> W+W- has been measured to be 15.83

Esteban Calzetta, Albert Roura, Enric Verdaguer

The master equation for a linear open quantum system in a general environment is derived using a stochastic approach. This is an alternative derivation to that of Hu, Paz and Zhang, which was based on the direct computation of path integrals, or to that of Halliwell and Yu, based on the evolution of the Wigner function for a linear closed quantum system. We

Clifford M. Will

The status of experimental tests of general relativity and of theoretical frameworks for analysing them are reviewed. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP and of the inverse square law will search f

M. Gasperini, C. Ungarelli

We discuss the possible detection of a stochastic background of massive, non-relativistic scalar particles, through the cross correlation of the two LIGO interferometers in the initial, enhanced and advanced configuration. If the frequency corresponding to the mass of the scalar field lies in the detector sensitivity band, and the non-relativistic branch of

Banibrata Mukhopadhyay

We study the behaviour of spin-half particles in curved space-time. Since Dirac equation gives the dynamics of spin-half particles, we mainly study the Dirac equation in Schwarzschild, Kerr, Reissner-Nordström geometry. Due to the consideration of existence of black hole in space-time (the curved space-time), particles are influenced and equation will be mod

Raymond Y. Chiao, Jandir M. Hickmann, Daniel Solli

Recent manifestations of apparently faster-than-light effects confirmed our predictions that the group velocity in transparent optical media can exceed c. Special relativity is not violated by these phenomena. Moreover, in the electronic domain, the causality principle does not forbid negative group delays of analytic signals in electronic circuits, in which

Masaki Murata, Masao Utiyama, Qing Ma, Hiromi Ozaku

We have developed systems of two types for NTCIR2. One is an enhenced version of the system we developed for NTCIR1 and IREX. It submitted retrieval results for JJ and CC tasks. A variety of parameters were tried with the system. It used such characteristics of newspapers as locational information in the CC tasks. The system got good results for both of the

Masaki Murata, Kyoko Kanzaki, Kiyotaka Uchimoto, Qing Ma

It is often useful to sort words into an order that reflects relations among their meanings as obtained by using a thesaurus. In this paper, we introduce a method of arranging words semantically by using several types of `{\sf is-a}' thesauri and a multi-dimensional thesaurus. We also describe three major applications where a meaning sort is useful and s

Masaki Murata, Kiyotaka Uchimoto, Qing Ma, Hitoshi Isahara

The referential properties of noun phrases in the Japanese language, which has no articles, are useful for article generation in Japanese-English machine translation and for anaphora resolution in Japanese noun phrases. They are generally classified as generic noun phrases, definite noun phrases, and indefinite noun phrases. In the previous work, referential

Masaki Murata, Kiyotaka Uchimoto, Qing Ma, Hitoshi Isahara

George A. Miller said that human beings have only seven chunks in short-term memory, plus or minus two. We counted the number of bunsetsus (phrases) whose modifiees are undetermined in each step of an analysis of the dependency structure of Japanese sentences, and which therefore must be stored in short-term memory. The number was roughly less than nine, the

V. S. Boyko, A. M. Levine

We present the results of a computer simulation of the atomic structures of large-angle symmetrical tilt grain boundaries (GBs) $Σ5$ (misorientation angles $\q{36.87}{^{\circ}}$ and $\q{53.13}{^{\circ}}$), $Σ13$ (misorientation angles $\q{22.62}{^{\circ}}$ and $\q{67.38}{^{\circ}}$). The critical strain level $ε_{crit}$ criterion (phenomenological criterion)

Sudeshna DasGupta, Soumen Kumar Roy

The effect of a rigid, non-polar and nonmesogenic solute biphenyl ((C_{6}H_{5}-C_{6}H_{5})) on the divergence of the bend elastic constant K_{33} of (4,4^{\prime}) -n-octyl-cyanobiphenyl (8CB) near the smecticA-nematic transition is reported. The exponent decreases from about 1.0 to 0.67 as the concentration of biphenyl increases. The temperature at which th

P. Jefferies, M. L. Hart, N. F. Johnson

The Minority Game (MG) behaves as a stochastically perturbed deterministic system due to the coin-toss invoked to resolve tied strategies. Averaging over this stochasticity yields a description of the MG's deterministic dynamics via mapping equations for the strategy score and global information. The strategy-score map contains both restoring-force and b

Rafal Weron, B. Kozlowska, J. Nowicka-Zagrajek

In this paper we address the issue of modeling electricity loads and prices with diffusion processes. More specifically, we study models which belong to the class of generalized Ornstein-Uhlenbeck processes. After comparing properties of simulated paths with those of deseasonalized data from the California power market and performing out-of-sample forecasts

Rafal Weron

Power-law tail behavior and the summation scheme of Levy-stable distributions is the basis for their frequent use as models when fat tails above a Gaussian distribution are observed. However, recent studies suggest that financial asset returns exhibit tail exponents well above the Levy-stable regime ($0<α\le 2$). In this paper we illustrate that widely used

J. Zaanen

This piece has been written for local, educational purposes. If you are like me searching for the right words to explain your fascination with high Tc superconductivity to the outside world, you might find something useful in this text.

R. Schiller, W. Nolting

We calculate the temperature and layer-dependent electronic structure of a 20-layer EuO(100)-film using a combination of first-principles and model calculation based on the ferromagnetic Kondo-lattice model. The results suggest the existence of a EuO(100) surface state which can lead to a surface insulator-metal transition.

S. I. Mukhin, W. van Saarloos, J. Zaanen

The finite temperature physics of the gas of elastic quantum strings as introduced in J. Zaanen, Phys. Rev. Lett. 84, 753 is investigated. This model is inspired on the stripes in the high Tc superconductors. We analyze in detail how the kinetic interactions of the zero temperature quantum problem crossover into the entropic interactions of the high temperat

R. Schiller, W. Nolting

We present calculations for the temperature-dependent electronic structure of bulk ferromagnetic EuO based on a parametrization of the d-f model Hamiltonian using results of first-principles TB-LMTO band structure calculations. The presented method avoids the problem of double-counting of relevant interactions and takes into account the symmetry of the atomi

B. Paredes, P. Fedichev, J. I. Cirac, P. Zoller

We discuss a way of creating, manipulating and detecting anyons in rotating Bose-Einstein condensates consisting of a small number of atoms . By achieving a quasidegeneracy in the atomic motional states we drive the system into a 1/2--Laughlin state for fractional quantum Hall bosons. Localized 1/2--quasiholes can be created by focusing lasers at the desired

Yuriy I. Kuzmin

The effect of geometry and morphology of superconducting structure on magnetic flux trapping is considered. It is found that the clusters of normal phase, which act as pinning centers, have significant fractal properties. The fractal dimension of the boundary of these clusters is estimated using a simple area-perimeter relation. A superconductor is treated a

N. B. Wilding

The task of accurately locating fluid phase boundaries by means of computer simulation is hampered by problems associated with sampling both coexisting phases in a single simulation run. We explain the physical background to these problems and describe how they can be tackled using a synthesis of biased Monte Carlo sampling and histogram extrapolation method

Maleki-Jirsaraei, B. Ghane-Motlagh, S. Baradaran, E. Shekarian

Patterns formed by the flow of an inhomogeneous fluid (suspension) over a smooth inclined surface were studied. It was observed that for inclination angle larger than a threshold, global fractal patterns are formed. The fractal dimensions of these patterns were measured df=1.35-1.45 which corresponds to that observed for the flow of water over an inhomogeneo

Parongama Sen

We consider a model in which the quantum fluctuation can be controlled and show that the system responds to a spatially periodic external field at zero temperature. This signifies the occurrence of spatial stochastic resonance where the fluctuations are purely quantum in nature. Various features of the phenomenon are discussed.

Bikash C. Gupta, Sang Bub Lee

Formation of stationary localized states in one-dimensional chain as well as in a Cayley tree due to a linear impurity and a nonlinear impurity is studied. Furthermore, a one-dimensional chain with linear and nonlinear site energies at the alternate sites is studied and rich phase diagrams of SL states are obtained for all systems we considered. The results

T. Takenobu, T. Ito, Dam H. Chi, K. Prassides

We report that the ternary MgB2-xCx compounds adopt an isostructural AlB2-type hexagonal structure in a relatively small range of nominal carbon concentration, x<0.1. The lattice parameter a decreases almost linearly with increasing carbon content x, while the c parameter remains unchanged, indicating that carbon is exclusively substituted in the boron honey

J. J. McGuire, T. Room, A. Pronin, T. Timusk

The interplane optical spectrum of the organic superconductor kappa-(BEDT-TTF)2Cu[N(CN)2]Br was investigated in the frequency range from 40 to 40,000 cm-1. The optical conductivity was obtained by Kramers-Kronig analysis of the reflectance. The absence of a Drude peak at low frequency is consistent with incoherent conductivity but in apparent contradiction t

A. Mishchenko, N. V. Prokof&#39;ev, B. V. Svistunov

Worm algorithm quantum Monte Carlo simulations of the hole Green function with subsequent spectral analysis were performed for J/t 0.1, 0.2, 0.4 on lattices with up to LxL=32x32 sites at temperatures as low as T=J/40, and present, apparently, the hole spectral function in the thermodynamic limit. Spectral analysis reveals a delta-function-sharp quasiparticle

W. Kuo

This paper has been withdrawn by the authors due to new experimental results.

N. A. Tomimura, M. de Campos

Perturbations in Prigogine&#39;s cosmological model with particle creation are investigated in the framework of Newtonian Theory. The necessary conditions for the density contrast to reach the non-linear regime wich is necessary to garantee structure formation at large scale are obtained. The upper limit of the age of the universe is investigated for the per

M. de Campos, N. A. Tomimura

A new equation for the density contrast is derived in the framework of reexamined Newtonian cosmology taken into account adiabatic matter creation in the universe. The age of the universe and the reach of the non linear regime of the density contrast are usually treated separately in the literature and this may lead to controversial conclusions regarding the

Hong Lin Zhang, Sultana N. Nahar, Anil K. Pradhan

Relativistic and channel coupling effects in photoionization and unified electronic recombination of Fe XVII are demonstrated with an extensive 60-level close coupling calculation using the Breit-Pauli R-matrix method. Photoionization and (e + ion) recombination calculations are carried out for the total and the level-specific cross sections, including the g

M. J. Richter, J. H. Lacy, D. T. Jaffe, T. K. Greathouse

We broadly discuss mid-infrared spectroscopy and detail our new high spectral resolution instrument, the Texas Echelon-cross-Echelle Spectrograph (TEXES).

Dragan Huterer, Michael S. Turner

The presence of dark energy in the Universe is inferred directly from the accelerated expansion of the Universe, and indirectly, from measurements of cosmic microwave background (CMB) anisotropy. Dark energy contributes about 2/3 of the critical density, is very smoothly distributed, and has large negative pressure. Its nature is very much unknown. Most of i

Paulo J. V. Garcia, Sylvie Cabrit, Jonathan Ferreira, Fabien Casse

We summarize results on the thermal and ionization structure of self-similar, magnetically-driven, atomic disk winds heated by ambipolar diffusion. We improve upon earlier work by Safier by considering (1) new MHD solutions consistent with underlying cold keplerian disk equilibrium, (2) a more accurate treatment of the micro-physics, and (3) predictions for

P. S. Corasaniti, L. Amendola, F. Occhionero

The analysis of the CMB anisotropies is a rich source of cosmological informations. In our study, we simulated the signals produced by the relics of a first order phase transition occured during an inflationary epoch in the early Universe. These relics are bubbles of true vacuum that leave a characteristic non-Gaussian imprint on the CMB. We use different st

Daniel E. Welty, Edward L. Fitzpatrick

Within the last 10 years, strong, narrow Na I absorption has appeared at v_sun ~ -38 km/s toward the halo star HD 219188; that absorption has continued to strengthen, by a factor 2-3, over the past three years. The line of sight appears to be moving into/through a relatively cold, quiescent intermediate velocity (IV) cloud, due to the 13 mas/yr proper motion

G. G. Pavlov, V. E Zavlin, D. Sanwal, V. Burwitz

We report the results of the spectral analysis of two observations of the Vela pulsar with the Chandra X-ray observatory. The spectrum of the pulsar does not show statistically significant spectral lines in the observed 0.25-8.0 keV band. Similar to middle-aged pulsars with detected thermal emission, the spectrum consists of two distinct components. The soft

A. Vidal-Madjar

Primordial evaluations of the deuterium abundance should provide one of the best tests of Big Bang nucleosynthesis models. Space as well as ground based observations seem however to result in different values. This asks for more observations in different astrophysical sites in order to link present day interstellar medium D/H evaluations to primordial ones.

Jacques Paul, Michel Casse, Elisabeth Vangioni-Flam

We briefly review the fundamentals of nuclear gamma-ray line astronomy (radioactive astronomy), focusing on its role to decipher the intimate physics of supernovae, either immediatly (via $^{56}Co)$ or after a time delay (via $^{44}Ti$). All kinds of supernovae can be in principle tested through their radioactivities and their associated gamma-ray lines. Ded

M. Ostrowski, M. Sikora

Recently Hardcastle & Worrall (MNRAS, 319, 562) analyzed 63 FRII radio galaxies imbedded in the X-ray radiating gas in galaxy clusters and concluded, that pressures inside its lobes seem to be a factor of a few lower than in the surrounding gas. One of explanations of the existing `blown up&#39; radio lobes is the existence of invisible internal pressure com

A. Bressan, B. Poggianti, A. Franceschini

Among star forming galaxies, a spectral combination of a strong Hdelta line in absorption and a moderate [OII] emission has been suggested to be a useful method to identify dusty starburst galaxies at any redshift, on the basis of optical data alone. On one side it has been shown that such a spectral particularity is indeed suggestive of obscured starburst g

Emmi Meyer-Hofmeister, Friedrich Meyer

The outburst cycles of black hole X-ray transients are now generally understood as caused by a thermal instability in the accretion disk, the same mechanism as in dwarf novae outbursts. During quiescence the accretion occurs via a cool disk in the outer region but changes to a coronal flow/ADAF in the inner region. The transition to the coronal flow is cause

Guillermo Gonzalez, Donald Brownlee, Peter Ward

We propose the concept of a &#34;Galactic Habitable Zone&#34; (GHZ). Analogous to the Circumstellar Habitable Zone (CHZ), the GHZ is that region in the Milky Way where an Earth-like planet can retain liquid water on its surface and provide a long-term habitat for animal-like aerobic life. In this paper we examine the dependence of the GHZ on Galactic chemica

Kiran Jain, S. C. Tripathy, A. Bhatnagar

We present results on variation in rotation rate in the upper convection zone using data from GONG and MDI/SOHO covering a period of more than four years. We find that the first few odd-order splitting coefficients vary systematically with the solar cycle. The rotation rate near the solar surface calculated from analytical methods agrees well with that of in

Kiran Jain, S. C. Tripathy, A. Bhatnagar

We have analysed temporal evolution in centroid frequencies and splitting coefficients of solar f-modes obtained from MDI/SOHO. The data were divided into 20 sets covering a period from May 1, 1996 to August 31, 2000. The variation in frequencies is estimated to be 68 nHz over the period of four years which includes the rapidly rising phase of the solar cycl

Banibrata Mukhopadhyay

We study the nucleosynthesis in accretion disk around compact object. When matter falls towards the compact object, due to interactions in nuclear species nuclear energy is released in the high temperature. In some region of parameter space nuclear energy becomes comparable or higher to the energy release due to the viscous effect of the disk. In those regio

Carlos Nunez, I. Y. Park, Martin Schvellinger, Tuan A. Tran

We construct supergravity solutions dual to twisted field theories that are the worldvolume theories of D4-branes wrapped on 2, 3-cycles, and NS-fivebranes on 3-cycles. We first obtain the solutions for the Romans' six-dimensional gauged supergravity theories and then up-lift them to ten dimensions. In particular, we find solutions for field configurations w

M. G. Santos, F. Vernizzi, P. G. Ferreira

We reexamine Wald&#39;s no-hair theorem for global anisotropy in the brane world scenarios. We derive a set of sufficient conditions which must be satisfied by the brane matter and bulk metric so that a homogeneous and anisotropic brane asymptotically evolves to a de Sitter spacetime in the presence of a positive cosmological constant on the brane. We discus

A. N. Mitra, B. M. Sodermark

The half-century old Markov-Yukawa Transversality Principle ($MYTP$) which provides a theoretical rationale for the covariant instantaneous approximation ($CIA$) that underlies all Salpeter-like equations, is generalized to a covariant null-plane ansatz ($CNPA$). A common characteristic of both formulations is an exact 3D-4D interlinkage of BS amplitudes whi

P. -H. Chavanis

We investigate the stability of bounded self-gravitating systems in the canonical ensemble by using a thermodynamical approach. Our study extends the earlier work of Padmanabhan [Astrophys. J. Supp. 71, 651 (1989)] in the microcanonical ensemble. By studying the second variations of the free energy, we find that instability sets in precisely at the point of

J. Chee

For a spin subjected to an adiabatically changing magnetic field, the solid angle result as embodied by a rotation operator is the only path-dependent factor in the quantum evolution operator. For a charged particle, the infinite degeneracy calls for a rigorous investigation. We find that in this case, it is the product of the rotation operator and a path-or

Shin&#39;ichi Nojiri, Sergei D. Odintsov

It is shown that quantum-induced (inflationary) brane Universe occurs in the bulk 5d AdS black hole in accordance with AdS/CFT correspondence. Brane stress tensor is induced by quantum effects of dual CFT and brane crosses the horizon of AdS black hole. Quantum-corrected Hubble constant, Hawking temperature and entropy are found on the brane (and at the hori

Kaiki Taro Inoue

We study the effect of global topology of the spatial geometry on the cosmic microwave background (CMB) for closed flat and closed hyperbolic models in which the spatial hypersurface is multiply connected. If the CMB temperature fluctuations were entirely produced at the last scattering, then the large-angle fluctuations would be much suppressed in compariso

Zeng-Bing Chen, Jian-Wei Pan, Guang Hou, Yong-De Zhang

We generalize Bell&#39;s inequalities to biparty systems with continuous quantum variables. This is achieved by introducing the Bell operator in perfect analogy to the usual spin-1/2 systems. It is then demonstrated that two-mode squeezed vacuum states display quantum nonlocality by using the generalized Bell operator. In particular, the original Einstein-Po

Kinwah Wu

The observed luminosity distributions of X-ray sources indicate the presence of several populations of X-ray binaries in the nearby galaxies. Each population has its formation and evolutionary history, depending on the host environment. The features seen in the log N($>$S) -- log S curves for different types of galaxies and for different galactic components

Marcelo Schiffer

In this paper we put forward a mechanism in which imploding shock waves emit electromagnetic radiation in the spectral region $λ_{0}\cong 2πR_{0}.$, where R$_{0}$ is the radius of the shock by the time it is first formed. The mechanism relies on three different pieces of Physics: Maxwell&#39;s equations, the existence of corrugation instabilities of implodin

I. O. Rasskazov

The Cauchy problem is considered for the perturbed strictly hyperbolic 2x2 system of quasilinear equations. The unperturbed problem has a persistent solution with two discontinuity lines (shock waves). Both an asymptotics of shock waves position in the plane (x,t) and an asymptotics of the perturbed problem solution are discussed.

J. Kluson

In this paper we extend our previous work hep-th/0102063 to the case D0-brane+antibrane system.

The OPAL collaboration, G. Abbiendi

Using about 3.9 million hadronic Z decays from e+e- collisions recorded by the OPAL detector at LEP at centre-of-mass energies near MZ the branching ratio for the decay D_s -> tau nu_tau has been measured to be (7.0 +/- 2.1(stat) +/- 2.0 (syst))%. This result can be used to derive the decay constant of the D_s meson: f(D_s) = 286 +/- 44(stat) +/- 41(syst) Me

V. V. Ryazanov, V. A. Oboznov, A. V. Veretennikov, A. Yu. Rusanov

We report a direct observation of the crossover of the superconductor- ferromagnet-superconductor (SFS) junctions to the π-state which manifests itself in the half-period shift of the external magnetic field dependence of the transport critical current in the triangular SFS arrays. It is associated with the appearance of spontaneous supercurrents in the arra

Alexandros Pertsinidis, X. S. Ling

We report the first study of the dynamics of point defects, mono and di-vacancies, in a confined 2-D colloidal crystal in real space and time using digital video microscopy. The defects are introduced by manipulating individual particles with optical tweezers. The diffusion rates are measured to be $D_{mono}/a^{2}\cong3.27\pm0.03$Hz for mono-vacancies and $D

Alan Race, W. Barford, Robert J. Bursill

The Pariser-Parr-Pople Hamiltonian is used to calculate and identify the nature of the low-lying vertical transition energies of polydiacetylene. The model is solved using the density matrix renormalisation group method for a fixed acetylenic geometry for chains of up to 102 atoms. The non-linear optical properties of polydiacetylene are considered, which ar

A. E. Meyerovich, I. V. Ponomarev

A new type of quantum size effect (QSE) oscillations is predicted for films with a relatively large correlation radius of surface inhomogeneities. The effect replaces usual QSE for random inhomogeneities with Gaussian and exponential power spectra. The well-pronounced oscillations of conductivity $σ$ as a function of channel width $L$ separate two distinct r

A. K. Zvezdin

Quantum dynamics of anisotropic spin system with large spin moment in a swept magnetic field is theoretically investigated. Magnetic field of this type induces vortex static electrical field, that breaks down the axial symmetry and induces new coherent quantum phenomena: the occurrence of band energy spectrum with continuous spin states, Bloch-type oscillati

W. Bednarek, R. J. Protheroe

We consider the galactic population of gamma-ray pulsars as possible sources of cosmic rays at and just above the ``knee&#39;&#39; in the observed cosmic ray spectrum at $10^{15}$--$10^{16}$ eV. We suggest that iron nuclei may be accelerated in the outer gaps of pulsars, and then suffer partial photo-disintegration in the non-thermal radiation fields of the

W. Belzig, Yu. V. Nazarov

We study the current statistics in normal diffusive conductors in contact with a superconductor. Using an extension of the Keldysh Green&#39;s function method we are able to find the full distribution of charge transfers for all temperatures and voltages. For the non-Gaussian regime, we show that the equilibrium current fluctuations are enhanced by the prese

Wojciech Broniowski, Wojciech Florkowski, Brigitte Hiller

We calculate the medium modifications of the rho pi pi vertex in a relativistic hadronic framework, incorporating nucleons and Delta(1232) isobars. We find a substantial increase of the rho pi pi coupling, dominated by processes where the Delta is excited. The coupling depends significantly on the virtuality of the rho, which is related to analytic propertie

A. Flachi, D. J. Toms

We examine the lowest order quantum corrections to the effective action arising from a quantized real scalar field in the Randall-Sundrum background spacetime. The leading term is the familiar vacuum, or Casimir, energy density. The next term represents an induced gravity term that can renormalize the 4-dimensional Newtonian gravitational constant. The calcu

Kentaroh Yoshida, Wataru Souma

We discuss the phase structure of the four-dimensional compact U(1) gauge theory at finite temperature using a deformation of the topological model. Its phase structure can be determined by the behavior of the Coulomb gas (CG) system on the cylinder. We utilize the relation between the CG system and the sine-Gordon (SG) model, and investigate the phase struc

R. Contino, L. Pilo, R. Rattazzi, A. Strumia

We discuss how to consistently perform effective Lagrangian computations in quantum gravity with branes in compact extra dimensions. A reparametrization invariant and infrared finite result is obtained in a non trivial way. It is crucial to properly account for brane fluctuations and to correctly identify physical observables. Our results correct some confus

Kazuo Ghoroku, Akihiro Nakamura

We address the behaviour of the scalar field with negative mass squared in the five dimensional AdS space where the Randall-Sundrum brane-world is embedded. We point out that the tachyonic scalar allowed in the bulk space destabilizes the embedded brane-world where the cosmological constant is zero. The resolution of this instability is discussed from the vi

G. V. Efimov, G. Ganbold

A simple relativistic quantum field model with the Yukawa-type interaction is considered to demonstrate that the analytic confinement of the constituent (&#34;quarks&#34;) and carrier (&#34;gluons&#34;) particles explains qualitatively the basic dynamical properties of the spectrum of mesons considered as two-particle stable bound states of quarks and gluons

J. Emerson, L. E. Ballentine

We consider the quantum and classical Liouville dynamics of a non-integrable model of two coupled spins. Initially localised quantum states spread exponentially to the system dimension when the classical dynamics are chaotic. The long-time behaviour of the quantum probability distributions and, in particular, the parameter-dependent rates of relaxation to th

V. V. Klimov

The influence of a microsphere having a simultaneously negative permittivity and permeability (Left-Handed Sphere) on the decay rate of the allowed and forbidden transitions is considered. It is found, that in contrast to usual (Right-Handed) materials it is possible to increase the decay rate by several orders of magnitude even in the case of a sphere of sm

Bailin Hao, Huimin Xie, Shuyu Zhang

An amino acid sequence of a protein may be decomposed into consecutive overlapping strings of length K. How unique is the converse, i.e., reconstruction of amino acid sequences using the set of K-strings obtained in the decomposition? This problem may be transformed into the problem of counting the number of Eulerian loops in an Euler graph, though the well-

Ulrich A. Eichmann

The qualitative difference in the use of retarded and Feynman amplitudes as demonstrated in nucl-th/0101024 had been wrongly considered in this comment. The concept of the breakdown of crossing symmetry is not effective in the case considered in the adressed article. The technical aspects of the evaluation of higher-order corrections which were adressed in t

P. P. Kulish, N. Manojlovic

Gaudin model based on the orthosymplectic Lie superalgebra osp(1|2) is studied. The eigenvectors of the osp(1|2) invariant Gaudin hamiltonians are constructed by algebraic Bethe Ansatz. Corresponding creation operators are defined by a recurrence relation. Furthermore, explicit solution to this recurrence relation is found. The action of the creation operato

Oleg Shvedov

The problem of specification of self-adjoint operators corresponding to singular bilinear forms is very important for applications, such as quantum field theory and theory of partial differential equations with coefficient functions being distributions. In particular, the formal expression $-Δ+ gδ({\bold x})$ corresponds to a non-trivial self-adjoint operato

B. Botvinnik, V. Buchstaber, S. Novikov, S. Yuzvinsky

We address the general classification problem of all stable associative product structures in the complex cobordism theory. We show how to reduce this problem to the algebraic one in terms of the Hopf algebra $S$ (the Landweber-Novikov algebra) acting on its dual Hopf algebra $S^*$ with a distinguished ``topologically integral&#39;&#39; part $Λ$ that coincid

Massimiliano Berti, Philippe Bolle

We consider the problem of Arnold Diffusion for nearly integrable partially isochronous Hamiltonian systems with three time scales. By means of a careful shadowing analysis, based on a variational technique, we prove that, along special directions, Arnold diffusion takes place with fast (polynomial) speed, even though the ``splitting determinant&#39;&#39; is

William H. Rowan

Let A be an algebra in a variety V. We study the modulization of a pointed A-overalgebra P, show that it is totally in any variety that P is totally in, and apply this theory to the construction of the enveloping ringoid Z[A,V].

Oleg Shvedov

Semiclassical Hamiltonian field theory is investigated from the axiomatic point of view. A notion of a semiclassical state is introduced. An &#34;elementary&#34; semiclassical state is specified by a set of classical field configuration and quantum state in this external field. &#34;Composed&#34; semiclassical states viewed as formal superpositions of &#34;e

Agapitos Hatzinikitas, Ioannis Smyrnakis

The noncommutative harmonic oscillator in arbitrary dimension is examined. It is shown that the $\star$-genvalue problem can be decomposed into separate harmonic oscillator equations for each dimension. The noncommutative plane is investigated in greater detail. The constraints for rotationally symmetric solutions and the corresponding two-dimensional harmon

Agapitos Hatzinikitas, Renato Portugal

We calculate the integrated trace anomaly for a real spin-0 scalar field in six dimensions in a torsionless curved space without a boundary. We use a path integral approach for a corresponding supersymmetric quantum mechanical model. Weyl ordering the corresponding Hamiltonian in phase space, an extra two-loop counterterm ${1/8}\bigg(R + g^{ij} Γ^{l}_{k i} Γ

H. Salehi, Y. Bisabr

We have used a two-dimensional analog of the Hadamard state-condition to study the local constraints on the two-point function of a linear quantum field conformally coupled to a two-dimensional gravitational background. We develop a dynamical model in which the determination of the state of the quantum field is essentially related to the determination of a c

I. S. Tsukerman

The quantity $ξ$ introduced recently in the phenomenological description of neutrino oscillations is in fact not a free parameter, but a fixed number.