November 1999 arXiv papers — page 3

Martin Janssen, Krystian Pracz

We study the statistics of eigenvectors in correlated random band matrix models. These models are characterized by two parameters, the band width B(N) of a Hermitian N times N matrix and the correlation parameter C(N) describing correlations of matrix elements along diagonal lines. The correlated band matrices show a much richer phenomenology than models wit

O. Deloubriere, H. J. Hilhorst

Motivated by certain problems of statistical physics we consider a stationary stochastic process in which deterministic evolution is interrupted at random times by upward jumps of a fixed size. If the evolution consists of linear decay, the sample functions are of the "random sawtooth" type and the level dependent persistence exponent θcan be calcula

A. Milchev, J. P. Wittmer, D. P. Landau

Polydisperse brushes obtained by reversible radical chain polymerization reaction onto a solid substrate with surface-attached initiators, are studied by means of an off-lattice Monte Carlo algorithm of living polymers (LP). Various properties of such brushes, like the average chain length and the conformational orientation of the polymers, or the force exer

Arindam Ghosh, A. K. Raychaudhuri

We report a novel phenomenon that the universal conductance fluctuations (UCF) can be suppressed by a small electric field E. The experiment has been carried out on single crystals of Si doped heavily with P and B beyond the critical composition of insulator to metal transition. The phenomenon is identified as a consequence of electric field induced dephasin

C. Ungarelli, S. Francaviglia, M. Macucci, G. Iannaccone

We investigate the effect of a finite temperature on the behavior of logic circuits based on the principle of Quantum Cellular Automata (QCA) and of ground state computation. In particular, we focus on the error probability for a wire of QCA cells that propagates a logic state. A numerical model and an analytical, more approximate, model are presented for th

V. Martín-Mayor, G. Parisi, P. Verrocchio

We study the spectral width as a function of the external momentum for the dynamical structure factor of a disordered harmonic solid, considered as a toy model for supercooled liquids and glasses. Both in the context of single-link coherent potential approximation and of a single-defect approximation, two different regimes are clearly identified: if the dens

J. Lages, D. L. Shepelyansky

We study numerically the ground state properties of the Cooper problem in the three-dimensional Anderson model. It is shown that attractive interaction creates localized pairs in the metallic noninteracting phase. This localization is destroyed at sufficiently weak disorder. The phase diagram for the delocalization transition in the presence of disorder and

X. Leyronas, P. G. Silvestrov, C. W. J. Beenakker

The chaotic mixing by random two-body interactions of many-electron Fock states in a confined geometry is investigated numerically and compared with analytical predictions. Two distinct regimes are found in the dependence of the inverse participation ratio in Fock space I on the dimensionless conductance of the quantum dot g and the excitation energy E. In b

K. Oda, T. Miyakawa, H. Yabu, T. Suzuki

The s-wave scattering length for the Positronium-Positronium interaction is estimated semi-phenomenologically with the long-range van der Waals force and the short-range repulsive potential that represents the hard core between two positronium. The obtained value of the scattering length is $a \sim 0.44{\rm nm}$, and its stability is also checked for differe

Denis J. Evans, E. G. D. Cohen, Debra J. Searles, F. Bonetto

A number of relations between the Kaplan-Yorke dimension, phase space contraction, transport coefficients and the maximal Lyapunov exponents are given for dissipative thermostatted systems, subject to a small external field in a nonequilibrium stationary state. A condition for the extensivity of phase space dimension reduction is given. A new expression for

E. Trias, J. J. Mazo, F. Falo, T. P. Orlando

We have measured the depinning of trapped kinks in a ratchet potential using a fabricated circular array of Josephson junctions. Our ratchet system consists of a parallel array of junctions with alternating cell inductances and junctions areas. We have compared this ratchet array with other circular arrays. We find experimentally and numerically that the dep

Adriana Moreo, Matthias Mayr, Adrian Feiguin, Seiji Yunoki

Computational studies show the generation of large coexisting metallic and insulating clusters with equal electronic density in models for manganites. The clusters are induced by disorder on exchange and hopping amplitudes near first-order transitions of the non-disordered strongly coupled system. The random-field Ising model is used to explain the qualitati

V. Senz, U. Doetsch, U. Gennser, T. Ihn

The low-temperature resistivity of a SiGe 2-dimensional hole gas has been studied using the gate controlled carrier density as a parameter. A metal-insulator transition is seen both in the temperature and in the electric field behaviour. Values of 1 for the dynamical exponent and 2.85 for the correlation length exponent are obtained from scaling plots. No qu

M. Giersz, R. Spurzem

The new approach outlined in Paper I (Spurzem \& Giersz 1996) to follow the individual formation and evolution of binaries in an evolving, equal point-mass star cluster is extended for the self-consistent treatment of relaxation and close three- and four-body encounters for many binaries (typically a few percent of the initial number of stars in the cluster)

Rita M. Sambruna, Michael Eracleous

The X-ray emission of radio-loud (RL) AGNs is a powerful tool for probing the structure of the accretion flow in these objects. We review recent spectral and variability studies of RL AGNs, which show that these systems have systematically different X-ray properties than their radio-quiet (RQ) counterparts. Specifically, RL AGNs have weaker and narrower Fe K

Dipak Munshi, Bhuvnesh Jain

Weak gravitational lensing surveys have the potential to directly probe mass density fluctuation in the universe. Recent studies have shown that it is possible to model the statistics of the convergence field at small angular scales by modeling the statistics of the underlying density field in the highly nonlinear regime. We propose a new method to model the

Avishai Dekel

I address the following issues: All bulk velocity measurements (but one) are consistent with our standard gravitational instability theory. New accurate data and reconstruction methods allow high-resolution dynamical analysis nearby, revealing Virgo, Ursa Major and Fornax as attractors. Large peculiar-velocity surveys enable robust reconstruction of the dyna

Anne J. Metevier, A. Kathy Romer, M. P. Ulmer

We present the results of Butcher-Oemler-style analysis of three moderate- redshift (0.1<z<0.2) clusters which have bimodal X-ray surface brightness profiles. We find that at least two of these clusters exhibit unusually high fractions of blue galaxies as compared to clusters at comparable redshifts studied by Butcher and Oemler (1984). This implies that sta

J-L. Atteia

We conjecture that bright gamma-ray bursts (GRBs) are bright because they come from sources which are intrinsically over luminous and not because they come from nearby sources. We show that this hypothesis is supported by theoretical and observational arguments and that it explains some well-known properties of GRBs such as their Hardness-Intensity Correlati

Mairi Sakellariadou

I present a briefly summary of the current status of inflationary models versus topological defects scenarios, as the mechanisms which could have induced the initial density perturbations, which left an imprint on the cosmic microwave backgound radiation anisotropies.

Isabella Gioia

We have used data from the deepest region of the ROSAT All-Sky Survey, the North Ecliptic Pole (NEP) region, to produce a complete and unbiased X-ray selected sample of distant clusters to understand the nature of cluster evolution and determine implications for large scale structure models. In this contribution results are presented from a comparison betwee

Francesco Paresce, Guido De Marchi

(Abridged) Accurate luminosity functions (LF) for a dozen globular clusters have now been measured at or just beyond their half-light radius using HST. They span almost the entire cluster main sequence below ~ 0.75 Msolar. All these clusters exhibit LF that rise continuously from an absolute I magnitude M_I ~ 6 to a peak at M_I ~ 8.5-9 and then drop with inc

A. N. Parmar, T. Peacock, M. Bavdaz, G. Hasinger

XEUS is under study by ESA as part of the Horizon 2000+ program to utilize the International Space Station (ISS) for astronomical applications. XEUS will be a long-term X-ray observatory with an initial mirror area of 6m2 at 1 keV that will be grown to 30m2 following a visit to the ISS. The 1 keV spatial resolution is expected to be 2-5&#39;&#39; HEW. XEUS w

Charles H. Lineweaver

The age of the universe in the Big Bang model can be calculated from three parameters: Hubble&#39;s constant, h; the mass density of the universe, Omega_m; and the cosmological constant, Omega_lambda. Recent observations of the cosmic microwave background and six other cosmological measurements reduce the uncertainty in these three parameters, yielding an ag

Shih-Ping Lai, Richard M. Crutcher

We have conducted a survey of the CCS $J_N = 3_2-2_1$ line toward 11 dark clouds and star-forming regions at 30 arcsec spatial resolution and 0.054 km/s velocity resolution. CCS was only detected in quiescent clouds, not in active star-forming regions. The CCS distribution shows remarkable clumpy structure, and 25 clumps are identified in 7 clouds. Seven clu

Hiroaki Nishioka, Kazuhiro Yamamoto

We examine the effects of the linear and the cosmological redshift-space distortions on the power spectrum of cosmological objects on a light cone. We develop theoretical formulae for the power spectrum in linear theory of density perturbations in a rigorous manner starting from first principle corresponding to Fourier analysis. Approximate formulae, which a

M. Pierre, G. Bryan, R. Gastaud

A large fraction of the baryons today are predicted to be in hot, filamentary gas, which has yet to be detected. In this paper, we use numerical simulations of dark matter and gas to determine if these filaments and groups of galaxy will be observable be XMM. The simulated maps include free-free and line emission, galactic absorption, the XMM response functi

Bohdan Paczynski

The ongoing microlensing searches have generated more photometric measurements of pulsating stars than all previous observing projects combined. In particular, OGLE has made ~ 340,000 B, V, and I-band measurements of ~ 1,300 Cepheids in the Large Magellanic Clouds accessible over Internet. Microlensing searches contributed to the development of very efficien

F. Aharonian, The HEGRA Collaboration

The HEGRA system of four Imaging Atmospheric Cherenkov Telescopes (IACTs) has been used to extensively observe extragalactic objects. In this paper we describe the search for TeV emission from nine very promising potential TeV sources, namely eight ``high frequency&#39;&#39; BL Lac objects (HBLs), and the object ``BL Lacertae&#39;&#39; itself. These objects

Z. Perjés

The various schemes for studying rigidly rotating perfect fluids in general relativity are reviewed. General conclusions one may draw from these are: (i) There is a need to restrict the scope of the possible ansatze, and (ii) the angular behaviour is a valuable commodity. This latter observation follows from a large number of analytic models exhibiting a NUT

A. Pelissetto, E. Vicari

We study the effective potential of three-dimensional O($N$) models. In statistical physics the effective potential represents the free-energy density as a function of the order parameter (Helmholtz free energy), and, therefore, it is related to the equation of state. In particular, we consider its small-field expansion in the symmetric (high-temperature) ph

John Bahcall, Raymond Davis,

How did neutrino astronomy evolve? Are there any useful lessons for astronomers and physicists embarking on new observational ventures today? We answer the first question; the reader can can decide if there are any useful parallels for other fields.

C. Presura, D. van der Marel, A. Damascelli, R. K. Kremer

The dielectric function of alpha&#39;NaV2O5 was measured with electric field along the a and b axes in the photon energy range 0.8-4.5 eV for temperatures down to 4K. We observe a pronounced decrease of the intensity of the 1 eV peak upon increasing temperature with an activation energy of about 25meV, indicating that a finite fraction of the rungs becomes o

Antonella Natta, Michael R. Meyer, Steven V. W. Beckwith

We present low-resolution mid-infrared spectra of nine classical T Tauri stars associated with the Chamaeleon I dark cloud. The data were obtained with the PHOT-S instrument on-board the Infrared Space Observatory (ISO) in the two wavelength ranges 2.5-4.9 and 5.9-11.7 microns. All nine stars show evidence of silicate emission at 10 microns, which is the onl

G. G. Adamian, N. V. Antonenko, W. Scheid

The dependence of fusion cross section on the isotopic composition of colliding nuclei is analysed within the dinuclear system concept for compound nucleus formation. Probabilities of fusion and surviving probabilities, ingredients of the evaporation residue cross sections, depend decisively on the neutron numbers of the dinuclear system. Evaporation residue

A. G. Ramm, M. Sammartino

Existence and uniqueness of the scattering solutions is proved for a class of bounded rough obstacles which is much larger than the class of Lipschitz obstacles. Integral equations method is not used. The approach is based on the representation theorem for selfadjoint operators via closed symmetric quadratic forms and on the limiting absorption principles. F

A. G. Ramm, W. Scheid

An approximate method is proposed for the recovery of a compactly supported spherically-symmetric potential from the set of fixed-energy phase-shifts known for all angular momenta. The method reduces the inverse scattering problem to a moment problem which is solved numerically. The above reduction is done approximately and it is more accurate for larger ang

Sakaé Fuchino, Stefan Geschke, Saharon Shelah, Lajos Soukup

The following results are proved: (a) In a model obtained by adding aleph_2 Cohen reals, there is always a c.c.c. complete Boolean algebra without the weak Freese-Nation property. (b) Modulo the consistency strength of a supercompact cardinal, the existence of a c.c.c. complete Boolean algebras without the weak Freese-Nation property consistent with GCH. (c)

Tapani Hyttinen, Saharon Shelah

We study elementary submodels of a stable homogeneous structure. We improve the independence relation defined in [T. Hyttinen, On nonstructure of elementary submodels of a stable homogeneous structure, Fundamenta Mathematicae, 156(1998): 167-182]. We apply this to prove a structure theorem. We also show that dop and sdop are essentially equivalent, where the

Mirna Džamonja, Saharon Shelah

We give two results on guessing unbounded subsets of lambda^+. The first is a positive result and applies to the situation of lambda regular and at least equal to aleph_3, while the second is a negative consistency result which applies to the situation of lambda a singular strong limit with 2^lambda>lambda^+. The first result shows that in ZFC there is a gue

Vadim E. Levit, Eugen Mandrescu

The stability number of a graph G is the cardinality of a stability system of G (that is of a stable set of maximum size of G). A graph is alpha-stable if its stability number remains the same upon both the deletion and the addition of any edge. Trying to generalize some stable trees properties, we show that there does not exist any alpha-stable chordal grap

Michael Farber, Serge Tabachnikov

We give lowed bounds on the number of periodic trajectories in strictly convex smooth billiards in $\R^{m+1}$ for $m\ge 3$. For plane billiards (when m=1) such bounds were obtained by G. Birkhoff in the 1920&#39;s. Our proof is based on topological methods of calculus of variations - equivariant Morse and Lusternik - Schirelman theories. We compute the equiv

Rami Grossberg, Saharon Shelah

Let lambda be aleph_0 or a strong limit of cofinality aleph_0. Suppose that (G_m,p_{m,n}:m =< n<omega) and (H_m,p^t_{m,n}: m=< n < omega) are projective systems of groups of cardinality less than lambda and suppose that for every n<omega there is a homomorphism h:H_n-->G_n such that all the diagrams commute. If for every mu<lambda there exists (f_i in G_omeg

Blake Mellor

This paper is a generalization of the author&#39;s previous work on link homotopy to link concordance. We show that the only real-valued finite type link concordance invariants are the linking numbers of the components.

Claudio A. Scrucca, Marco Serone

We review the anomaly inflow mechanism on D-branes and O-planes. In particular, we compute the one-loop world-volume anomalies and derive the RR anomalous couplings required for their cancellation.

Eric D&#39;Hoker, Samir D. Mathur, Alec Matusis, Leonardo Rastelli

We give a detailed Operator Product Expansion interpretation of the results for conformal 4-point functions computed from supergravity through the AdS/CFT duality. We show that for an arbitrary scalar exchange in AdS(d+1) all the power-singular terms in the direct channel limit (and only these terms) exactly match the corresponding contributions to the OPE o

Abel Camacho Quintana

The relation between Einstein equivalence principle and a continuous quantum measurement is analyzed in the context of the recently proposed flavor-oscillation clocks, an idea pioneered by Ahluwalia and Burgard (Gen. Rel Grav. Errata 29, 681 (1997)). We will calculate the measurement outputs if a flavor-oscillation clock, which is immersed in a gravitational

Joseph O&#39;Rourke, The Smith Problem Solving Group

We prove that a particular pushing-blocks puzzle is intractable in 3D. The puzzle, inspired by the game PushPush, consists of unit square blocks on an integer lattice. An agent may push blocks (but never pull them) in attempting to move between given start and goal positions. In the PushPush version, the agent can only push one block at a time, and moreover,

J. Ito, K. Kaneko

Formation of a layered structure is studied in a globally coupled map of chaotic units with a plastic coupling strength that changes depending on the states of units globally and an external input. In the parameter region characterized by weakly chaotic and desynchronized dynamics, units spontaneously form a hierarchical structure due to the influence of the

Arnon Dar

We show that young pulsars with normal magnetic fields, which are born as fast rotating neutron stars (NSs) in Type II/Ib supernova explosions, can slow down quickly by relativistic particles emission along their magnetic axis. When they slow down sufficiently, they can undergo phase transitions and collapse to strange stars, quark stars or black holes in ex

Luca Salasnich

We discuss the Bose-Einstein condensation (BEC) for an ideal gas of bosons in the framework of Tsallis&#39;s nonextensive statistical mechanics. We study the corrections to the standard BEC formulas due to a weak nonextensivity of the system. In particular, we consider three cases in the D-dimensional space: the homogeneous gas, the gas in a harmonic trap an

John A. Gowan

A geometric spacetime map of the universe is presented, addressing problems inherent in deep space observations and cosmology. Implications for the observer&#39;s perspective, the cosmological &#34;horizon&#34; and &#34;flatness&#34; problem, &#34;inflation&#34;, and the recently observed accelerating expansion of the Universe are discussed.

I. L. Buchbinder, S. M. Kuzenko, A. A. Tseytlin

We study some aspects of low-energy effective actions in 4-d superconformal gauge theories on the Coulomb branch. We describe superconformal invariants constructed in terms of N=2 abelian vector multiplet which play the role of building blocks for the N=2,4 supersymmetric low-energy effective actions. We compute the one-loop effective actions in constant N=2

Z. V. Merebashvili, A. P. Contogouris, G. Grispos

Results of our next-to-leading order analytic calculation for longitudinally polarized photoproduction of heavy quarks are presented. Certain differential cross sections and the corresponding asymmetries are computed for energy ranges accessible to CERN and HERA. We argue that determination of the polarized gluon distribution is possible at both places: at H

C. Schindelin, H. Fehske, H. Büttner, D. Ihle

We present a Green&#39;s-function theory of magnetic short-range order in the $S=1/2$ easy-plane XXZ chain based on the projection method for the dynamic spin susceptibility and a decoupling of three-spin operator products introducing vertex parameters. The longitudinal and transverse static susceptibilities and two-point correlation functions of arbitrary r

Bohdan Grzadkowski, Zenro Hioki

Angular and energy distributions for leptons and bottom quarks in the process e^+e^- --> t t-bar --> l^{+-}/b(b-bar) ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on modification of the t t-bar production and t(t-bar) --> b(b-bar) W decay vertices. However, the leptonic angular distribution turne

J. S. Milne

Tate's theorem (Invent. Math. 1966)implies that the Tate conjecture holds for any abelian variety over a finite field whose Q_l-algebra of Tate classes is generated by those of degree 1. We construct families of abelian varieties over finite fields for which this condition fails, but for which we are nevertheless able to prove the Tate conjecture.

Ar. Abanov, Andrey V. Chubukov, A. M. Finkel&#39;stein

We study the superconductivity in 2D fermionic systems near antiferromagnetic instability, assuming that the pairing is mediated by spin fluctuations. This pairing involves fully incoherent fermions and diffusive spin excitations. We show that the competition between fermionic incoherence and strong pairing interaction yields the pairing instability temperat

A. G. Ramm

An inverse problem is considered for an inhomogeneous Schrödinger equation. Assuming that the potential vanishes outside a finite interval and satisfies some other technical assumptions, one proves the uniqueness of the recovery of this potential from the knowledge of the wave function at the ends of the above interval for all energies. An algorithm is given

A. G. Ramm

Foundations of the theory of Hilbert spaces with reproducing kernels are discussed. It is demonstrated that the claims in the papers of S.Saitoh and in his book &#34;Theory of reproducing kernels and applications, Pitman research notes, 189, Longman, New York, 1988, that a characterization of the range of arbitrary linear transform is obtained in his works,

A. G. Ramm

The limiting absorption principle in two-dimensional space is justified for a second-order elliptic operators. Necessary and sufficient conditions for the right-hand side are given for this principle to be valid.

R. Airapetyan, A. G. Ramm, A. Smirnova

A general method for solving nonlinear ill-posed problems is developed. The method consists of solving a Cauchy problem with a regularized operator and proving that the solution of this problem tends, as time grows, to a solution of the original nonlinear stationary problem. Examples of applications of the general method are given. Convergence theorems are p

A. G. Ramm, P. N. Shivakumar

It is proved that the minimal Dirichlet eigenvalue of the Laplacian in an annulus is a monotonically decreasing function of the displacement of the center of the smaller disc. The maximal value of the minimal eigenvalue is attained when the annulus is formed by two concentric discs.

Xiaoping Xu

In this paper, we introduce two new families of infinite-dimensional simple Lie algebras and a new family of infinite-dimensional simple Lie superalgebras. These algebras can be viewed as generalizations of the Block algebras.

Xiaoping Xu

We construct four new series of generalized simple Lie algebras of Cartan type, using the mixtures of grading operators and down-grading operators. Our results in this paper are further generalizations of those in Osborn&#39;s work ``New simple infinite-dimensional Lie algebras of characteristic 0.&#39;&#39;

Xiaoping Xu

In this paper, we shall classify ``quadratic&#39;&#39; conformal superalgebras by certain compatible pairs of a Lie superalgebra and a Novikov superalgebra.Four general constructions of such pairs are given. Moreover, we shall classify such pairs related to simple Novikov algebras.

Tohru Eguchi, Masao Jinzenji

We discuss a possible generalization of the Calabi-Yau/Landau-Ginzburg correspondence to a more general class of manifolds. Specifically we consider the Fermat type hypersurfaces $M_N^k$: $\sum_{i=1}^N X_i^k =0$ in ${\bf CP}^{N-1}$ for various values of k and N. When k<N, the 1-loop beta function of the sigma model on $M_N^k$ is negative and we expect the th

Paolo Ciafaloni

The planned next generation of linear colliders (NLCs) will be able to probe the infrared structure of Standard Model electroweak interactions, that determines the behavior of electroweak radiative corrections at TeV scale energies. I present results of a recent calculation at the leading log level, and discuss my view on open issues and possible future deve

A. A. Pivovarov

A solution to the Schrodinger equation for the nonrelativistic Green function which is used for describing the heavy quark-antiquark pair production near the threshold in $e^+e^-$ annihilation is presented. A quick comparison with existing results is given. A choice of the effective mass scale for the nonrelativistic system with Coulomb interaction is discus

S. Dalley, B. van de Sande

Accurate non-perturbative calculations of glueballs are performed using light-front quantised SU(N) gauge theory, to leading order of the 1/N expansion. Based on early work of Bardeen and Pearson, disordered gauge-covariant link variables M on a coarse transverse lattice are used to approximate the physical gauge degrees of freedom. Simple energetics imply t

TARO Collaboration, Ph. de Forcrand, M. Garcia Perez, T. Hashimoto

We study the response of hadron masses with respect to chemical potential at $μ=0$. Our preliminary results of the pion channel show that $\partial m/\partial μ$ in the confinement phase is significantly larger than that in the deconfinement phase, which is consistent with the chiral restoration.

Osvaldo M. Moreschi

We show that there are implications on thermodynamics that come from the existence of the initial cosmic singularity. At present time this is more a conceptual change than an observable one. However at very early cosmic times there is a big difference between the actual behavior of thermodynamic quantities and the behavior assumed in the standard cosmologica

W. B. Belayev

The tired-light cosmology is considered in the framework of Kaluza-Klein theory in 5D. The solution of the five-dimensional semi-classical Einstein equations with nonzero five-dimensional energy-momentum tensor gives density of matter in the Universe well conformed to the observations. Variation of the light velocity and change of the rest energy and mass ar

V. I. Kozub, N. V. Agrinskaya, S. I. Khondaker, I. Shlimak

A simple two-band model is suggested explaining recently reported unusual features for hopping magnetoresistance and the metal-insulator transition in 2D structures. The model implies that the conductivity is dominated by the upper Hubbard band (D^- band). Experimental studies of hopping magnetoresistance for Si delta doped GaAs/AlGaAs heterostructure give a

Matteo Palassini, Sergio Caracciolo

We study the 3D Edwards-Anderson model with binary interactions by Monte Carlo simulations. Direct evidence of finite-size scaling is provided, and the universal finite-size scaling functions are determined. Using an iterative extrapolation procedure, Monte Carlo data are extrapolated to infinite volume up to correlation length ξ= 140. The infinite volume da

T. Yoshida, A. Ino, T. Mizokawa, A. Fujimori

We have performed a photoemission study of La$_{1-x}$Sr$_x$TiO$_{3+y/2}$ near the filling-control metal-insulator transition (MIT) as a function of hole doping. Mass renormalization deduced from the spectral weight and the width of the quasi-particle band around the chemical potential $μ$ is compared with that deduced from the electronic specific heat. The r

A. Odintsov, H. Yoshioka

Single-wall carbon nanotubes are almost ideal systems for the investigation of exotic many-body effects due to non-Fermi liquid behavior of interacting electrons in one dimension. Recent theoretical and experimental results are reviewed with a focus on electron correlations. Starting from a microscopic lattice model we derive an effective phase Hamiltonian f

Ihor A. Lubashevsky, Reinhard Mahnke

We discuss a phenomenological approach to the description of unstable vehicle motion on multilane highways that could explain in a simple way such observed self-organizing phenomena as the sequence of the phase transitions &#34;free flow -> synchronized motion -> jam&#34; and the hysteresis in them. We introduce a new variable called order parameter that acc

Shunguang Wu, Da-Ren He

Many systems can display a very short, rapid changing stage (quasi-discontinuous region) inside a relatively very long and slowly changing process. A quantitative definition for the &#34;quasi-discontinuity&#34; in these systems has been introduced. We have shown by a simplified model that extra-large Feigenbaum constants can be found inside some period-doub

Zakir F. Seidov

Two-imcompressible phase model of star is briefly revised. Effects of rotation and general relativity are considered.

E. Schinnerer, A. Eckart, L. J. Tacconi, R. Genzel

We present new interferometer observations of the 12CO(1-0) and 12CO(2-1) line emission of NGC 1068 with a resolution of 0.7&#39;&#39;. The molecular gas in the inner 5&#39;&#39; is resolved into a ring with two bright knots east and west of the nuclear continuum emission. For the first time in NGC 1068, we can trace molecular gas at ~0.18&#39;&#39; (13pc) f

E. Schinnerer, A. Eckart, L. J. Tacconi

We present new interferometric observations of the 12CO(1-0), 12CO(2-1) and HCN (1-0) molecular line emission in NGC 3227 obtained with the IRAM Plateau de Bure interferometer (PdBI). We achieved an unprecedented angular resolution in the 12CO(2-1) line of about 0.6&#39;&#39; corresponding to only about 80pc at a distance of 17.3Mpc. The mapped 12CO emission

M. Girardi, W. Boschin, L. da Costa, ;

We measure the two-point redshift-space correlation function of loose groups of galaxies, xi_GG, for the combined CfA2 and SSRS2 surveys. Our combined group catalog constitutes the largest homogeneous sample available (885 groups). We compare xi_GG with the correlation function of galaxies, xi_gg, in the same volume. We find that groups are significantly mor

Nataliya A. Zimbovskaya, Joseph L. Birman

We consider the effect of local flattening on the Fermi surface (FS) of a metal upon geometric oscillations of the velocity and attenuation of ultrasonic waves in the neighborhood of the acoustic cyclotron resonance. It is shown that such peculiarities of the local geometry of the FS can lead to a significant enhancement of both cyclotron resonance and geome

D. V. Dmitriev, V. Ya. Krivnov, A. A. Ovchinnikov

We have proposed several 1D and 2D electronic models with the exact ground state. The ground state wave function of these models is represented in terms of &#34;singlet bond&#34; functions consisting of homopolar and ionic configurations. The Hamiltonians of the models include the correlated hopping of electrons, pair hopping terms and the spin interactions.

C. O. Lousto

We consider the problem of evolving nonlinear initial data in the close limit regime. Metric and curvature perturbations of nonrotating black holes are equivalent to first perturbative order, but Moncrief waveform in the former case and Weyl scalar $ψ_4$ in the later differ when nonlinearities are present. For exact Misner initial data (two equal mass black

C. Boehm, A. Djouadi, M. Drees

A stable neutralino $χ_1^0$, assumed to be the lightest supersymmetric particle, is a favored particle physics candidate for the cosmological Dark Matter. We study co-annihilation of the lightest neutralino with the lighter scalar top quark $\tilde{t}_1$. We show that for natural values of the neutralino mass, $\lsim 300$ GeV, the $χ_1^0 - \tilde{t}_1$ mass

C. W. M. Castleton, M. Altarelli

It is proposed that the observation of orbital ordering in manganite materials should be possible at the L_II and L_III edges of manganese using X-ray resonant scattering. If performed, dipole selection rules would make the measurements much more direct than the disputed observations at the manganese K edge. They would yield specific information about the ty

Donam Youm

We study some aspects of dilatonic domain walls in relation to the idea on the noncompact internal space. We find that the warp factor in the spacetime metric increases as one moves away from the domain wall for all the supersymmetric dilatonic domain wall solutions obtained from the (intersecting) BPS branes in string theories through toroidal compactificat

M. S. Joshi, W. R. B. Lionheart

We show that the full symbol of the Dirichlet to Neumann map of the k-form Laplace's equation on a Riemannian manifold (of dimension greater than 2) with boundary determines the full Taylor series, at the boundary, of the metric. This extends the result of Lee and Uhlmann for the case $k=0$. The proof avoids the computation of the full symbol by using the ca

M. Caselle, M. Hasenbusch

We compute the spectrum and several critical amplitudes of the two dimensional Ising model in a magnetic field with the transfer matrix method. The three lightest masses and their overlaps with the spin and the energy operators are computed on lattices of a width up to L=21. In extracting the continuum results we also take into account the corrections to sca

Anthony Challinor

We introduce a new multipole formalism for polarized radiative transfer in general spacetime geometries. The polarization tensor is expanded in terms of coordinate-independent, projected symmetric trace-free (PSTF) tensor-valued multipoles. The PSTF representation allows us to discuss easily the observer dependence of the multipoles of the polarization, and

I. V. Bargatin, B. A. Grishanin, V. N. Zadkov

We explore the possibilities of creating radiatively stable entangled states of two three-level dipole-interacting atoms in a $Λ$ configuration by means of laser biharmonic continuous driving or pulses. We propose three schemes for generation of entangled states which involve only the lower states of the $Λ$ system, not vulnerable to radiative decay. Two of

Ph. de Forcrand, M. García Pérez, T. Hashimoto, S. Hioki

We investigate the renormalization group (RG) flow of SU(3) lattice gauge theory in a two coupling space with couplings $β_{11}$ and $β_{12}$ corresponding to $1\times 1$ and $1\times 2$ loops respectively. Extensive numerical calculations of the RG flow are made in the fourth quadrant of this coupling space, i.e., $β_{11}>0$ and $β_{12}<0$. Swendsen&#39;s f

D. Kremp, D. Semkat, M. Bonitz

The Kadanoff-Baym equations (KBE) are usually derived under the assumption of the weakening of initial correlations (Bogolyubov's condition) and, therefore, fail to correctly describe the short time behavior. We demonstrate that this assumption is not necessary. Using functional derivatives techniques, we present a straightforward generalization of the KBE w

The WA102 Collaboration, D. Barberis

The reaction pp -> pf (eta pi pi) ps has been studied at 450 GeV/c. There is clear evidence for an a2(1320)pi decay mode of the eta2(1645) and eta2(1870). In addition, there is evidence for an a0(980)pi$ decay mode of both resonances and an f2(1270)eta decay mode of the eta2(1870). No evidence is found for a JPC = 2++ a2(1320)pi wave.

Enrique Alvarez, César Gómez

The renormalization group approach towards the string representation of non abelian gauge theories translates, in terms of the string sigma model beta function equations, the renormalization group evolution of the gauge coupling constant and Zamolodchikov`s $c$ function. Tachyon stability, glueball mass gap, renormalization group evolution of the $c$ functio

Helmut Friedrich, Janos Kannar

We discuss how asymptotic quantities, originally introduced on null infinity in terms of Bondi-type gauge conditions, can be calculated near space-like infinity to any desired precision.

T. Quella

Based on the rational R-matrix of the supersymmetric sl(2,1) matrix difference equations are solved by means of a generalization of the nested algebraic Bethe ansatz. These solutions are shown to be of highest-weight with respect to the underlying graded Lie algebra structure.

Volodymyr Lyubashenko

Under some assumptions we prove that the Deligne tensor product of categories of constructible perverse sheaves on pseudomanifolds X and Y is the category of constructible perverse sheaves on X\times Y. The Deligne external tensor product functor is identified with the geometrical external tensor product.