September 2003 arXiv papers — page 15

Yamaguchi Y. Yoshiyuki

The relation between relaxation and diffusion is investigated in a Hamiltonian system of globally coupled rotators. Diffusion is anomalous if and only if the system is going towards equilibrium. The anomaly in diffusion is not anomalous diffusion taking a power-type function, but is a transient anomaly due to non-stationarity. Contrary to previous claims, in

Miloslav Znojil, Denis Yanovich

Schroedinger bound-state problem in D dimensions is considered for a set of central polynomial potentials (containing 2q coupling constants). Its polynomial (harmonic-oscillator-like, quasi-exact, terminating) bound-state solutions of degree N are sought at a (q+1)-plet of exceptional couplings/energies, the values of which comply with (the same number of) t

Pengzi Miao

We extend the idea and techniques in \cite{Miao} to study variational effect of the boundary geometry on the ADM mass of an asymptotically flat manifold. We show that, for a Lipschitz asymptotically flat metric extension of a bounded Riemannian domain with quasi-convex boundary, if the boundary mean curvature of the extension is dominated by but not identica

F. Hiroshima, K. R. Ito

A one-parameter symplectic group $\{e^{t\dA}\}_{t\in\RR}$ derives proper canonical transformations on a Boson Fock space. It has been known that the unitary operator $U_t$ implementing such a proper canonical transformation gives a projective unitary representation of $\{e^{t\dA}\}_{t\in\RR}$ and that $U_t$ can be expressed as a normal-ordered form. We rigor

Oscar Bolina, Pierluigi Contucci, Bruno Nachtergaele

Two discrete path integral formulations for the ground state of a spin-pinned quantum anisotropic XXZ Heisenberg chain are introduced. Their properties are discussed and two recursion relations are proved.

S. Oblezin

In the present work we calculate the group structure of the Schlesinger transformations for isomonodromic deformations of order two Fuchsian differential equations. We perform these transformations as the isomorphisms between the moduli spaces of the logarithmic sl(2)- connections with fixed eigenvalues of residues at singular points. We give the geometrical

Aureli Alabert, Miguel A. Marmolejo

We consider one-dimensional stochastic differential equations with a boundary condition, driven by a Poisson process. We study existence and uniqueness of solutions and the absolute continuity of the law of the solution. In the case when the coefficients are linear, we give an explicit form of the solution and study the reciprocal process property.

John W. Jones, David P. Roberts

We describe our online database of finite extensions of the p-adic numbers, and how it can be used to facilitate local analysis of number fields.

Eric Sommers

For the classical groups, Kraft and Procesi have resolved the question of which nilpotent orbits have closures which are normal and which are not, with the exception of the very even orbits in $D_{2l}$ which have partition of the form $(a^{2k}, b^2)$ for $a, b$ distinct even natural numbers with $a k + b = 2 l$. In this article, we show that these orbits do

Franck Melliez, Kristian Ranestad

The moduli space of (1,7)-polarized abelian surfaces with a level structure was shown by Manolache and Schreyer to be rational with compactification a Fano 3-fold of genus 12 which is also a compactification of the variety of powersum presentations of the Klein quartic curve. In this paper the possible degenerations of the abelian surfaces are classified in

Dave Broomhead, James Montaldi, Nikita Sidorov

We consider the iterated function systems (IFSs) that consist of three general similitudes in the plane with centres at three non-collinear points, and with a common contraction factor $\la\in(0,1)$. As is well known, for $\la=1/2$ the invariant set, $§_\la$, is a fractal called the Sierpiński sieve, and for $\la<1/2$ it is also a fractal. Our goal is to stu

Jiachen Ye, Zhongguo Zhou

A monomial basis and a filtration of subalgebras for the universal enveloping algebra $U(g_l)$ of a complex simple Lie algebra $g_l$ of type $A_l$ is given in this note. In particular, a new multiplicity formula for the Weyl module $V(\lambda)$ of $U(g_l)$ is obtained in this note.

Yuwang Hu, Jiachen Ye

All the 62 monomial elements in the canonical basis B of the quantized enveloping algebra for type $A_4$ have been determined in [2]. According to Lusztig's idea [7], the elements in the canonical basis B consist of monomials and linear combinations of monomials (for convenience, we call them polynomials). In this note, we compute all the 144 polynomial elem

Thierry Bodineau

For the FK representation of the Ising model, we prove that the slab percolation threshold coincides with the critical temperature in any dimension larger or equal to three.

Sakae Fuchino, Stefan Geschke

We give an equivalent, but simpler formulation of the axiom SEP introduced by Juhasz and Kunen. Our formulation shows that many of the consequences of the weak Freese-Nation Property of $\mathcal P(ω)$ already follow from SEP. We show that it is consistent that SEP holds while $\mathcal P(ω)$ fails to have the $(\aleph_1,\aleph_0)$-ideal property, which has

Luc Moreau, Eduardo Sontag

Some biological systems operate at the critical point between stability and instability and this requires a fine-tuning of parameters. We bring together two examples from the literature that illustrate this: neural integration in the nervous system and hair cell oscillations in the auditory system. In both examples the question arises as to how the required

Tsuyoshi Kajiwara, Yasuo Watatani

Iteration of a rational function $R$ gives a complex dynamical system on the Riemann sphere. We introduce a $C^*$-algebra ${\mathcal O}_R$ associated with $R$ as a Cuntz-Pimsner algebra of a Hilbert bimodule over the algebra $A = C(J_R)$ of continuous functions on the Julia set $J_R$ of $R$. The algebra ${\mathcal O}_R$ is a certain analog of the crossed pro

Chandrashekhar Khare

The main result of the paper is a reciprocity law which proves that compatible systems of semisimple, abelian mod $p$ representations (of arbitrary dimension) of absolute Galois groups of number fields, arise from Hecke characters. In the last section of the paper analogs for Galois groups of function fields of these results are explored, and a question is r

Takeshi Katsura

We study $C^*$-algebras arising from $C^*$-correspondences, which was introduced by the author. We prove the gauge-invariant uniqueness theorem, and obtain conditions for our $C^*$-algebras to be nuclear, exact, or satisfy the Universal Coefficient Theorem. We also obtain a 6-term exact sequence of $K$-groups involving the $K$-groups of our $C^*$-algebras.

Peter Magyar

We give a new model for the crystal graphs of an affine Lie algebra g^, combining Littelmann&#39;s path model with the Kyoto path model. The vertices of the crystal graph are represented by certain infinitely looping paths which we call skeins. We apply this model to the case when the corresponding finite-dimensional algebra g has a minuscule representation

Eric M. Opdam

An affine Hecke algebra H contains a large abelian subalgebra A. The center Z of H is the subalgebra of Weyl group invariant elements in A. The natural trace of the affine Hecke algebra can be written as an integral of a rational $n$ form (with values in the linear dual of H) over a certain cycle in the algebraic torus T=spec(A). We derive the Plancherel for

Boyu Hou, Ryu Sasaki, Wen-Li Yang

Ruijsenaars-Schneider models associated with $A_{n-1}$ root system with a discrete coupling constant are studied. The eigenvalues of the Hamiltonian are givein in terms of the Bethe ansatz formulas. Taking the &#34;non-relativistic&#34; limit, we obtain the spectrum of the corresponding Calogero-Moser systems in the third formulas of Felder et al [20].

David E. Carneiro, A. P. Baêta Scarpelli, Marcos Sampaio, M. C. Nemes

We compute the three loop $\beta$ function of the Wess-Zumino model to motivate implicit regularization (IR) as a consistent and practical momentum-space framework to study supersymmetric quantum field theories. In this framework which works essentially in the physical dimension of the theory we show that ultraviolet are clearly disantangled from infrared di

C. P. Burgess, R. Kallosh, F. Quevedo

We propose a new mechanism for obtaining de Sitter vacua in type IIB string theory compactified on (orientifolded) Calabi-Yau manifolds similar to those recently studied by Kachru, Kallosh, Linde and Trivedi (KKLT). dS vacuum appears in KKLT model after uplifting an AdS vacuum by adding an anti-D3-brane, which explicitly breaks supersymmetry. We accomplish t

Rafael Ferraro

The electrostatic configurations of the Born-Infeld field in the 2-dimensional Euclidean plane are obtained by means of a non-analytical complex mapping which captures the structure of equipotential and field lines. The electrostatic field reaches the Born-Infeld limit value when the field lines become tangent to an epicycloid around the origin. The total en

Lorenz Hartmann, John R. Klauder

Weak coherent states share many properties of the usual coherent states, but do not admit a resolution of unity expressed in terms of a local integral. They arise e.g. in the case that a group acts on an inadmissible fiducial vector. Motivated by the recent Affine Quantum Gravity Program, the present article studies the path integral representation of the af

W. Bietenholz, F. Hofheinz, J. Nishimura

The UV/IR mixing in the λϕ^4 model on a non-commutative (NC) space leads to new predictions in perturbation theory, including Hartree-Fock type approximations. Among them there is a changed phase diagram and an unusual behavior of the correlation functions. In particular this mixing leads to a deformation of the dispersion relation. We present numerical resu

V. I. Ritus

The symmetry between the creation of pairs of massless bosons or fermions by accelerated mirror in 1+1 space and the emission of single photons or scalar quanta by electric or scalar charge in 3+1 space is deepened in this paper. The relation of Bogoliubov coefficients with Fourier's components of current or charge density leads to the coicidence of the spin

Y. S. Myung

We study a close relationship between the topological anti-de Sitter (TAdS)-black holes and topological de Sitter (TdS) spaces including the Schwarzschild-de Sitter (SdS) black hole in five-dimensions. We show that all thermal properties of the TdS spaces can be found from those of the TAdS black holes by replacing $k$ by $-k$. Also we find that all thermal

Roni Harnik, Daniel T. Larson, Hitoshi Murayama

Recent interest in novel phases in high density QCD motivates the study of high density supersymmetric QCD (SQCD), where powerful exact results for supersymmetric gauge theories can be brought to bear in the strongly coupled regime. We begin by describing how a chemical potential can be incorporated into a supersymmetric theory as a spurion vector superfield

A. I. Onishchenko, V. N. Velizhanin

We are studying scale properties of twist-2 conformal operators in supersymmetric Wess-Zumino model. In particular, we are interested in a construction of multiplicatively renormalized conformal operators. We show, that in order to find multiplicatively renormalized operators in this model, it is sufficient to find multiplicatively renormalized operators onl

Nick E Mavromatos

I discuss various ways in which CPT symmetry may be violated, and their phenomenology in current or immediate future experimental facilities, both terrestrial and astrophysical. Specifically, I discuss first violations of CPT symmetry due to the impossibility of defining a scattering matrix as a consequence of the existence of microscopic or macroscopic spac

Zoltan Ligeti

The determinations of |Vcb| and |Vub| from semileptonic B decays are reviewed with a critical discussion of the theoretical uncertainties and concentrating on recent developments. Future prospects and limitations are also discussed.

J. -M. Frere, G. Moreau, E. Nezri

We study a multi-localization model for charged leptons and neutrinos, including the possibility of a see-saw mechanism. This framework offers the opportunity to allow for realistic solutions in a consistent model without fine-tuning of parameters, even if quarks are also considered. Those solutions predict that the large Majorana mass eigenvalues for right-

F. Muheim

We review the status of inclusive |Vub| measurements where many new results have become available recently.

Johan Bijnens, Elvira Gamiz, Joaquim Prades

We review some work done by us calculating matrix elements for Kaons. Emphasis is put on the matrix elements which are relevant to predict non-leptonic Kaon CP violating observables. In particular, we recall our results for the \hat B_K parameter which governs the \bar{K^0}-K^0 mixing and update our results for epsilon&#39;_K including estimated all-higher-o

Gustavo C. Branco

We describe the role of CP violation in the generation of the baryon asymmetry of the Universe, in the framework of baryogenesis through leptogenesis, with emphasis on the possible relationship between CP violation at low energies and that required by leptogenesis. It is emphasized that a direct link between these two manifestations of CP violation only exis

Enrico Meggiolaro

We discuss the role of the U(1) axial symmetry for the phase structure of QCD at finite temperature. In particular, supported by recent lattice results, we analyse a scenario in which a U(1)-breaking condensate survives across the chiral transition. This scenario can be consistently reproduced using an effective Lagrangian model. The effects of the U(1) chir

Jong-Phil Lee

We calculate the $B\Bbar$ mixing in the Randall-Sundrum bulk model. In this model, all the Standard Model fields except the Higgs can reside in the bulk. Two suggestive models of &#34;mixed&#34; and &#34;relaxed&#34; scenarios are considered. We find that the enhancement of the loop function is 0.51% for the &#34;relaxed&#34; and 1.07% for the &#34;mixed&#34

Damir Becirevic, Juan Reyes

We show that by combining the static heavy quark action with the Neuberger action for the light quark, the renormalisation of the heavy-light bilinear and four-quark operators, computed on the lattice, becomes highly simplified: all the heavy-light bilinears get renormalised by a single multiplicative constant, whereas the renormalisation of the complete set

P. Faccioli, T. A. DeGrand

We report on a recent investigation on the dynamics of light quarks, at intermediate and low energy. By measuring some appropriate correlation functions on the lattice, it is possible to probe the Dirac and flavor structure of the non-perturbative quark-quark interaction and look directly for signatures of the &#39;t Hooft Lagrangian. Results obtained with c

Ph. Boucaud, V. Gimenez, C. -J. D. Lin, V. Lubicz

We present a numerical computation of matrix elements of DI=3/2 K-->pi pi decays by using Wilson fermions. In order to extrapolate to the physical point we work at unphysical kinematics and we resort to Chiral Perturbation Theory at the next-to-leading order. In particular we explain the case of the electroweak penguins O_{7,8} which can contribute significa

Tereza Mendes

Monte Carlo simulations applied to the lattice formulation of quantum chromodynamics (QCD) enable a study of the theory from first principles, in a nonperturbative way. After over two decades of developments in the methodology for this study and with present-day computers in the teraflops range, lattice-QCD simulations are now able to provide quantitative pr

I. Wetzorke, M. Guagnelli, K. Jansen, F. Palombi

We report on recent results for the pion matrix element of the twist-2 operator corresponding to the average momentum of non-singlet quark densities. For the first time finite volume effects of this matrix element are investigated and come out to be surprisingly large. We use standard Wilson and non-perturbatively improved clover actions in order to control

S. O. Bilson-Thompson, W. Lee

We study various methods of constructing fat links based upon the HYP (by Hasenfratz & Knechtli) and Fat7-bar (by W. Lee) algorithms. We present the minimum plaquette distribution for these fat links. This enables us to determine which algorithm is most effective at reducing the spread of plaquette values.

Takumi Doi, Noriyoshi Ishii, Makoto Oka, Hideo Suganuma

We study the quark-gluon mixed condensate g<\bar{q} σG q> using the SU(3)c lattice QCD with the Kogut-Susskind fermion at the quenched level. We perform the first but accurate measurement of the thermal effects on the mixed condensate in lattice QCD at β= 6.0 with 16^3 * Nt (Nt=16,12,10,8,6,4), β= 6.1 with 20^3 * Nt (Nt=20,12,10,8,6), and β= 6.2 with 24^3 *

SLD Collaboration, Koya Abe

We have made the first measurement of the double-inclusive B/Bbar energy distribution in e+e- annihilations, using a sample of 400,000 hadronic Z0 decay events recorded in the SLD experiment at SLAC between 1996 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector were used to reconstruct B/Bbar decay vertices with high efficiency a

The DELPHI Collaboration, J. Abdallah

DELPHI results are presented on the inclusive production of two (K Kbar pi)^0 states in the mass region 1.2-1.6 GeV/c^2 in hadronic Z decays at LEP I. The measured masses (widths) are 1274 +/- 6 MeV/c^2 (29 +/- 12 MeV/c^2) and 1426 +/- 6 MeV/c^2 (51 +/- 14 MeV/c^2) respectively. A partial-wave analysis of the (K Kbar pi)^0 system shows that the first peak is

L3 Collaboration

A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at centre-of-mass energies between 189 and 209GeV, corresponding to an integrated luminosity of 629.4/pb. Decays into a charm and a strange quark or into a tau lepton and its neutrino are considered. No significant excess is observed and lower limits

M. N. Achasov, K. I. Beloborodov, A. V. Berdyugin, A. G. Bogdanchikov

The review of the SND results of the $e^+e^-\toπ^+π^-π^0$ process study in the energy range $\sqrt[]{s}=0.42$ -- 1.38 GeV at VEPP-2M collider, based on about $2\times 10^6$ selected events, is presented. The total cross section, parameters of the $ρ$, $ω$, $ϕ$ resonances, and $ω^\prime$, $ω^{\prime\prime}$ states were obtained. It was found that $ρπ$ and $ωπ

Julian Barbour

A new approach to the dynamics of the universe based on work by O Murchadha, Foster, Anderson and the author is presented. The only kinematics presupposed is the spatial geometry needed to define configuration spaces in purely relational terms. A new formulation of the relativity principle based on Poincare&#39;s analysis of the problem of absolute and relat

Stephane Fay

We study in which conditions the Hyperextended Scalar Tensor theory in an FLRW background admits a Noether symmetry and derive the vectors field generating it.

Stephane Fay

We look for sufficient conditions such that the scalar curvature, Ricci and Kretchmann scalars be bounded in Hyperextended Scalar Tensor theory for Bianchi models. We find classes of gravitation functions and Brans-Dicke coupling functions such that the theories thus defined avoid the singularity. We compare our results with these found by Rama in the framew

Stephane Fay

The dynamics of the hyperextended scalar-tensor theory in the empty Bianchi type I model is investigated. We describe a method giving the sign of the first and second derivatives of the metric functions whatever the coupling function. Hence, we can predict if a theory gives birth to expanding, contracting, bouncing or inflationary cosmology. The dynamics of

Stephane Fay

We study the generalized scalar tensor theory with a potential in the Bianchi type I model by using the ADM formalism. We examine the conditions for the Universe to be in expansion, isotropic and with a positive potential at late time in the Brans-Dicke and Einstein frames. In particular, we analyse the two important cases where metric functions tend, in an

P. Kuusk, M. Saal

A cosmological scenario with two branes (A and B) moving in a 5-dimensional bulk is considered. As in the case of ecpyrotic and born-again braneworld models it is possible that the branes collide. The energy-momentum tensor is taken to describe a perfect barotropic fluid on the A-brane and a phenomenological time-dependent &#34;cosmological constant&#34; on

Ren-Bao Liu, Bang-Fen Zhu

A theory for nonlinear optics of semiconductors in the presence of an intense terahertz electric field is constructed based on the double-line Feynman diagrams, in which the nonperturbative effect of the intense terahertz field is fully taken into account through using the Floquet states as propagating lines in the Feynman diagrams.

M. N. Huda, A. K. Ray

A class of highly symmetric silicon carbide fullerene-like cage nanoclusters with carbon atoms inside the Si_20 cage and with high stability are presented. The Generalized Gradient Approximation of Density Functional Theory (GGA-DFT) is used to study the electronic and geometric structure properties of these structures and full geometry optimizations are per

Valmir C. Barbosa, Raul Donangelo, Sergio R. Souza

We study directed random graphs (random graphs whose edges are directed) as they evolve in discrete time by the addition of nodes and edges. For two distinct evolution strategies, one that forces the graph to a condition of near acyclicity at all times and another that allows the appearance of nontrivial directed cycles, we provide analytic and simulation re

Emmanuel I. Rashba

Spin-orbit interaction couples electron spins to electric fields and allows electrical monitoring of electron spins and electrical detection of spin dynamics. Competing mechanisms of spin-orbit interaction are compared, and optimal conditions for the electric operation of electrons spins in a quantum well by a gate voltage are established. Electric spin inje

M. Matsumoto, B. Normand, T. M. Rice, M. Sigrist

Thallium copper chloride is a quantum spin liquid of S = 1/2 Cu^2+ dimers. Interdimer superexchange interactions give a three-dimensional magnon dispersion and a spin gap significantly smaller than the dimer coupling. This gap is closed by an applied hydrostatic pressure of approximately 2kbar or by a magnetic field of 5.6T, offering a unique opportunity to

Valmir C. Barbosa, Raul Donangelo, Sergio R. Souza

We study directed random graphs (random graphs whose edges are directed), and present new results on the so-called strong components of those graphs. We provide analytic and simulation results on two special classes of strong component, called cycle components and knots, which are important in random networks that represent certain computational systems.

Eytan Katzav, Moshe Schwartz

Ballistic deposition (BD) is considered to be a paradigmatic discrete growth model that represents the Kardar-Parisi-Zhang (KPZ) universality class. In this paper we question this connection by rigorously deriving a formal continuum equation from the BD microscopic rules, which deviates from the KPZ equation. In one dimension these deviations are not importa

John J. Quinn, Arkadiusz Wojs, Kyung-Soo Yi

Fractional quantum Hall (FQH) states have recently been observed at unexpected values of the filling factor nu. Here we interpret these states as a novel family of FQH states involving pairing correlations rather than Laughlin correlations among the quasiparticles (QP&#39;s). The correlations depend upon the behavior of the QP-QP pseudopotential V_QP(L&#39;)

R. Micnas, S. Robaszkiewicz, A. Bussmann-Holder

Superconductivity in the two component model of coexisting local electron pairs (hard-core charged bosons) and itinerant fermions coupled via charge exchange mechanism is discussed. The cases of isotropic s-wave and anisotropic pairing of extended s-wave and d_{x^2-y^2} symmetries are analyzed for a 2D square lattice within the BCS-mean field approximation a

Y. Ohta, T. Nakaegawa, S. Ejima

Quantum Monte Carlo (QMC) and density-matrix renormalization group (DMRG) methods are used to study the coupled spin-pseudospin Hamiltonian in one-dimension (1D) that models the charge-ordering instability of the anisotropic Hubbard ladder at quarter filling. We calculate the temperature dependence of the uniform spin susceptibility and specific heat as well

S. Viscardy, P. Gaspard

We apply the escape-rate formalism to compute the shear viscosity in terms of the chaotic properties of the underlying microscopic dynamics. A first passage problem is set up for the escape of the Helfand moment associated with viscosity out of an interval delimited by absorbing boundaries. At the microscopic level of description, the absorbing boundaries ge

M. Krishnan, S. Balasubramanian

Structural transitions and the melting behavior of crystalline poly(ethylene oxide),(CH2-CH2-O)n, (PEO) has been investigated using fully atomistic, constant pressure-constant temperature (NPT) molecular dynamics (MD) simulations. Melting of PEO proceeds in two stages; Order parameters reveal the loss of interchain orientational correlations and of chain hel

C. Bell, G. Burnell, C. W. Leung, E. J. Tarte

A thin Co/Cu/Permalloy (Ni$_{80}$Fe$_{20}$) pseudo-spin-valve structure is sandwiched between superconducting Nb contacts. When the current is passed perpendicular to the plane of the film a Josephson critical current ($I_C$) is observed at 4.2 K, in addition to a magnetoresistance (MR) of $\sim$ 0.5 % at high bias. The hysteresis loop of the spin-valve stru

V. N. Zavaritsky

I present arguments favouring linearity of the intrinsic (heating-free) I-V of the `intrinsic&#39; Josephson effect.

S. Viscardy, P. Gaspard

We report a study of viscosity by the method of Helfand moment in systems with periodic boundary conditions. We propose a new definition of Helfand moment which takes into account the minimum image convention used in molecular dynamics with periodic boundary conditions. Our Helfand-moment method is equivalent to the method based on the Green-Kubo formula and

Tobias Kramer, Christian Bracher

The propagation of electrons in static and uniform electromagnetic fields is a standard topic of classical electrodynamics. The Hamilton function is given by a quadratic polynomial in the positions and momenta. The corresponding quantum-mechanical problem has been analyzed in great detail and the eigenfunctions and time evolution operators are well-known. Su

B. A. van Tiggelen

We apply the theory of multiple wave scattering to two contemporary, related topics: imaging with diffuse correlations and stability of time-reversal of diffuse waves, using equipartition, coherent backscattering and frequency speckles as fundamental concepts.

O. Narikiyo, W. Sakikawa

By calculating the non-equilibrium parameter of the probability distribution function and the singularity spectrum of multifractal we have quantified the dynamical heterogeneity in strongly correlated many-body systems.

Akira Oguri

We show that the transmission probability through a small interacting region connected to noninteracting leads, can be written in terms of a retarded product of a three-point correlation function defined in the real time. Our proof is based on the Kubo formalism, and uses an Eliashberg theory for analytic properties of vertex functions. The aim of this short

Ivan Kupcic

The gauge invariant, two-component optical conductivity model, with a correlation gap structure related to the umklapp scattering processes, is applied to the quasi-one-dimensional electronic systems and compared to the recent measurements on the Bechgaard salt (TMTSF)_2PF_6. The optical response of both the insulating and metallic state is found for the hal

Maria K. Koleva, Valery C. Covachev

The major goal of the present paper is to find out the manifestation of the boundedness of fluctuations. Two different subjects are considered: (i) an ergodic Markovian process associated with a new type of large scaled fluctuations at spatially homogeneous reaction systems; (ii) simulated dynamical systems that posses strange attractors. Their common proper

C. J. Wellard, L. C. L. Hollenberg, F. Parisoli, L. Kettle

Inter-valley interference between degenerate conduction band minima has been shown to lead to oscillations in the exchange energy between neighbouring phosphorus donor electron states in silicon \cite{Koiller02,Koiller02A}. These same effects lead to an extreme sensitivity of the exchange energy on the relative orientation of the donor atoms, an issue of cru

S. Pleutin

We consider clean cylindrical nanostructures with an applied longitudinal static magnetic field. Without Coulomb interaction, the field induces, for particular values, points of degeneracy where a change of ground state takes place due to Aharonov-Bohm effect. The Coulomb potential introduces interaction between the electronic configurations. As a consequenc

Savvas M. Koushiappas, Andrew R. Zentner, Terrence P. Walker

We estimate the probability of detecting gamma-rays from the annihilation of neutralino dark matter in the substructure of the Milky Way. We characterize substructure statistically based on Monte Carlo realizations of the formation of a Milky Way-like halo using semi-analytic methods that have been calibrated against N-body simulations. We find that it may b

John Swain

One of the most fascinating puzzles in particle astrophysics today is that of the origin and nature of the highest energy cosmic rays. The Pierre Auger Observatory (PAO), currently under construction in Province of Mendoza, Argentina, and with another site planned in the Northern hemisphere, is a major international effort to make precise, high statistics st

G. A. Drukier, C. D. Bailyn

We estimate the number of individual, fast-moving stars observable in globular clusters under the assumption that the clusters contain massive central black holes which follow the galactic black-hole mass vs. sigma relationship. We find that radial velocity measurements are unlikely to detect such stars, but that proper motion studies could reveal such stars

Christian R. Kaiser, James J. Binney

We emphasise the importance of the gas entropy in studying the evolution of cluster gas evolving under the influence of radiative cooling. On this basis, we develop an analytical model for this evolution. We then show that the assumptions needed for such a model are consistent with a numerical solution of the same equations. We postulate that the passive coo

David Seery, Andy Taylor

The braneworld cosmology, in which our universe is imbedded as a hypersurface in a higher dimensional bulk, has the peculiar property that the inflationary consistency relation derived in a four-dimensional cosmology persists. This consistency condition relates the ratio of tensor and scalar perturbation amplitudes to the tensor spectral index produced durin

A. Bazzano, A. J. Bird, F. Capitanio, M. Del Santo

We report preliminary results of a broadband spectral and temporal study of the black-hole binary Cyg X-1 performed with the IBIS telescope. Cyg X-1 was the first pointed celestial target of IBIS during the INTEGRAL Performance and Verification Phase, 2002 Nov.-Dec., for a total observing time of 2 Ms in both staring and dithering mode. Here, we report on on

C. Burigana, R. Salvaterra

We have studied the implications of the new generation of CMB spectrum space experiments for our knowledge of the thermal history of the Universe. The combination of two experiments with the sensitivity and the frequency coverage jointly forseen for DIMES and FIRAS II will be able to greatly change our vision of the capability of the CMB spectrum information

Sujan K. Sengupta

The radiative transfer equations for multiple inverse Compton scattering of the Cosmic Microwave Background Radiation (CMBR) by the hot intra-cluster electrons are solved numerically. The spherical isothermal and inhomogeneous $β$ model has been considered for the electron distribution. The anisotropy of the CMBR caused by scattering, known as thermal Sunyae

Hongsu Kim, Hyung Mok Lee, Chul H. Lee, Hyun Kyu Lee

In association with the Goldreich-Julian&#39;s magnetic braking mechanism to explain the luminosity of radio pulsars as a result of their spin-down, it is of some interest to explore how much of magnetic flux can actually penetrate the surface of the rotating neutron stars at least in idealized situations. In order to address this issue, one needs to figure

J. Doyne Farmer, Fabrizio Lillo

In a recent Nature paper, Gabaix et al. \cite{Gabaix03} presented a theory to explain the power law tail of price fluctuations. The main points of their theory are that volume fluctuations, which have a power law tail with exponent roughly -1.5, are modulated by the average market impact function, which describes the response of prices to transactions. They

Ricardo Weder

We prove that the scattering matrix at a fixed quasi--energy determines uniquely a time--periodic potential that decays exponentially at infinity. We consider potentials that for each fixed time belong to $L^{3/2}$ in space. The exponent 3/2 is critical for the singularities of the potential in space. For this singular class of potentials the result is new e

Stefan Hollands

The 1/N expansion in quantum field theory is formulated within an algebraic framework. For a scalar field taking values in the $N$ by $N$ hermitian matrices, we rigorously construct the gauge invariant interacting quantum field operators in the sense of power series in 1/N and the `t Hooft coupling parameter as members of an abstract *-algebra. The key advan

Florian Girelli, Hendryk Pfeiffer

The term higher gauge theory refers to the generalization of gauge theory to a theory of connections at two levels, essentially given by 1- and 2-forms. So far, there have been two approaches to this subject. The differential picture uses non-Abelian 1- and 2-forms in order to generalize the connection 1-form of a conventional gauge theory to the next level.

A. V. Efremov, K. Goeke, P. Schweitzer

Predictions are made for single spin azimuthal asymmetries due to the Collins effect in pion production from semi-inclusive deeply inelastic scattering off transversely and longitudinally polarized targets for the HERMES and COMPASS experiments. The x-dependence of the asymmetries is evaluated using the parton distribution functions from the chiral quark-sol

Yasunori Nomura

We study a theory of electroweak symmetry breaking without a Higgs boson, recently suggested by Csaki et al. The theory is formulated in 5D warped space with the gauge bosons and matter fields propagating in the bulk. In the 4D dual picture, the theory appears as the standard model without a Higgs field, but with an extra gauge group G which becomes strong a

Savvas M. Koushiappas, Andrew R. Zentner, Terrence P. Walker

We estimate the probability of detecting gamma-rays from the annihilation of neutralino dark matter in dense, central regions of Milky Way substructure. We characterize Galactic substructure statistically based on Monte Carlo realizations of the formation of a Milky Way-like halo using a semi-analytic method that has been calibrated against the results of hi

Brad Jackson, Jeffrey D. Scargle, David Barnes, Sundararajan Arabhi

Many signal processing problems can be solved by maximizing the fitness of a segmented model over all possible partitions of the data interval. This letter describes a simple but powerful algorithm that searches the exponentially large space of partitions of $N$ data points in time $O(N^2)$. The algorithm is guaranteed to find the exact global optimum, autom

Dmitri Diakonov, Victor Petrov

We generalize the usual octet, decuplet and exotic antidecuplet and higher baryon multiplets to any number of colours Nc. We show that the multiplets fall into a sequence of bands with O(1/Nc) splittings inside the band and O(1)splittings between the bands characterized by &#34;exoticness&#34;, that is the number of extra quark-antiquark pairs needed to comp

Bumseok Kyae, Chin-Aik Lee, Qaisar Shafi

We consider five dimensional (5D) supersymmetric SO(10) compactified on the orbifold $S^1/(Z_2\times Z_2&#39;)$ such that the SO(10) gauge symmetry is broken on both fixed points (branes), and the residual gauge symmetry is $SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)_X$. We explore one example in which the gauge symmetries on the two branes are respective

C. Molina, D. Giugno, E. Abdalla, A. Saa

We present an exhaustive analysis of scalar, electromagnetic and gravitational perturbations in the background of Schwarzchild-de Sitter and Reissner-Nordstrom-de Sitter spacetimes. The field propagation is considered by means of a semi-analytical (WKB) approach and two numerical schemes: the characteristic and general initial value integrations. The results

Gabriel Rockefeller, Chris L. Fryer, Fulvio Melia, Michael S. Warren

Recent observations with the Chandra X-ray Observatory have provided us with the capability to discriminate point sources, such as the supermassive black hole Sgr A*, from the diffuse emission within the inner 10&#39;&#39; of the Galaxy. The hot plasma producing the diffuse X-radiation, estimated at ~7.6*10^{31} ergs s^{-1} arcsec^{-2} in the 2-10 keV band,