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November 2003 arXiv papers — page 3

Showing 201–300 of 3,366 papers

  1. Suresh K. Maran

    This article has been replaced by gr-qc/0412011

  2. A. J. M. Medved, Damien Martin

    There is an apparent discrepancy in the literature with regard to the quasinormal mode frequencies of Schwarzschild-de Sitter black holes in the degenerate-horizon limit. On the one hand, a Poschl-Teller-inspired method predicts that the real part of the frequencies will depend strongly on the orbital angular momentum of the perturbation field whereas, on th

  3. Yuri Martinez-Raton

    The phase diagram of prolate and oblate particles in the restricted orientations approximation (Zwanzig model) is calculated. Transitions to different inhomogeneous phases (smectic, columnar, oriented, or plastic solid) are studied through minimization of the fundamental measure functional (FMF) of hard parallelepipeds. The study of parallel hard cubes (PHC&

  4. Francesco Polizzi

    We classify the minimal algebraic surfaces of general type with $p_g=q=1, K^2=8$ and bicanonical map of degree 2. It will turn out that they are isogenous to a product of curves, so that if $S$ is such a surface then there exist two smooth curves $C, F$ and a finite group $G$ acting freely on $C \times F$ such that $S = (C \times F)/G$. We describe the $C, F

  5. C. Albertus, J. E. Amaro, E. Hernandez, J. Nieves

    The use of Heavy Quark Symmetry to study bottom and charmed baryons leads to important simplifications of the non-relativistic three body problem, which turns out to be easily solved by a simple variational ansatz. Our simple scheme reproduces previous results (baryon masses, charge and mass radii, $...$) obtained by solving the Faddeev equations with simple

  6. A. Zeh, S. Klose, D. H. Hartmann

    We systematically reanalyzed all Gamma-Ray Burst (GRB) afterglow data published through the end of 2002, in an attempt to detect the predicted supernova light component and to gain statistical insight on its phenomenological properties. We fit the observed photometric light curves as the sum of an afterglow, an underlying host galaxy, and a supernova compone

  7. S. Pascazio

    The dynamical properties of a quantum system can be profoundly influenced by its environment. Usually, the environment provokes decoherence and its action on the system can often be schematized by adding a noise term in the Hamiltonian. However, other scenarios are possible: we show that by increasing the strength of the noise, the Hilbert space of the syste

  8. A A Bytsenko, V S Mendes, A C Tort

    We work with $N-$dimensional compact real hyperbolic space $X_Γ$ with universal covering $M$ and fundamental group $Γ$. Therefore, $M$ is the symmetric space $G/K$, where $G=SO_1(N,1)$ and $K=SO(N)$ is a maximal compact subgroup of $G$. We regard $Γ$ as a discrete subgroup of $G$ acting isometrically on $M$, and we take $X_Γ$ to be the quotient space by that

  9. W. Grimus, L. Lavoura

    We study leptogenesis in two seesaw models where maximal atmospheric neutrino mixing and $U_{e3} = 0$ result from symmetries. Salient features of those models are the existence of three Higgs doublets and a twofold degeneracy of the neutrino Dirac mass matrix. We find that in those models both leptogenesis and neutrinoless double beta decay depend on the sam

  10. P B Kronheimer, T S Mrowka

    Let K be a non-trivial knot in the 3-sphere and let Y be the 3-manifold obtained by surgery on K with surgery-coefficient 1. Using tools from gauge theory and symplectic topology, it is shown that the fundamental group of Y admits a non-trivial homomorphism to the group SO(3). In particular, Y cannot be a homotopy-sphere.

  11. Vadim A. Rodin, Michael H. Urin, Amand Faessler

    Making use of an identity transformation independent of a nuclear model, we represent the {\bb}-amplitude as a sum of two terms. One term accounts for most of the sensitivity of the original {\bb}-amplitude to $g'_{pp}$ for realistic $g'_{pp}\simeq 1$ (with $g'_{pp}$ being the ratio of the triplet and singlet p-p interaction strengths) and is det

  12. A. E. Dorokhov, A. E. Radzhabov, M. K. Volkov

    The electromagnetic radius of the charged pion and the transition radius of the neutral pion are calculated in the framework of the nonlocal chiral quark model. It is shown in this model that the contributions of vector mesons to the pion radii are noticeably suppressed in comparison with a similar contribution in the local Nambu--Jona-Lasinio model. The for

  13. Christos Charmousis, Jean-Francois Dufaux

    We show that the Gauss-Bonnet correction to Einstein gravity induces a gravitational tachyon mode, namely an unstable spin 2 fluctuation, in the Randall-Sundrum I model. We demonstrate that this instability is generically related to the presence of a negative tension brane in the set-up, with or without $Z_2$-symmetry across it. Indeed it is shown that the t

  14. T. D. Bakeev, E. -M. Ilgenfritz, V. K. Mitrjushkin, M. Mueller-Preussker

    In SU(2) lattice pure gauge theory we study numerically the dependence of the ghost propagator G(p) on the choice of Gribov copies in Lorentz (or Landau) gauge. We find that the effect of Gribov copies is essential in the scaling window region, however, it tends to decrease with increasing beta. On the other hand, we find that at larger beta-values very stro

  15. Wolfhard Janke, Adriaan M. J. Schakel

    The tricritical behavior of the two-dimensional $q$-state Potts model with vacancies for $1\leq q \leq4$ is argued to be encoded in the fractal structure of the geometrical spin clusters of the pure model. The close connection between the critical properties of the pure model and the tricritical properties of the diluted model is shown to be reflected in an

  16. Aditi Sen De, Ujjwal Sen, Caslav Brukner, Vladimir Buzek

    We address the question as to whether an entangled state that satisfies local realism will give a violation of the same, after entanglement swapping in a suitable scenario. We consider such possibility as a kind of superadditivity in nonclassicality. Importantly, it will indicate that checking for violation of local realism, in the state obtained after entan

  17. Christos G. Tsagas

    The gravitational collapse of a magnetised medium is investigated by studying qualitatively the convergence of a timelike family of non-geodesic worldlines in the presence of a magnetic field. Focusing on the field's tension we illustrate how the winding of the magnetic forcelines due to the fluid's rotation assists the collapse, while shear-like dis

  18. Z. Y. Wang, B. Chen, C. D. Xiong

    There are enough reasons for us to consider time as a dynamical variable or operator; but according to Pauli's argument the existence of a self-adjoint time operator is incompatible with the semi-boundedness of Hamiltonian spectrum. In this article, we study the expressions of time operator and the definitions of mean time from a general and new viewpoin

  19. V. K. Ignatovich

    The Goos-Hänchen (G-H) effect for neutron reflection from condensed matter is considered. An experiment to quantify the effect is proposed. The relation of G-H shift to the neutron coherence length is considered.

  20. W. Cassing, K. Gallmeister, C. Greiner

    We investigate transverse hadron spectra from proton+proton, deuteron+Au and Au+Au collisions at sqrt{s}=200 GeV and 17.3 GeV within the Hadron-String-Dynamics (HSD) approach which is based on quark, diquark, string and hadronic degrees of freedom as well as Pythia calculations for the high pT spectra. The comparison to experimental data on transverse mass s

  21. N. Schunck, J. Dudek, A. Gozdz, P. H. Regan

    Recent theoretical calculations predict a possible existence of nuclei with tetrahedral symmetry: more precisely, the mean-field hamiltonians of such nuclei are symmetric with respect to double point-group Td. In this paper, we focus on the neutron-rich Zirconium isotopes as an example and present realistic mean-field calculations which predict tetrahedral g

  22. Itzhak Bars, I. Y. Park

    We report on new results in Witten's cubic string field theory for the off-shell factor in the 4-tachyon amplitude that was not fully obtained explicitly before. This is achieved by completing the derivation of the Veneziano formula in the Moyal star formulation of Witten's string field theory (MSFT). We also demonstrate detailed agreement of MSFT wi

  23. A. C. Kalloniatis, S. N. Nedelko

    The domain model for the QCD vacuum has previously been developed and shown to exhibit confinement of quarks and strong correlation of the local chirality of quark modes and duality of the background domain-like gluon field. Quark fluctuations satisfy a chirality violating boundary conditions parametrized by a random chiral angle $α_j$ on the $j-th$ domain.

  24. George A. Elliott, Hanfeng Li

    We show that in the generic case the smooth noncommutative tori associated to two n by n real skew-symmetric matrices are Morita equivalent if and only if the matrices are in the same orbit of the natural SO(n, n| Z) action.

  25. A. V. Kisselev, V. A. Petrov

    We present the results on non-perturbative quantum gravity effects related to extra dimensions which can be comparable, in some cases, with the SM contributions, e.g. in lepton-lepton or lepton-nucleon scattering. The case of cosmic neutrino gravitational interaction with atmospheric nucleons is considered in detail.

  26. Kazuhiko Kuroki, Yukio Tanaka, Ryotaro Arita

    We propose that spin-triplet pairing mechanism due to disconnected Fermi surfaces proposed in our previous study [Phys. Rev. B {\bf 63} 174507 (2001)] may be at work in a recently discovered superconductor Na$_x$CoO$_2$ $\cdot y$ H$_2$O. We introduce a single band effective model that takes into account the pocket-like Fermi surfaces along with the van Hove

  27. Sumitada Onda, Tetsuya Shiromizu, Kazuya Koyama, Shoko Hayakawa

    Recently the study of braneworld on the self-gravitating D-brane has been initiated and derived the gravitational equation on the brane by holographic and geometrical projection methods. Surprisingly, in common with these two methods, the matter on the brane cannot be the source of the gravity on the brane at leading order. In this paper we will propose the

  28. Louis H. Kauffman, Sofia Lambropoulou

    This paper gives two new combinatorial topological proofs of the classification of rational tangles. Each proof rests on an elegant lemma showing that rational tangles are isotopic to canonical alternating rational tangles. The first proof defines the tangle fraction from the canonical form and uses flyping to prove invariance. The second proof defines the f

  29. V. A. Tryasuchev

    We have constructed an isobar model for the $η$-photoproduction on the proton in the energy region up to the photon lab energy $K_0 = 3$ GeV. The data base involved into the fitting procedure includes precise results for the cross section and for the $T$-asymmetry of the process $γp\toηp$ near threshold obtained at MAMI and ELSA as well as recent results for

  30. Peter Ozsvath, Zoltan Szabo

    We prove that, like the Seiberg-Witten monopole homology, the Heegaard Floer homology for a three-manifold determines its Thurston norm. As a consequence, we show that knot Floer homology detects the genus of a knot. This leads to new proofs of certain results previously obtained using Seiberg-Witten monopole Floer homology (in collaboration with Kronheimer

  31. SG Schirmer, A Kolli, DKL Oi

    We present a strategy to empirically determine the internal and control Hamiltonians for an unknown two-level system (black box) subject to various (piecewise constant) control fields when direct readout by measurement is limited to a single, fixed observable.

  32. Roman Poeschl

    This article describes different approaches to investigate the behavior of parton evolution in the proton by exploiting various aspects of the hadronic final state produced in Deep Inelastic Scattering Events at HERA.

  33. Alexander Yu. Vlasov

    Most modern classical processors support so-called von Neumann architecture with program and data registers. In present work is revisited similar approach to models of quantum processors. Deterministic programmable quantum gate arrays are considered as an example. They are also called von Neumann quantum processors here and use conditional quantum dynamics.

  34. Fedor Herbut

    The challenge of equality in the strong subadditivity inequality of entropy is approached via a general additivity of correlation information in terms of nonoverlapping clusters of subsystems in multipartite states (density operators). A family of tripartite states satisfying equality is derived.

  35. Fedor Herbut

    Measurement interaction between a measured object and a measuring instrument, if both are initially in a pure state, produces a (final) bipartite entangled state vector. The quasi-classical part of the correlations in it is connected with transmission of information in the measurement. But, prior to "reading" the instrument, there is also purely quan

  36. Dennis Bonatsos, D. Lenis, P. P. Raychev, P. A. Terziev

    The predictions for the shell structure of metal clusters of the three-dimensional q-deformed harmonic oscillator (3D q-HO), utilizing techniques of quantum groups and having the symmetry Uq(3)$\supset$SOq(3), are compared to the restrictions imposed by the periodic orbit theory of Balian and Bloch, of electrons moving in a spherical cavity. It is shown that

  37. Dennis Bonatsos, B. A. Kotsos, P. P. Raychev, P. A. Terziev

    The rotational invariance under the usual physical angular momentum of the SUq(2) Hamiltonian for the description of rotational molecular spectra is explicitly proved and a connection of this Hamiltonian to the formalism of Amal'sky is provided. In addition, a new Hamiltonian for rotational spectra is introduced, based on the construction of irreducible

  38. Sophie Laplante, Frederic Magniez

    We prove a very general lower bound technique for quantum and randomized query complexity, that is easy to prove as well as to apply. To achieve this, we introduce the use of Kolmogorov complexity to query complexity. Our technique generalizes the weighted, unweighted methods of Ambainis, and the spectral method of Barnum, Saks and Szegedy. As an immediate c

  39. Stefano Pirandola, Stefano Mancini, David Vitali, Paolo Tombesi

    We present an optomechanical system as a paradigm of three-mode teleportation network. Quantum state transfer among optical and vibrational modes becomes possible by exploiting correlations established by radiation pressure.

  40. Arach Goldar, Jean-Louis Sikorav

    We study DNA adsorption and renaturation in a water-phenol two-phase system, with or without shaking. In very dilute solutions, single-stranded DNA is adsorbed at the interface in a salt-dependent manner. At high salt concentrations the adsorption is irreversible. The adsorption of the single-stranded DNA is specific to phenol and relies on stacking and hydr

  41. Alexander Kraskov, Harald Stoegbauer, Ralph G. Andrzejak, Peter Grassberger

    We present a method for hierarchical clustering of data called {\it mutual information clustering} (MIC) algorithm. It uses mutual information (MI) as a similarity measure and exploits its grouping property: The MI between three objects $X, Y,$ and $Z$ is equal to the sum of the MI between $X$ and $Y$, plus the MI between $Z$ and the combined object $(XY)$.

  42. M. Reshetnyak, B. Steffen

    The problem of the turbulent thermal convection in the Earth's liquid core is considered. Following assumptions on decreasing of the spatial scales due to the rapid rotation, we propose the subgrid model of the eddy diffusivity, which is used in the large-scale model. This approach makes it possible to model realistic regimes with small Ekman and Rossby

  43. A. Aryshev, B. Kalinin, G. Naumenko, A. Potylitsyn

    Using the pre-bunched electron beam of 5-MeV linear accelerator the coherent Smith-Purcell radiation (CSPR) from a flat periodic target (made of conductive layers separated by dielectric gaps) in millimeter wavelength region has been investigated. The angular distribution of this radiation was measured with a narrow-band detector and experimental data agree

  44. J. Javaloyes, M. Perrin, G. L. Lippi, A. Politi

    The interaction of an atomic gas confined inside a cavity with a strong electromagnetic field is numerically and theoretically investigated in a regime where recoil effects are not negligible. The spontaneous appearance of a density grating (atomic bunching) accompanied by the onset of coherent backpropagation is found to be ruled by a continuous phase-trans

  45. T. Pohl, T. Pattard, J. M. Rost

    We present long-time simulations of expanding ultracold neutral plasmas, including a full treatment of the strongly coupled ion dynamics. Thereby, the relaxation dynamics of the expanding laser-cooled plasma is studied, taking into account elastic as well as inelastic collisions. It is demonstrated that, depending on the initial conditions, the ionic compone

  46. M. Csanad, T. Csorgo, B. Lorstad, A. Ster

    We present simultaneous, quality fits to final BRAHMS, PHENIX, PHOBOS and STAR data on particle spectra and two-particle Bose-Einstein or HBT correlations as measured in Au+Au collisions at $\sqrt{s_{NN}} = 130$ GeV. Using the Buda-Lund hydro model, the best fit is achieved when the most central 1/8th of the particle emitting volume is superheated to $T > T_

  47. A. Yu. Korchin, O. Scholten

    Corrections to the Born approximation in photo-induced strangeness production off a proton are calculated in a semi-realistic microscopic model. The vertex corrections and internal contributions to the amplitude of the $\gamma p \to K^+ \Lambda$ reaction are included on the one-loop level. Different gauge-invariant phenomenological prescriptions for the modi

  48. Dennis Bonatsos, B. A. Kotsos, P. P. Raychev, P. A. Terziev

    The rotational invariance under the usual physical angular momentum of the SUq(2) Hamiltonian for the description of rotational nuclear spectra is explicitly proved and a connection of this Hamiltonian to the formalisms of Amal'sky and Harris is provided. In addition, a new Hamiltonian for rotational spectra is introduced, based on the construction of ir

  49. L. S. Geng, H. Toki, A. Ozawa, J. Meng

    The Relativistic Mean Field (RMF) theory is applied to the analysis of ground-state properties of Ne, Na, Cl and Ar isotopes. In particular, we study the recently established proton skin in Ar isotopes and neutron skin in Na isotopes as a function of the difference between the proton and the neutron separation energy. We use the TMA effective interaction in

  50. N. A. Kudryashov

    New problem is considered that is to find nonlinear differential equations with special solutions. Method is presented to construct nonlinear ordinary differential equations with exact solution. Crucial step to the method is the assumption that nonlinear differential equations have exact solution which is general solution of the simplest integrable equation.

  51. Junta Matsukidaira, Katsuhiro Nishinari

    Recently, we have proposed a {\em Euler-Lagrange transformation} for cellular automata(CA) by developing new transformation formulas. Applying this method to the Burgers CA(BCA), we have succeeded in obtaining the Lagrange representation of the BCA. In this paper, we apply this method to multi-value generalized Burgers CA(GBCA) which include the Fukui-Ishiba

  52. Jacques Bros, Ugo Moschella

    We prove a Cauchy-type integral representation for classes of functions holomorphic in four priviledged tuboid domains of the complexified one-sheeted two-dimensional hyperboloid. From a physical viewpoint, this hyperboloid can be used for describing both the two-dimensional de Sitter and anti-de Sitter universes. For two of these tuboids, called ``the Loren

  53. Alexei A. Oblomkov, Jasper V. Stokman

    We interpret the five parameter family of Macdonald-Koornwinder polynomials as vector valued spherical functions on quantum Grassmannians.

  54. Louis H. Kauffman, Sofia Lambropoulou

    This paper is an introduction to rational tangles, rational knots and links and their applications to DNA. The paper can be read as an introduction to our more technical papers on rational tangles (math.GT/0311499) and on rational knots (math.GT/0212011). The present paper includes a self-contained account of the tangle fraction from the point of view of the

  55. Sander Dahmen

    We obtain an explicit formula for the number of Lamé equations (modulo scalar equivalence) with index $n$ and projective monodromy group of order $2N$, for given $n \in \Z$ and $N \in \N$. This is done by performing the combinatorics of the `dessins d'enfants' associated to the Belyi covers which transform hypergeometric equations into Lamé equations

  56. Julio Rubio Garcia, Francis Sergeraert

    The classical problem of algebraic models for homotopy types is precisely stated, to our knowledge for the first time. Two different natural statements for this problem are produced, the simplest one being entirely solved by the notion of SSEH-structure, due to the authors. Other tentative solutions, Postnikov towers and E_\infty-chain complexes, are conside

  57. Pedro Daniel Gonzalez Perez, Gerard Gonzalez-Sprinberg

    We study an analytically irreducible algebroid germ (X, 0) of complex singularity by considering the filtrations of its analytic algebra, and their associated graded rings, induced by the divisorial valuations associated to the irreducible components of the exceptional divisor of the normalized blow-up of the normalization (Y, 0) of (X, 0), centered at the p

  58. Aleksandar Ivić

    Let P(n) denote the largest prime factor of $n \ge 2, P(1) = 1$, and let $$ β(n) = \sum_{p|n}p, \Beta(n) = \sum_{p^α||n}αp, \Beta_1(n) = \sum_{\p^α||n}p^α$$ denote "large" additive functions. A survey of results on the functions $P(n), β(n), \Beta(n)$ and $\Beta_1(n)$ is presented, as well as some new results and open problems.

  59. Stefan Ufer

    We prove the existence of a basis of Poincare-Birkhoff-Witt type for braided Hopf algebras R generated by a braided subspace V of P(R) if the braiding on V fulfils a triangularity condition. We apply our result to pointed Hopf algebras with abelian coradical and to Nichols algebras of low dimensional simple U_q(sl_2) modules.

  60. Christian Sevenheck, Duco van Straten

    In this article we prove a rigidity theorem for lagrangian singularities by studying the local cohomology of the lagrangian de Rham complex that was introduced in math.AG/0002083. The result can be applied to show the rigidity of all open swallowtails of dimension greater or equal than two. In the case of lagrangian complete intersection singularities the la

  61. Wilhelm Winter

    We show that, if a simple $C^{*}$-algebra $A$ is topologically finite-dimensional in a suitable sense, then not only $K_{0}(A)$ has certain good properties, but $A$ is even accessible to Elliott's classification program. More precisely, we prove the following results: If $A$ is simple, separable and unital with finite decomposition rank and real rank zer

  62. Aleksandar Ivić

    A sharp asymptotic formula for the sum of reciprocals of $π(n)$ is derived, where $π(x)$ is the number of primes not exceeding $x$. This result improves the previous results of De Koninck--Ivić and L. Panaitopol.

  63. Jordan S. Ellenberg

    We show that the mod p Galois representations attached to a Q-curve E of degree d over an imaginary quadratic number field K are surjective for all p larger than some constant M_{K,d}, if E has potentially multiplicative reduction at any prime not dividing 6. The proof uses Mazur's formal immersion method, a result of Darmon and Merel on non-split modula

  64. Kenro Furutani

    We explain the topology of the space, so called, Fredholm-Lagrangian-Grassmannain and the quantity ``Maslov index'' for paths in this space based on the standard theory of Functional Analysis. Our standing point is to define the Maslov index for arbitrary paths in terms of the fundamental spectral property of the Fredholm operators, which was first r

  65. Martin Kassabov

    In this article we introduce the notion of weak identities in a group and study their properties. We show that weak identities have some similar properties to ordinary ones. We use this notion to prove that any finitely generated solvable discriminating group is abelian.

  66. Louis H. Kauffman, Sofia Lambropoulou

    This paper gives new and elementary combinatorial topological proofs of the classification of unoriented and oriented rational knots and links. These proofs are based on the known classification of alternating knots through flyping, and the calculus of continued fractions. We characterize the class of strongly invertible rational links. Rational links are of

  67. Amir Dembo, Yuval Peres, Jay Rosen, Ofer Zeitouni

    Let T(x,r) denote the first hitting time of the disc of radius r centered at x for Brownian motion on the two dimensional torus. We prove that sup_{x} T(x,r)/|log r|^2 --> 2/pi as r --> 0. The same applies to Brownian motion on any smooth, compact connected, two-dimensional, Riemannian manifold with unit area and no boundary. As a consequence, we prove a con

  68. R. Akbarpour, M. Khalkhali

    We define an equivariant $K_0$-theory for \textit{Yetter-Drinfeld} algebras over a Hopf algebra with an invertible antipode. We then show that this definition can be generalized to all Hopf-module algebras. We show that there exists a pairing, generalizing Connes' pairing, between this theory and a suitably defined Hopf algebra equivariant cyclic cohomol

  69. Apostolos Dimitriadis, Amanda W. Peet, Geoff Potvin, Simon F. Ross

    We extend the investigation of nonextremal enhancons, finding the most general solutions with the correct symmetry and charges. There are two families of solutions. One of these contains a solution with a regular horizon found previously; this previous example is shown to be the unique solution with a regular horizon. The other family generalises a previous

  70. Daniel Gottesman, John Preskill

    Horowitz and Maldacena have suggested that the unitarity of the black hole S-matrix can be reconciled with Hawking's semiclassical arguments if a final-state boundary condition is imposed at the spacelike singularity inside the black hole. We point out that, in this scenario, departures from unitarity can arise due to interactions between the collapsing

  71. Jean Alexandre

    Using a non-perturbative functional method, where the quantum fluctuations are gradually set up,it is shown that the interaction of a N=1 Wess-Zumino model in 2+1 dimensions does not get renormalized. This result is valid in the framework of the gradient expansion and aims at compensating the lack of non-renormalization theorems.

  72. D. Bazeia, M. J. dos Santos, R. F. Ribeiro

    We present a method to obtain soliton solutions to relativistic system of coupled scalar fields. This is done by examining the energy associated to static field configurations. In this case we derive a set of first-order differential equations that solve the equations of motion when the energy saturates its lower bound. To illustrate the general results, we

  73. Michael Maziashvili

    Neglecting the effect of particle production at the moment of bubble nucleation, the spectrum of created particles during the bubble expansion is evaluated in the thin-wall approximation. It is shown that the expanding thin-walled bubble makes the dominant contribution to the particle production.

  74. L. Laperashvili, H. B. Nielsen

    The aim of the present talk is to show that monopoles cannot play any role in the Standard Model (SM) and in its usual extensions up to the Planck scale: $M_{Pl}=1.22\cdot 10^{19}$ GeV, because they have a huge charge and are completely confined or screened. The possibility of the extension of the SM with Family Replicated Gauge Group (FRGG) symmetry of the

  75. Takashi Tamaki, Sugumi Kanno, Jiro Soda

    Non-uniform black strings in the two-brane system are investigated using the effective action approach. It is shown that the radion acts as a non-trivial hair of black strings. The stability of solutions is demonstrated using the catastrophe theory. The black strings are shown to be non-uniform.

  76. Y. Hoshino

    We determine the position space fermion propagator in three dimensional QED based on Ward-identity and spectral representation.There is a new type of mass singularity which governs the long distance behaviour.It leads the propagator vanish at large distance more stongly than the mass term does.This term corresponds to Dynamical mass.Momentum space proagator

  77. Hartmut Wachter

    In this article we present formulae for q-integration on quantum spaces which could be of particular importance in physics, i.e. q-deformed Minkowski space and q-deformed Euclidean space in 3 or 4 dimensions. Furthermore, our formulae can be regarded as a generalization of Jackson's q-integral to 3 and 4 dimensions and provide a new possibility for an in

  78. K. Y. Liu, Z. G. He, Y. J. Zhang, K. T. Chao

    We calculate the production cross sections for $D^{*+}D^{*-}$, $D^+D^{*-}$ and $D^+D^-$ in $e^+e^-$ annihilation through one virtual photon in the framework of perturbative QCD with constituent quarks. The calculated cross sections for $D^{*+}D^{*-}$ and $D^+D^{*-}$ production are roughly in agreement with the recent Belle data. The helicity decomposition fo

  79. A. M. Pelinson, I. L. Shapiro, J. Sola, F. I. Takakura

    The anomaly-induced inflation (modified Starobinsky model) is based on the application of the effective quantum field theory approach to the Early Universe. We present a brief general review of the model and show that it does not require a fine-tuning for the parameters of the theory or initial data, gives a real chance to meet a graceful exit to the FRW pha

  80. P. Ball, S. Khalil, E. Kou

    We analyse supersymmetric contributions to B_s mixing and their impact on mixing-induced CP asymmetries, using the mass insertion approximation. We discuss in particular the correlation of SUSY effects in the CP asymmetries of B_s -> J/psi phi and B_d -> phi K_S and find that the mass insertions dominant in B_s mixing and B_d -> phi K_S are (delta_{23}^d)_{L

  81. M. V. Chizhov

    The preliminary results of PIBETA experiment strongly suggest the presence of non V-A anomalous interactions in the radiative pion decay. We assume that they arise as a result of the exchange of new intermediate chiral spin-1 bosons which interact anomalously with matter. Their contribution into the tau-decay leads to violation of the CVC hypothesis at the s

  82. S. J. Brodsky

    I survey a number of interesting tests of quantum chromodynamics at the amplitude level which can be carried out in electron-positron annihilation and in photon-photon collisions at low energy, including measurements of fundamental processes such as timelike form factors and transition amplitudes, timelike Compton scattering, timelike photon to meson transit

  83. Jose Bernabeu, Sergio Palomares-Ruiz

    Conventional reactor neutrino experiments are dissapearance experiments, and thus have less sensitivity to small mixing angles than appearance experiments do. It has been recently shown that future reactor neutrino experiments consisiting of a near and far detector are competitive with first-generation superbeams in order to determine sin^2{2 theta_{13}} dow

  84. Bruce Knuteson

    Compelling arguments suggest the presence of new physics at energy scales that will be probed by frontier energy colliders over the next decade. Arguments for each of the many flavors of new physics that have been proposed seem much less compelling. The wide variety of experimental signatures by which new physics may manifest itself suggests the desirability

  85. V. A. Mitsou

    The Transition Radiation Tracker is a combined tracking and electron identification detector, which is part of the ATLAS Inner Detector at the CERN LHC. Tracking is carried out by drift tubes, while the interleaved radiators produce detectable X-rays when electrons traverse them. The status of the construction and quality control tests will be discussed. The

  86. B. D. Yabsley

    Recent measurements in the charm sector are reviewed, concentrating on results which are sensitive to New Physics effects. The scope of the presentation includes D0-D0bar mixing searches, a CPT / Lorentz invariance study, and a range of searches for rare and forbidden decays. Results from the BaBar, Belle, CDF, CLEO, and FOCUS collaborations are presented, i

  87. Saverio Braccini

    A remarkable number of studies have been performed at LEP in the field of two-photon physics in the last four years. These results represent a very important contribution to the understanding of strong interactions at low energies. In particular, significant deviations from QCD predictions are found in the cross sections of inclusive single particle, jet and

  88. Joan Josep Ferrando Juan Antonio Sáez

    We analyze the spacetimes admitting a direction for which the relative electric and magnetic Weyl fields are aligned. We give an invariant characterization of these metrics and study the properties of its Debever null vectors. The directions 'observing' aligned electric and magnetic Weyl fields are obtained for every Petrov type. The results on the n

  89. Marcello Ortaggio

    We investigate the ultrarelativistic boost of a Schwarzschild black hole immersed in an external electromagnetic field, described by an exact solution of the Einstein-Maxwell equations found by Ernst (the ``Schwarzschild-Melvin'' metric). Following the classical method of Aichelburg and Sexl, the gravitational field generated by a black hole moving `

  90. Jacob D. Bekenstein

    Measurements of the mass or angular momentum of a black hole are onerous, particularly if they have to be frequently repeated, as when one is required to transform a black hole to prescribed parameters. Irradiating a black hole of the Kerr-Newman family with scalar or electromagnetic waves provides a way to drive it to prescribed values of its mass, charge a

  91. A. A. Blinkouski, A. K. Gorbatsievich

    A homogeneous and isotropic model of the Universe is considered in the framework of the five-dimensional Projective Unified Field Theory in which the gravitation is described by both space-time curvature and some hypothetical scalar field (sigma-field). We propose a generation method for obtaining exact solutions. New exact Friedmann-like solutions for a dus

  92. Milenko Petrovic, Mokhtar Aboelaze

    TCP is the De facto standard for connection oriented transport layer protocol, while UDP is the De facto standard for transport layer protocol, which is used with real time traffic for audio and video. Although there have been many attempts to measure and analyze the performance of the TCP protocol in wireless networks, very few research was done on the UDP

  93. Deept Kumar, Naren Ramakrishnan, Malcolm Potts, Richard F. Helm

    We present an unusual algorithm involving classification trees where two trees are grown in opposite directions so that they are matched at their leaves. This approach finds application in a new data mining task we formulate, called "redescription mining". A redescription is a shift-of-vocabulary, or a different way of communicating information about

  94. Ioana Burcea, Milenko Petrovic, Hans-Arno Jacobsen

    In recent years, the amount of information on the Internet has increased exponentially developing great interest in selective information dissemination systems. The publish/subscribe paradigm is particularly suited for designing systems for routing information and requests according to their content throughout wide-area network of brokers. Current publish/su

  95. Jan Odelstad, Magnus Boman

    An abstract architecture for idealized multi-agent systems whose behaviour is regulated by normative systems is developed and discussed. Agent choices are determined partially by the preference ordering of possible states and partially by normative considerations: The agent chooses that act which leads to the best outcome of all permissible actions. If an ac

  96. J Gerard Wolff

    This paper describes a novel approach to grammar induction that has been developed within a framework designed to integrate learning with other aspects of computing, AI, mathematics and logic. This framework, called "information compression by multiple alignment, unification and search" (ICMAUS), is founded on principles of Minimum Length Encoding pi

  97. Alberto Pettorossi, Maurizio Proietti, Sophie Renault

    Program specialization is a program transformation methodology which improves program efficiency by exploiting the information about the input data which are available at compile time. We show that current techniques for program specialization based on partial evaluation do not perform well on nondeterministic logic programs. We then consider a set of transf

  98. F. Fioravanti, A. Pettorossi, M. Proietti

    We present a program synthesis method based on unfold/fold transformation rules which can be used for deriving terminating definite logic programs from formulas of the Weak Monadic Second Order theory of one successor (WS1S). This synthesis method can also be used as a proof method which is a decision procedure for closed formulas of WS1S. We apply our synth

  99. Adam R. Klivans, Rocco A. Servedio

    We make progress on two important problems regarding attribute efficient learnability. First, we give an algorithm for learning decision lists of length $k$ over $n$ variables using $2^{\tilde{O}(k^{1/3})} \log n$ examples and time $n^{\tilde{O}(k^{1/3})}$. This is the first algorithm for learning decision lists that has both subexponential sample complexity

  100. Juergen Schmidhuber

    Most traditional artificial intelligence (AI) systems of the past 50 years are either very limited, or based on heuristics, or both. The new millennium, however, has brought substantial progress in the field of theoretically optimal and practically feasible algorithms for prediction, search, inductive inference based on Occam's razor, problem solving, de