April 2000 arXiv papers — page 5
Showing 401–500 of 2,147 papers
Competition Between Induced Symmetry Breaking, Cooper Pairing and Chiral Condensate at Finite Density
nucl-thYoungman Kim, Mannque Rho
We study the competition between induced symmetry breaking (ISB), Cooper pairing (superconductivity) and chiral condensation at finite non-asymptotic density. Using a quantum mechanical model studied recently by Ilieva and Thirring, we analyze the expectation value of the fermion number density $\la a^*a\ra$ in the presence of chemical potential and discuss
Phung Ho Hai
We show that, with some technical conditions, an abelian category can be embedded into the category of bimodules over a ring. The case of semisimple rigid monoidal categories is studied in more detail.
Jim Bryan, Ron Donagi, Naichung Conan Leung
We study the moduli space M(G,A) of flat G-bundles on an Abelian surface A, where G is a compact, simple, simply connected, connected Lie group. Equivalently, M(G,A) is the (coarse) moduli space of s-equivalence classes of holomorphic semi-stable G_C-bundles with trivial Chern classes where G_C is the complexified group. M(G,A) has the structure of a hyperka
Razvan Gelca
In previous joint work with Frohman and Lofaro a noncommutative generalization of the A-polynomial of a knot was introduced, consisting of a finitely generated ideal of polynomials (the noncommutative A-ideal) in the quantum plane. The present paper shows that the noncommutative A-ideal of a knot, together with finitely many of its colored Jones polynomials
Dan Burns, Yi Hu, Tie Luo
We show that any birational map between projective hyperKähler manifolds of dimension 4 is composed of a sequence of simple flops or elementary Mukai transformations under the assumption that each irreducible component of the indeterminacy of the birational map is normal.
Branko Saric
Analogously to the concept of a curvature of curve and surface, in the differential geometry, in the main part of this paper the concept of the curvature of the hyper-dimensional vector spaces of Riemannian metric is generally defined. The defined concept of the curvature of Riemannian spaces of higher dimensions M: M>1, in the further text of the paper, is
Branko Saric
In the introduction part of this paper, first of all, the concept of absolute integral sum of complex function is defined, as more general one with respect to the concept of integral as well as of integral sum of "ordinary'' integral calculus. In the main part of the paper, on the basis of redefined concepts of a spatial derivative as well as of
Andrei Zelevinsky
Double Bruhat cells in a semisimple group are intersections of cells in two Bruhat decompositions corresponding to two opposite Borel subgroups. They form a geometric framework for the study of total positivity in semisimple groups; they are also closely related to symplectic leaves in the corresponding Poisson-Lie groups. The term "cells" might be m
Mauricio Cataldo, Alberto Garcia
(2+1)-regular static black hole solutions with a nonlinear electric field are derived. The source to the Einstein equations is an energy momentum tensor of nonlinear electrodynamics, which satisfies the weak energy conditions and in the weak field limit becomes the (2+1)-Maxwell field tensor. The derived class of solutions is regular; the metric, curvature i
Harald Grosse, Edwin Langmann
We find a large class of quantum gauge models with massless fermions where the coupling to the gauge fields is not chirally symmetric and which nevertheless do not suffer from gauge anomalies. To be specific we study two dimensional Abelian models in the Hamiltonian framework which can be constructed and solved by standard techniques. The general model descr
Alexander Turbiner
A certain notion of canonical equivalence in quantum mechanics is proposed. It is used to relate quantal systems with discrete ones. Discrete systems canonically equivalent to the celebrated harmonic oscillator as well as the quartic and the quasi-exactly-solvable anharmonic oscillators are found. They can be viewed as a translation-covariant discretization
Theodora Ioannidou
Atiyah and Manton have outlined a scheme to obtain approximations to the SU(2) skyrmions from instantons in $\R^4$. In this paper we apply this scheme to construct, in an explicit form, approximations to static spherically symmetric SU(N) skyrmions with various baryon numbers. In particular we show how to obtain the skyrmions from instantons using harmonic m
H. Ikemori, S. Kitakado, H. Otsu, T. Sato
Quantum mechanics on sphere $S^{n}$ is studied from the viewpoint that the Berry's connection has to appear as a topological term in the effective action. Furthermore we show that this term is the Chern-Simons term of gauge variables that correspond to the extra degrees of freedom of the enlarged space.
Nathan Berkovits, Brenno Carlini Vallilo
Using pure spinors, the superstring was recently quantized in a manifestly ten-dimensional super-Poincaré covariant manner and a covariant prescription was given for tree-level scattering amplitudes. In this paper, we prove that this prescription is cyclically symmetric and, for the scattering of an arbitrary number of massless bosons and up to four massless
A. V. Bratchikov
We use the conformal Ward identities to study the structure of correlation functions in coset conformal field theories. For a large class of primary fields of arbitrary g/h theory a factorization anzatz is found.Corresponding correlation functions are explicitly expressed in terms of correlation functions of two independent WZNW theories for g and h.
Kaushik Bhattacharya, Palash B. Pal
We calculate the cross section of the inverse beta decay process, $ν_e+n\to p+e$, in a magnetic field which is much smaller than $m_p^2/e$. Using exact solutions of the Dirac equation in a constant magnetic field, we find that the cross section depends on the direction of the incident neutrino even when the initial neutron is assumed to be at rest. We discus
M. M. Block, F. Halzen, T. Stanev
We simultaneously fit a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, together with cosmic ray data (using Glauber theory), to predict proton-air and proton-proton cross sections at energies near \sqrt s \approx 30 TeV. The p-air cosmic ray measurements provide a strong constraint
A. Widom, Y. N. Srivastava
The decay of the Higgs particle into two gravitons was previously calculated by us using a Born term from the Einstein field equations. Subsequently, others computed the same decay via one loop diagrams but omitting the Born terms. Here all of the diagrams up to one loop are discussed, and it is shown that the Born term is overwhelmingly dominant in agreemen
A. Sornborger, M. Parry
Systems that exhibit pattern formation are typically driven and dissipative. In the early universe, parametric resonance can drive explosive particle production called preheating. The fields that are populated then decay quantum mechanically if their particles are unstable. Thus, during preheating, a driven-dissipative system exists. We have shown previously
Next-to-leading Order Calculation of the Color-Octet 3S1 Gluon Fragmentation Function for Heavy Quarkonium
hep-phEric Braaten, Jungil Lee
The short-distance coefficients for the color-octet 3S1 term in the fragmentation function for a gluon to split into heavy quarkonium states is calculated to order alpha_s^2. The gauge-invariant definition of the fragmentation function by Collins and Soper is employed. Ultraviolet divergences are removed using the MS-bar renormalization procedure. The longit
H. Sazdjian
Pionium lifetime corrections to the nonrelativistic formula are calculated in the framework of the quasipotential-constraint theory approach. The calculation extends an earlier evaluation, made in the scheme of standard chiral perturbation theory, to the scheme of generalized chiral perturbation theory, in which the quark condensate is left as a free paramet
Christian Beck
We generalize Hagedorn's statistical theory of momentum spectra of particles produced in high-energy collisions using Tsallis' formalism of non-extensive statistical mechanics. Suitable non-extensive grand canonical partition functions are introduced for both fermions and bosons. Average occupation numbers and moments of transverse momenta are evalua
Peter Lichard, Julia Thompson
The rate of the beta decay of neutral kaons is calculated within the meson dominance approach taking into account the relation between the KKρand ππρcoupling constants which follows from the vector meson dominance in electromagnetic interactions and isospin symmetry. The decay rate transforms into the following branching fraction summed over the charge state
Wojciech Krolikowski
An algebraic argument based on a series of generalized Dirac equations, truncated by an "intrinsic Pauli principle", shows that there should exist two sterile neutrinos as well as three families of leptons and quarks. Then, the influence of these additional neutrinos on neutrino oscillations is studied. As an example, a specific model of effective fi
B. S. Zou, H. B. Li, representing BES Collaboration
$J/Ψ$ particles are abundantly produced at the Beijing Electron Positron Collider (BEPC). The $J/Ψ$ decays provide an excellent place for studying $N^*$ resonances. For $J/Ψ\to\bar NNπ$ and $\bar NNππ$, the $πN$ and $ππN$ systems are limited to be pure isospin 1/2 due to isospin conservation. This is a big advantage in studying $N^*$ resonances from $J/Ψ$ de
S. Chaturvedi, N. Mukunda
A unified approach to parametrization of the mixing matrix for $N$ generations is developed. This approach not only has a clear geometrical underpinning but also has the advantage of being economical and recursive and leads in a natural way to the known phenomenologically useful parametrizations of the mixing matrix.
Y. Iwasaki, K. Kanaya, S. Kaya, T. Yoshié
We study the nature of the QCD vacuum at general number of flavors $N_F$ by numerical simulations on the lattice. Combining the results with those of the perturbation theory, we propose the following picture: 1) For $N_F \ge 17$, there exists only one IR fixed point at vanishing gauge coupling, i.e., the theory in the continuum limit is trivial. 2) For $16 \
Hideo Nakajima, Sadataka Furui
The first test of the Kugo-Ojima colour confinement criterion by the lattice Landau gauge QCD simulation is performed. The parameter u which is expected to be -1δ^a_b in the continuum theory was found to be -0.7δ^a_b in the strong coupling region. The data is analyzed in connection with the theory of Zwanziger. In the weak coupling region, the expectation va
Measurements of Charm Fragmentation into $D_s^{*+}$ and $D_s^+$ in $e^+e^-$ Annihilations at $\sqrt{s}$=10.5 GeV
hep-exR. A. Briere, CLEO Collaboration
A study of charm fragmentation into $D_s^{*+}$ and $D_s^+$ in $e^+e^-$ annihilations at $\sqrt{s}$=10.5 GeV is presented. This study using $4.72 \pm 0.05$ fb$^{-1}$ of CLEO II data reports measurements of the cross-sections $σ(D_s^{*+})$ and $σ(D_s^+)$ in momentum regions above $x=0.44$, where $x$ is the $D_s$ momentum divided by the maximum kinematically al
SLD Collaboration
We present a measurement of the left-right cross-section asymmetry (ALR) for Z boson production by e+e- collisions. The measurement includes the final data taken with the SLD detector at the SLAC Linear Collider (SLC) during the period 1996-1998. Using a sample of 383,487 Z decays collected during the 1996-1998 runs we measure the pole-value of the asymmetry
I. G. Alekseev, P. E. Budkovsky, V. P. Kanavets, L. I. Koroleva
The ITEP-PNPI collaboration presents the results of the measurements of the spin rotation parameter A in the elastic scattering of positive and negative pions on protons at P_beam = 1.62 GeV/c. The setup included a longitudinally-polarized proton target with superconductive magnet, multiwire spark chambers and a carbon polarimeter with thick filter. Results
S. N. Coppersmith, Leo P. Kadanoff, Zhitong Zhang
We consider a class of models describing the dynamics of $N$ Boolean variables, where the time evolution of each depends on the values of $K$ of the other variables. Previous work has considered models with dissipative dynamics. Here we consider time-reversible models, which necessarily have the property that every possible point in the state-space is an ele
S. M. Badalyan
Carrier interaction with phonons, photons, impurities, and electrons have been addressed in semiconductor nanoscale systems with carrier confinement in one and two dimensions subjected to a quantizing magnetic field and without it.
V. A. Stephanovich
We predict the existence of Griffith phase in the dielectrics with concentrational crossover between dipole glass (electric analog of spin glass) and ferroelectricity. The peculiar representatives of above substances are $KTaO_3:Li$, $Nb$, $Na$ or relaxor ferroelectrics like $Pb_{1-x}La_xZr_{0.65}Ti_{0.35}O_3$. Since this phase exists above ferroelectric pha
Stripes ordering in self-stratification experiments of binary and ternary granular mixtures
cond-mat.softN. Lecocq, N. Vandewalle
The self-stratification of binary and ternary granular mixtures has been experimentally investigated. Ternary mixtures lead to a particular ordering of the strates which was not accounted for in former explanations. Bouncing grains are found to have an important effect on strate formation. A complementary mechanism for self-stratification of binary and terna
Small Bipolarons in the 2-dimensional Holstein-Hubbard Model. II Quantum Bipolarons
cond-mat.supr-conLaurent Proville, Serge Aubry
We study the effective mass of the bipolarons and essentially the possibility to get both light and strongly bound bipolarons in the Holstein-Hubbard model and some variations in the vicinity of the adiabatic limit. Several approaches to investigate the quantum mobility of polarons and bipolarons are proposed for this model. It is found that the bipolaron ma
Small Bipolarons in the 2-dimensional Holstein-Hubbard Model. I The Adiabatic Limit
cond-mat.supr-conLaurent Proville, Serge Aubry
The spatially localized bound states of two electrons in the adiabatic two-dimensional Holstein-Hubbard model on a square lattice are investigated both numerically and analytically. The interplay between the electron-phonon coupling g, which tends to form bipolarons and the repulsive Hubbard interaction $\upsilon \geq 0$, which tends to break them, generates
S. Sasaki, S. De Franceschi, J. M. Elzerman, W. G. van der Wiel
The Kondo effect is a key many-body phenomenon in condensed matter physics. It concerns the interaction between a localised spin and free electrons. Discovered in metals containing small amounts of magnetic impurities, it is now a fundamental mechanism in a wide class of correlated electron systems. Control over single, localised spins has become relevant al
Patrik Henelius, A. V. Balatsky, J. R. Schrieffer
We discuss the effects of magnetic impurities on d-wave superconductors. We calculate the electron mediated RKKY interaction between the impurity spins in a d-wave superconductor and find that it decays as $r^{-3}$ at large distances. We argue that this interaction leads to the formation of a spin glass at low temperature $T \ll T_c$. It was previously shown
Weak antiferromagnetism due to Dzyaloshinskii-Moriya interaction in Ba$_3$Cu$_2$O$_4$Cl$_2$
cond-mat.str-elV. Yushankhai, M. Wolf, K. -H. Mueller, R. Hayn
The antiferromagnetic insulating cuprate Ba$_3$Cu$_2$O$_4$Cl$_2$ contains folded CuO$_2$ chains with four magnetic copper ions ($S=1/2$) per unit cell. An underlying multiorbital Hubbard model is formulated and the superexchange theory is developed to derive an effective spin Hamiltonian for this cuprate. The resulting spin Hamiltonian involves a Dzyaloshins
M. Ya. Amusia, V. R. Shaginyan
In the context of the density functional theory we consider the single particle excitation spectra of electron systems. As a result, we have related the single particle excitations with the eigenvalues of the corresponding Kohn-Sham equations. In a case when the exchange correlation functional is approximated by the exchange functional the coupling equations
Raul Donangelo, Alex Hansen, Kim Sneppen, Sergio R. Souza
We consider a market where many agents trade many different types of products with each other. We model development of collective modes in this market, and quantify these by fluctuations that scale with time with a Hurst exponent of about 0.7. We demonstrate that individual products in the model occationally become globally accepted means of exchange, and si
Multiscaling at ferromagnetic-spin glass transition point of Random Energy Model and complexity
cond-mat.dis-nnD. B. Saakian
We calculate moments of free energy's finite size correction for the transition point between ferromagnetic and spin glass phases. We find, that those moments scale with the number of spins with different critical indices, characteristic for the multiscaling. This critical point corresponds to threshold of errorless coding for a gaussian noisy channel. W
Claudius Gros, Roser Valenti, J. V. Alvarez, Kay Hamacher
Recent experimental evidence suggest the existence of three distinct V-valence states (V^{+4}, V^{+4.5} and V^{+5}) in the low-temperature phase of NaV_2O_5 in apparent discrepancy with the observed spin-gap. We investigate a novel spin cluster model, consisting of weakly coupled, frustrated four-spin clusters aligned along the crystallographic b-axis that w
Keith Slevin, Tomi Ohtsuki, Tohru Kawarabayashi
The boundary condition dependence of the critical behavior for the three dimensional Anderson transition is investigated. A strong dependence of the scaling function and the critical conductance distribution on the boundary conditions is found, while the critical disorder and critical exponent are found to be independent of the boundary conditions.
Karl D. Rakos, James M. Schombert, Andrew P. Odell, Susanna Steindling
This paper presents four color narrow-band photometry of clusters A115 ($z=0.191$) and A2283 ($z=0.182$) in order to follow the star formation history of various galaxy types. Although located at similar redshifts, the two clusters display very different fractions of blue galaxies (i.e. the Butcher-Oemler effect, $f_B = 0.13$ for A115, $f_B = 0.30$ for A2283
Ramiro de la Reza, Licio da Silva, Natalia A. Drake, Marco A. Terra
First-ascent red giants with strong and very strong Li lines have just been discovered in globular clusters. Using the stellar internal prompt 7Li enrichment - mass loss scenario, we explore the possibility of 7Li enrichment in the interstellar matter of the globular cluster M3 produced by these Li-rich giants. We found that enrichment as large as 70% or mor
William F. Welsh, Edward L. Robinson, Patrick Young
We obtained R- and I-band CCD photometry of the soft X-ray transient/neutron- star binary Aql X-1 in 1998 June while it was at quiescence. We find that its light curve is dominated by ellipsoidal variations, although the ellipsoidal variations are severely distorted and have unequal maxima. After we correct for the contaminating flux from a field star locate
Agnieszka Janiuk, Bozena Czerny, Aneta Siemiginowska, Marek A. Abramowicz
We analyse the radiation pressure instability of the standard, optically thisc disc and propose it as an explanation of the obseved variability of the superluminal microquasar GRS 1915+105. The quantitave agreement with the observed outburst amplitudes is obtained under the assumption that substantial part of the energy is carried away by the jet.
Esteban Roulet
The evolution of the observational results of microlensing towards the LMC and some of the suggested interpretations to account for them are discussed. It is emphasized that the results at present are indicative of a lensing population of white dwarfs, possibly in the spheroid (not dark halo) of the Galaxy, together with the more standard backgrounds of stel
Licia Verde
Following the discovery of the CMB, the hot big-bang model has become the standard cosmological model. In this theory, small primordial fluctuations are subsequently amplified by gravity to form the large-scale structure seen today. Different theories for unified models of particle physics, lead to different predictions for the statistical properties of the
Kinematic Evidence of Minor Mergers in Normal Sa Galaxies: NGC3626, NGC3900, NGC4772 and NGC5854
astro-phMartha P. Haynes, Katherine P. Jore, Elizabeth A. Barrett, Adrick H. Broeils
BVRI and H-alpha imaging and long-slit optical spectroscopic data are presented for four morphologically normal and relatively isolated Sa galaxies, NGC3626, NGC3900, NGC4772 and NGC5854. VLA HI synthesis imaging is presented for the first 3 objects. In all 4 galaxies, evidence of kinematic decoupling of ionized gas components is found; the degree and circum
R. D. Jeffries, E. J. Totten, D. J. James
We present high resolution spectroscopy of a sample of 24 solar-type stars in the young (15-40 Myr), open cluster, NGC 2547. We use our spectra to confirm cluster membership in 23 of these stars, determine projected equatorial velocities and chromospheric activity, and to search for the presence of accretion discs. We have found examples of both fast (vsini>
G. Ostlin
I present the first results from a HST/NICMOS imaging study of the most metal-poor blue compact dwarf galaxy IZw18. The near infrared color-magnitude diagram (CMD) is dominated by two populations, one 10-20 Myr population of red super giants and one 0.5-5 Gyr population of asymptotic giant branch stars. Stars older than 1 Gyr are required to explain the obse
T. Idiart, F. Thevenin
Abundances of alpha-elements such as Ca and Mg in disk and halo stars are usually derived from equivalent widths lines measured on high resolution spectra, and assuming Local Thermodynamic Equilibrium (LTE) . In this paper, we present non-LTE differential abundances derived by computing the statistical equilibrium of CaI and MgI atoms, using high resolution
Photon acceleration in variable ultra-relativistic outflows and high-energy spectra of Gamma-Ray Bursts
astro-phAndrei Gruzinov, Peter Meszaros
MeV seed photons produced in shocks in a variable ultra-relativistic outflow gain energy by the Fermi mechanism, because the photons Compton scatter off relativistically colliding shells. The Fermi-modified high-energy photon spectrum has a non-universal slope and a universal cutoff. A significant increase in the total radiative efficiency is possible. In so
H. M. Antia, Sarbani Basu
The temporal variations of the rotation rate in the solar interior are studied using frequency splittings from Global Oscillations Network Group (GONG) data obtained during the period 1995-99. We find alternating latitudinal bands of faster and slower rotation which appear to move towards the equator with time - similar to the torsional oscillations seen at
T. Matos, L. A. Urena-Lopez
Continuing with previous works, we present a cosmological model in which dark matter and dark energy are modeled by scalar fields $Φ$ and $Ψ$, respectively, endowed with the scalar potentials $V(Φ)=V_{o}[ \cosh {(λ\sqrt{κ_{o}}Φ)}-1] $ and $\tilde{V}(Ψ)=\tilde{V_{o}}[ \sinh {(α\sqrt{κ_{o}}Ψ)}] ^β$. This model contains 95% of scalar field. We obtain that the s
A. Sedrakian, I. Wasserman
We study the perturbation modes of rotating superfluid ellipsoidal figures of equilibrium in the framework of the two-fluid superfluid hydrodynamics and Newtonian gravity. Our calculations focus on linear perturbations of background equilibria in which the two fluids move together, the total density is uniform, and the densities of the two components are pro
Mary K. Gaillard, Brent Nelson
We calculate the one-loop quantum contributions to soft supersymmetry breaking terms in the scalar potential in supergravity theories regulated à la Pauli-Villars. We find ``universal'' contributions, independent of the regulator masses and tree level soft supersymmetry breaking, that contribute gaugino masses and A-terms equal to the ``anomaly media
Daniel Boer
We investigate a helicity non-flip double transverse spin asymmetry in vector boson production in hadron-hadron scattering, which was first considered by Ralston and Soper at the tree level. It does not involve transversity functions and in principle also arises in W-boson production for which we present the expressions. The asymmetry requires observing the
C. Knigge, K. S. Long, D. W. Hoard, P. Szkody
We present the ultraviolet spectrum of the SW Sex star and nova-like variable DW UMa in an optical low state, as observed with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope (HST). The data are well described by a synthetic white dwarf (WD) spectrum with T_eff = 46,000 +/- 1000 K, log g = 7.60 +/- 0.15, v*sin(i) = 370 +/- 100 km
Critical behavior of a non-equilibrium interacting particle system driven by an oscillatory field
cond-mat.stat-mechRoberto A. Monetti, Ezequiel V. Albano
First- and second-order temperature driven transitions are studied, in a lattice gas driven by an oscillatory field. The short time dynamics study provides upper and lower bounds for the first-order transition points obtained using standard simulations. The difference between upper and lower bounds is a measure for the strength of the first-order transition
Yi-hong Gao, Gang Tian
We search for an abelian description of the Yang-Mills instantons on certain eight dimensional manifolds with the special holonomies $Spin(7)$ and SU(4). By mimicing the Seiberg-Witten theory in four dimensions, we propose a set of monopole-like equations governing the 8-dimensional U(1) connections and spinors, which are supposed to be the dual theory of th
Roy Maartens
In Randall-Sundrum-type brane-world cosmologies, the dynamical equations on the three-brane differ from the general relativity equations by terms that carry the effects of imbedding and of the free gravitational field in the five-dimensional bulk. We derive the covariant nonlinear dynamical equations for the gravitational and matter fields on the brane, and
José S. Andrade,, Sergey V. Buldyrev, Nikolay V. Dokholyan, Shlomo Havlin
We study the flow of fluid in porous media in dimensions $d=2$ and 3. The medium is modeled by bond percolation on a lattice of $L^d$ sites, while the flow front is modeled by tracer particles driven by a pressure difference between two fixed sites (``wells'') separated by Euclidean distance $r$. We investigate the distribution function of the shorte
Sidney Bludman, Matts Roos
For a flat universe presently dominated by smooth energy, either cosmological constant (LCDM) or quintessence (QCDM), we calculate the asymptotic collapsed mass fraction as function of the present ratio of smooth energy to matter energy $\mathcal R_0$. Identifying the normalized collapsed fraction as a conditional probability for habitable galaxies, we obser
I. M. Dremin, J. W. Gary
We review results on hadron multiplicities in high energy particle collisions. Both theory and experiment are discussed. The general procedures used to describe particle multiplicity in Quantum Chromodynamics (QCD) are summarized. The QCD equations for the generating functions of the multiplicity distributions are presented both for fixed and running couplin
Takashi Tamaki, Takashi Torii
We construct static and spherically symmetric particle-like and black hole solutions with magnetic or electric charge in the Einstein-Born-Infeld-dilaton system, which is a generalization of the Einstein-Maxwell-dilaton (EMD) system and of the Einstein-Born-Infeld (EBI) system. They have remarkable properties which are not seen for the corresponding solution
Hideo Kodama, Akihiro Ishibashi, Osamu Seto
In the present paper the gauge-invariant formalism is developed for perturbations of the brane-world model in which our universe is realized as a boundary of a higher-dimensional spacetime. For the background model in which the bulk spacetime is $(n+m)$-dimensional and has the spatial symmetry corresponding to the isometry group of a $n$-dimensional maximall
L. Anton
We show that a noncollapsing solution below r_c can be constructed for the dynamics of randomly forced particle interacting with a dissipative boundary. The scaling analysis predicts a divergent collision rate at the boundary for the noncollapsing solution. This prediction is tested numerically.
I. Antoniadis, E. Kiritsis, T. Tomaras
We propose a minimal embedding of the Standard Model spectrum in a D-brane configuration of type I string theory. The SU(3) color and SU(2) weak interactions arise from two different collections of branes. The model is neither grand unified nor supersymmetric but it naturally leads to the right prediction of the weak angle for a string scale of the order of
C. D. Lu, K. Ukai, M. Z. Yang
We calculate the branching ratios and CP asymmetries for B^0 to pi^+pi^-, B^+ to pi^+pi^0 and B^0 to pi^0pi^0 decays, in a perturbative QCD approach. In this approach, we calculate non-factorizable and annihilation type contributions, in addition to the usual factorizable contributions. We found that the annihilation diagram contributions are not very small
K. -I. Kondo, T. Shinohara
We show that off-diagonal gluons and off-diagonal ghosts acquire their masses dynamically in QCD if the maximal Abelian gauge is adopted. This result strongly supports the Abelian dominance in low-energy region of QCD. The mass generation is shown to occur due to ghost-anti-ghost condensation caused by attractive quartic ghost interactions within the Abelian
Soon-Tae Hong, Won Tae Kim, Young-Jai Park, Myung Seok Yoon
We study noncommutative geometry in the framework of the Batalin-Fradkin-Tyutin(BFT) scheme, which converts second class constraint system into first class one. In an open string theory noncommutative geometry appears due to the mixed boundary conditions having second class constraints, which arise in string theory with $D$-branes under a constant Neveu-Schw
S. V. Molodtsov, A. M. Snigirev, G. M. Zinovjev
The selfconsistent approach to the quark interactions in the instanton liquid is developed within the tadpole approximation calculating the basic functional integral. The effective Lagrangian obtained includes colourless scalar field interacting with quarks. The origin of this dynamical field as an interaction carrier in soft momentum region is discussed.
Jerome Benoit, Rossen Dandoloff
Using group theoretical methods we show for both the triangular and square lattices that in the continuum limit the antiferromagnetic order parameter lives on SO3 without respect of the initial lattice. For the antiferromagnetic chain we recover the Haldane decomposition. This order parameter interacts with a local gauge field rather than with a global one a
S. Hashimoto, K-I. Ishikawa, T. Onogi, M. Sakamoto
We calculate perturbative renormalization constants for the ΔB=2 four-quark operators in lattice NRQCD. Continuum operators \bar{b}γ_μ(1-γ_5)q~ \bar{b}γ_μ(1-γ_5)q and \bar{b}(1-γ_5)q~\bar{b}(1-γ_5)q, which are necessary in evaluating the mass and width differences in $B^0_{d(s)}-\bar{B}^0_{d(s)}$ systems, are matched at one-loop with corresponding lattice op
Jin Young Kim
We consider the cosmological evolution of the three-brane in the background of type IIB string theory. For two different backgrounds which give nontrivial dilaton profile we have derived the Friedman-like equations. These give the cosmological evolution which is similar to the one by matter density on the universe brane. The effective density blows up as we
Louisa A. Nolan, James S. Dunlop, Raul Jimenez
Given sufficiently deep optical spectroscopy, the age estimation of high-redshif t ($z > 1$) galaxies has been claimed to be a relatively robust process (e.g. Dunlop et al. 1996) due to the fact that, for ages $< 5$Gyr, the near-ultraviolet light of a stellar population is expected to be dominated by `well-understood' main-sequence (MS) stars. Recently,
Stephen A. Fenner
We present new intuition behind Grover's quantum search algorithm by means of a Hamiltonian. Given a black-box Boolean function f mapping strings of length n into {0,1} such that f(w) = 1 for exactly one string w, L. K. Grover describes a quantum algorithm that finds w in O(2^{n/2}) time. Farhi & Gutmann show that w can also be found in the same amount t
Richard MacKenzie
These lectures are intended as an introduction to the technique of path integrals and their applications in physics. The audience is mainly first-year graduate students, and it is assumed that the reader has a good foundation in quantum mechanics. No prior exposure to path integrals is assumed, however. The path integral is a formulation of quantum mechanics
C. S. Unnikrishnan
The formalism employing local complex amplitudes that resolved the Einstein-Podolsky-Rosen puzzle (C. S. Unnikrishnan, quant-ph/0001112) is applied to the three-particle GHZ correlations. We show that the GHZ quantum correlations can be reproduced without nonlocality.
M. Shurgalin, W. H. Parkinson, K. Yoshino, C. Schoene
Experimental apparatus and measurement technique are described for precision absorption measurements in sodium - noble gas mixtures. The absolute absorption coefficient is measured in the wavelength range from 425 nm to 760 nm with 2% uncertainty and spectral resolution of 0.02 nm. The precision is achieved by using a specially designed absorption cell with
Naftali Tishby, Fernando C. Pereira, William Bialek
We define the relevant information in a signal $x\in X$ as being the information that this signal provides about another signal $y\in \Y$. Examples include the information that face images provide about the names of the people portrayed, or the information that speech sounds provide about the words spoken. Understanding the signal $x$ requires more than just
Philip R. Page
We discuss whether a low-lying hybrid baryon should be defined as a three quark - gluon bound state or as three quarks moving on an excited adiabatic potential. We show that the latter definition becomes exact, not only for very heavy quarks, but also for specific dynamics. We review the literature on the signatures of hybrid baryons, with specific reference
Alex Kasman
Recent interest in discrete, classical integrable systems has focused on their connection to quantum integrable systems via the Bethe equations. In this note, solutions to the rational nested Bethe ansatz (RNBA) equations are constructed using the ``completed Calogero-Moser phase space'' of matrices which satisfy a finite dimensional analogue of the
Frederic Helein, Joseph Kouneiher
We discuss in this paper the canonical structure of classical field theory in finite dimensions within the {\it{pataplectic}} hamiltonian formulation, where we put forward the role of Legendre correspondance. We define the Poisson $\mathfrak{p}$-brackets and $\mathfrakω$-brackets which are the analogues of the Poisson bracket on forms. We formulate the equat
Francesco Mercuri, Paolo Piccione, Daniel V. Tausk
We investigate the problem of the stability of the number of conjugate or focal points (counted with multiplicity) along a semi-Riemannian geodesic $γ$. For a Riemannian or a non spacelike Lorentzian geodesic, such number is equal to the intersection number (Maslov index) of a continuous curve with a subvariety of codimension one of the Lagrangian Grassmanni
Feng Xu
We formulate the unitary rational orbifold conformal field theories in the algebraic quantum field theory framework. Under general conditions, we show that the orbifold of a given unitary rational conformal field theories generates a unitary modular category. Many new unitary modular categories are obtained. We also show that the irreducible representations
Daniel Goldston, C. Y. Yildirim
Assuming the Generalized Riemann Hypothesis, we obtain a lower bound within a constant factor of the conjectured asymptotic result for the second moment for primes in an individual arithmetic progression in short intervals. Previous results were averaged over all progression of a given modulus. The method uses a short divisor sum approximation for the von Ma
Diarmuid Crowley, Christine M. Escher
We classify the total spaces of bundles over the four sphere with fiber a three sphere up to orientation preserving and reversing homotopy equivalence, homeomorphism and diffeomorphism. These total spaces have been of interest to both topologists and geometers. It has recently been shown by Grove and Ziller that each of these total spaces admits metrics with
Narcisse Randrianantoanina
Let $\M$ be a semi-finite von Neumann algebra equipped with a faithful normal trace $τ$. We study the subspace structures of non-commutative Lorentz spaces $L_{p,q}(\M, τ)$, extending results of Carothers and Dilworth to the non-commutative settings. In particular, we show that, under natural conditions on indices, $\ell_p$ can not be embedded into $L_{p,q}(
Narcisse Randrianantoanina
We prove that a Banach space $E$ has the compact range property (CRP) if and only if for any given $C^*$-algebra $\cal A$, every absolutely summing operator from $\cal A$ into $E$ is compact.
Narcisse Randrianantoanina
Let $\cal M$ be a semi-finite von Neumann algebra equipped with a distinguished faithful, normal, semi-finite trace $τ$. We introduce the notion of equi-integrability in non-commutative spaces and show that if a rearrangement invariant quasi-Banach function space $E$ on the positive semi-axis is $α$-convex with constant 1 and satisfies a non-trivial lower $q
Micho Durdevich
A general theory of quantum spinor structures on quantum spaces is presented, within the conceptual framework of the formalism of quantum principal bundles. Quantum analogs of all basic objects of the classical theory are constructed and analyzed. This includes Laplace and Dirac operators, quantum versions of Clifford and spinor bundles, a Hodge *-operator,
V. Tarasov, A. Varchenko
The trigonometric KZ equations associated with a Lie algebra $\g$ depend on a parameter $λ\in\h$ where $\h\subset\g$ is the Cartan subalgebra. We suggest a system of dynamical difference equations with respect to $λ$ compatible with the KZ equations. The dynamical equations are constructed in terms of intertwining operators of $\g$-modules.
A. C. R. Mendes, W. Oliveira, F. I. Takakura
Hydrodynamic turbulence is studied as a constrained system from the point of view of metafluid dynamics. We present a Lagrangian description for this new theory of turbulence inspired from the analogy with electromagnetism. Consequently it is a gauge theory. This new approach to the study of turbulence tends to renew the optimism to solve the difficult probl
M. Gomes, L. C. Malacarne, A. J. da Silva
We study the low energy regime of the scattering of two fermionic particles carrying isospin 1/2 and interacting through a non-Abelian Chern-Simons field. We calculate the one-loop scattering amplitude for both the nonrelativistic and also for the relativistic theory. In the relativistic case we introduce an intermediate cutoff, separating the regions with l
E. Dudas, J. Mourad
The tachyon-free nonsupersymmetric string theories in ten dimensions have dilaton tadpoles which forbid a Minkowski vacuum. We determine the maximally symmetric backgrounds for the $USp(32)$ Type I string and the $SO(16)\times SO(16)$ heterotic string. The static solutions exhibit nine dimensional Poincaré symmetry and have finite 9D Planck and Yang-Mills co