October 1999 arXiv papers — page 8

Johannes Berg

Using methods from the statistical mechanics of disordered systems we analyze the properties of bimatrix games with random payoffs in the limit where the number of pure strategies of each player tends to infinity. We analytically calculate quantities such as the number of equilibrium points, the expected payoff, and the fraction of strategies played with non

J. Solyom, J. Zittartz

We construct a new spin-1 model on a chain. Its ground state is determined exactly which is three-fold degenerate by breaking translational invariance. Thus we have trimerization. Excited states cannot be obtained exactly, but we determine a few low-lying ones by using trial states, among them solitons.

D. Petit, L. Fruchter, I. A. Campbell

Torque, torque relaxation, and magnetization measurements on a AuFe spin glass sample are reported. The experiments carried out up to 7 T show a transverse irreversibility line in the (H,T) plane up to high applied fields, and a distinct strong longitudinal irreversibility line at lower fields. The data demonstrate for that this type of sample, a Heisenberg

A. Billoire, E. Marinari

We discuss temperature chaos in mean field and realistic 3D spin glasses. Our numerical simulations show no trace of a temperature chaotic behavior for the system sizes considered. We discuss the experimental and theoretical implications of these findings.

K. Oerding, F. van Wijland, J. -P. Leroy, H. J. Hilhorst

We present the first example of a phase transition in a nonequilibrium steady-state that can be argued analytically to be first order. The system of interest is a two-species reaction-diffusion problem whose control parameter is the total density ρ. Mean-field theory predicts a second-order transition between two stationary states at a critical density ρ=ρ_c

I. Luk'yanchuk

In a recent letter, (Phys. Rev. Lett. 82, 2892(1999); cond-mat/9808306) Kamien and Lubensky calculated the energy of the surface constructed via a linear superposition of screw dislocations in SmA phase, and obtained the positive (repulsive) sign of the long-range interaction between dislocations. We would like to object that this interaction is attractive.

Xuean Zhao, Jian Wang, Hong Guo

We report a detailed theoretical investigation on electrochemical capacitance of a nanoscale capacitor where there is a DC coupling between the two conductors. For this ``leaky'' quantum capacitor, we have derived general analytic expressions of the linear and second order nonlinear electrochemical capacitance within a first principles quantum theory

H. Imai, Y. Shimakawa, Yu. V. Sushko, Y. Kubo

Hall resistivity and magneto-thermopower have been measured for colossal magnetoresistive Tl2Mn2O7 over wide temperature and magnetic-field ranges. These measurements revealed that a small number of free electron-like carriers is responsible for the magneto-transport properties. In contrast to perovskite CMR materials, the anomalous Hall coefficient is negli

J. O. Sofo, G. D. Mahan

Opals are structures composed of the closed packing of spheres in the size range of nano-to-micro meter. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the termal and electrical conductivity makes possible to estimate the transport c

Scott J. Kenyon, E. A. Kolotilov, M. A. Ibragimov, J. A. Mattei

We analyze new and published optical photometric data of FU Orionis, an eruptive pre-main sequence star. The outburst consists of a 5.5 mag rise at B with an e-folding timescale of roughly 50 days. The rates of decline at B and V are identical, 0.015 +- 0.001 mag per yr. Random fluctuations superimposed on this decline have an amplitude of 0.035 +- 0.005 mag

P. C. Frisch

The definition of nearby star systems is incomplete without an understanding of the dynamical interaction between the stars and ambient interstellar material. The Sun itself has been immersed in the Local Bubble interior void for millions of years, and entered the outflow of interstellar material from the Scorpius-Centaurus Association within the past $\sim1

P. C. Frisch

The interstellar cloud surrounding the solar system regulates the galactic environment of the Sun and constrains the physical characteristics of the interplanetary medium. This paper compares interstellar dust grain properties observed within the solar system with dust properties inferred from observations of the cloud surrounding the solar system. Propertie

J. M. Wrobel

The NRAO VLA and VLBA were used from 1988 November to 1998 June to monitor the radio continuum counterpart to the optical broad line region (BLR) in the Seyfert galaxy NGC 5548. Photometric and astrometric observations were obtained at 21 epochs. The radio nucleus appeared resolved, so comparisons were limited to observations spanning 10-60 days and 3-4 yr,

Eva K. Grebel, You-Hua Chu

We present Hubble Space Telescope Planetary Camera UVI data for the little-studied cluster Hodge 301 3&#39; northwest of 30 Doradus&#39; central ionizing cluster R136. The average reddening of Hodge 301 is found to be <E(B-V)> = (0.28+-0.05) mag from published infrared and ultraviolet photometry. Using two different sets of evolutionary models, we derive an

Eric M. Schlegel

Optical spectra of SN1994W in NGC 4041 revealed the presence of a dense (N_e > 10^8 cm^-3) circumstellar shell. An observation with the ROSAT HRI detected a source, with a 0.2-2.4 keV luminosity of ~8x10^39 erg/sec, coincident with the position of SN1994W to within 1&#39;&#39;.4. The positional coincidence plus the optical evidence for a dense circumstellar

F. Varadi, R. K. Ulrich, L. Bertello, C. J. Henney

In a previous paper (Varadi et al., 1999), Random Lag Singular Spectrum Analysis was offered as a tool to find oscillations in very noisy and long time series. This work presents a generalization of the technique to search for common oscillations in two or more time series.

Chris J. Willott, Steve Rawlings, Matt J. Jarvis

We present near-infrared spectroscopy and imaging of the compact steep- spectrum radio source 3C 318 which shows it to be a quasar at redshift z=1.574 (the z=0.752 value previously reported is incorrect). 3C 318 is an IRAS, ISO and SCUBA source so its new redshift makes it the most intrinsically luminous far-infrared (FIR) source in the 3C catalogue (there i

Duncan A. Forbes, G. K. T. Hau

We present wide field-of-view near-infrared imaging from the NTT and very deep optical imaging from the HST of the young merging galaxy NGC 3597. The morphology of the galaxy and the properties of the newly formed proto-globular clusters (PGCs) are examined. Our K band data reveals the presence of a second nucleus, which provides further evidence that NGC 35

Namir E. Kassim, T. Joseph W. Lazio

We report a search for radio continuum emission from the gamma-ray pulsar Geminga. We have used the VLA to image the location of the optical counterpart of Geminga at 74 and 326 MHz. We detect no radio counterpart. We derive upper limits to the pulse-averaged flux density of Geminga, taking diffractive scintillation into account. We find that diffractive sci

L. Stanghellini, R. A. Shaw, J. C. Blades, B. Balick

Studies of the relationship between planetary nebula morphology and the evolution of the central stars has long suffered from uncertainties in distance determinations, and from the bias of interstellar absorption, that are typical for Galactic PNe. We will be able to eliminate the distance errors and be assured of the sample homogeneity by studying Large Mag

Patrick Godon, Mario Livio

We carry out a two-dimensional, compressible, simulation of a disk, including dust particles, to study the formation and role of vortices in protoplanetary disks. We find that anticyclonic vortices can form out of an initial random perturbation of the vorticity field. Vortices have a typical decay time of the order of 50 orbital periods (for a viscosity para

M. Blazejowski, M. Sikora, R. Moderski, T. Bulik

We study the dependence of nonthermal radiation spectra in OVV quasars on location of the low energy break in the electron/positron injection function. We show that the high energy spectra produced during the outbursts are presumably superposed from two components, one resulting from Comptonization of emission lines, which dominates at MeV-GeV energies, and

F. H. Briggs

A Square Kilometer Array radio telescope will detect tens of thousands of galaxies per square degree in the 21cm emission line of neutral hydrogen. The telescope will be sensitive to ordinary galaxy populations at redshifts z>3 when the mass density in neutral gas greatly exceeded the mass in luminous stars. Spectroscopy in the HI line will trace the kinemat

J. F. Macias-Perez, P. Helbig, R. Quast, A. Wilkinson

We present constraints on the cosmological constant lambda_0 and the density parameter Omega_0 from joint constraints from the analyses of gravitational lensing statistics of the Jodrell Bank-VLA Astrometric Survey (JVAS), optical gravitational lens surveys from the literature and CMB anisotropies. This is the first time that quantitative joint constraints i

Sabrina De Grandi, Silvano Molendi

We present results from a BeppoSAX observation of the rich cluster Abell 3266. The broad band spectrum (2-50 keV) of the cluster, when fitted with an optically thin thermal emission model, yields a temperature of 8.1 +/- 0.2 keV and a metal abundance of 0.17 +/- 0.02 in solar units, and with no evidence of a hard X-ray excess in the PDS spectrum. By performi

Jens Woitas, Christoph Leinert, Hartmut Jahreiß, Todd Henry

We present an improved orbit determination for the visual pair in the M-dwarf triple system Gliese 866 that is based on new speckle-interferometric and HST observations. The system mass is M = 0.34 +- 0.03 solar masses. The masses of the components derived using the mass-luminosity relation are consistent with this mass sum. All three components of Gliese 86

Takamitsu Miyaji, Guenther Hasinger, Maarten Schmidt

We investigate the evolution of the 0.5-2 keV soft X-ray luminosity function (SXLF) of active galactic nuclei (AGN) using results from ROSAT surveys of various depth, ranging from shallow large-area ROSAT All-Sky Survey -based samples to the deepest pointed observation on the Lockman Hole. As previously found, the SXLF evolves rapidly as a function of redshi

J. Liske, J. K. Webb, G. M. Williger, A. Fernandez-Soto

The spatial distribution of Ly-alpha forest absorption systems towards ten QSOs has been analysed to search for large-scale structure over the redshift range 2.2 < z < 3.4. The QSOs form a closely spaced group on the sky and are concentrated within a 1 deg^2 field. We have employed a technique based on the first and second moments of the transmission probabi

D. Elbaz, C. J. Cesarsky, D. Fadda, H. Aussel

We present the results of the five mid-IR 15 microns (12-18 microns LW3 band) ISOCAM Guaranteed Time Extragalactic Surveys performed in the regions of the Lockman Hole and Marano Field. The roughly 1000 sources detected, 600 of which have a flux above the 80 % completeness limit, guarantee a very high statistical significance for the integral and differentia

J. S. Gallagher, C. J. Conselice, N. Homeier, The WFPC2 Investigation Definition Team

Nearby (D < 100 Mpc) luminous blue starburst galaxies frequently show morphological evidence for recent involvement in mild collisions, or minor mergers where the disk survives. As a consequence UV-bright starbursts are preferentially seen in near face-on galaxies, and the postburst systems may become star-forming late-type galaxies. If this starburst evolut

K. Sengupta, N. Dupuis

We derive the effective action describing the long-wavelength low-energy collective modes of quasi-one-dimensional spin-density-wave (SDW) systems, starting from the Hubbard model within weak coupling approximation. The effective action for the spin-wave mode corresponds to an anisotropic non-linear sigma model together with a Berry phase term. We compute th

A. Kehagias, E. Kiritsis

A brane universe moving in a curved higher dimensional bulk space is considered. The motion induces a cosmological evolution on the universe brane that is indistiguishable from a similar one induced by matter density on the brane. The phenomenological implications of such an idea are discussed. Various mirage energy densities are found, corresponding to dilu

P. A. M. van Hoof, G. C. Van de Steene, D. A. Beintema, P. G. Martin

In this paper we study new infrared spectra of the evolved planetary nebula NGC 6445 obtained with ISO. These data show that the thermal emission from the grains is very cool and has a low flux compared to H beta. A model of the ionized region is constructed, using the photo-ionization code CLOUDY 90.05. Based on this model, we show from depletions in the ga

Michael R. Douglas

We discuss the general theory of D-branes on Calabi-Yaus, recent results from the theory of boundary states, and new results on the spectrum of branes on the quintic CY. (Contribution to the proceedings of Strings &#39;99 in Potsdam, Germany.)

An Min Wang

An universal quantum network which can implement a general quantum computing is proposed. In this sense, it can be called the quantum central processing unit (QCPU). For a given quantum computing, its realization of QCPU is just its quantum network. QCPU is standard and easy-assemble because it only has two kinds of basic elements and two auxiliary elements.

Gregory M. Harry, Insik Jin, Ho Jung Paik, Thomas R. Stevenson

We report on the total noise from an inductive motion transducer for a gravitational-wave antenna. The transducer uses a two-stage SQUID amplifier and has a noise temperature of 1.1 mK, of which 0.70 mK is due to back-action noise from the SQUID chip. The total noise includes thermal noise from the transducer mass, which has a measured Q of 2.60 X 10^6. The

Andrzej Drzewinski, Jacek Wojtkiewicz

We calculate the fourth-order cumulant ratio (proposed by Binder) for the two-dimensional Ising model in a strip geometry L x oo. The Density Matrix Renormalization Group method enables us to consider typical open boundary conditions up to L=200. Universal scaling functions of the cumulant ratio are determined for strips with parallel as well as opposing sur

A. Zheludev, S. Maslov, T. Yokoo, J. Akimitsu

Inelastic neutron scattering experiments on Nd2BaNiO5 single-crystals and powder samples are used to study the dynamic coupling of 1-dimensional Haldane-gap excitations in the S=1 Ni2+ -chains to local crystal-field transitions, associated with the rare earth ions. Substantial interference between the two types of excitations is observed even in the 1-dimens

E. Kh. Akhmedov, A. Yu. Smirnov

We show that the conditions for total neutrino conversion found in [1] are equivalent to the conditions of maximal depth (parametric resonance) and ($π/2 + πk$) - phase of parametric oscillations. Therefore the effects considered in [1] are a particular case of the parametric resonance in neutrino oscillations. The existence of strong enhancement peaks in tr

Karol Zyczkowski, Hans-Juergen Sommers

We analyze properties of non-hermitian matrices of size M constructed as square submatrices of unitary (orthogonal) random matrices of size N>M, distributed according to the Haar measure. In this way we define ensembles of random matrices and study the statistical properties of the spectrum located inside the unit circle. In the limit of large matrices, this

C. Callegari, A. Conjusteau, I. Reinhard, K. K. Lehmann

We present a superfluid hydrodynamic model for the increase in moment of inertia, $ΔI$, of molecules rotating in liquid $^4$He. The static inhomogeneous He density around each molecule (calculated using the Orsay-Paris liquid $^4$He density functional) is assumed to adiabatically follow the rotation of the molecule. We find that the $ΔI$ values created by th

C. Cartier, E. J. Copeland, R. Madden

We re-examine the graceful exit problem in the pre-big bang scenario of string cosmology, by considering the most general time-dependent classical correction to the Lagrangian with up to four derivatives. By including possible forms for quantum loop corrections we examine the allowed region of parameter space for the coupling constants which enable our solut

Michael Frank

The local multiplier C*-algebra M_{loc}(A) of any C*-algebra A can *-isomorphicly embedded into the injective envelope I(A) of A in such a way that the canonical embeddings of A into both these C*-algebras are identified. If A is commutative then M_{loc}(A) = I(A) . The injective envelopes of A and M_{loc}(A) always coincide, and every higher order local mul

Mauricio Bellini

I study a stochastic approach for warm inflation considering back - reaction of the metric with the fluctuations of matter field. This formalism takes into account the local inhomogeneities fo the spacetime in a globally flat Friedmann - Robertson - Walker metric. The stochastic equations for the fluctuations of the matter field and the metric are obtained.

V. H. Nguyen, X. Y. Pham

We discuss the electroweak gauge symmetry breaking triggered by a new strong attractive interaction to condensate fermion-antifermion, and topcolor is a prototype. To deal with the fermion pairing, a general method based on the Hubbard-Stratonovich transformation in the functional integral approach is used. We derive a formula which relates the $W^\pm$, $Z^0

R. Knorren, K. H. Bennemann, R. Burgermeister, M. Aeschlimann

Both theoretical and experimental results for the dynamics of photoexcited electrons at surfaces of Cu and the ferromagnetic transition metals Fe, Co, and Ni are presented. A model for the dynamics of excited electrons is developed, which is based on the Boltzmann equation and includes effects of photoexcitation, electron-electron scattering, secondary elect

G. de Berredo-Peixoto, J. A. Helayel-Neto, I. L. Shapiro

We discuss the possibility to construct an effective quantum field theory for an axial vector coupled to a Dirac spinor field. A massive axial vector describes antisymmetric torsion. The consistency conditions include unitarity and renormalizability in the low-energy region. The investigation of the Ward identities and the one- and two-loop divergences indic

Osamu Yasuda

Using the result of the three flavor analysis of the old Kamiokande data, the recent Superkamiokande data of atmospheric neutrinos and the CHOOZ reactor data, it is shown that the third mixing angle $θ_{13}$ is small. It is proposed to determine the small value of $θ_{13}$ and the CP violating phase $δ$ in very long baseline experiments by measuring the appe

Bernd A. Berg, Alain Billoire, Wolfhard Janke

For the Edwards-Anderson Ising spin-glass model in three and four dimensions (3d and 4d) we have performed high statistics Monte Carlo calculations of those free-energy barriers $F^q_B$ which are visible in the probability density $P_J(q)$ of the Parisi overlap parameter $q$. The calculations rely on the recently introduced multi-overlap algorithm. In both d

David H. Adams

In the continuum, a topological obstruction to the vanishing of the non-abelian anomaly in 2n dimensions is given by the index of a certain Dirac operator in 2n+2 dimensions, or equivalently, the index of a 2-parameter family of Dirac operators in 2n dimensions. In this paper an analogous result is derived for chiral fermions on the lattice in the Overlap fo

Barry R. Holstein, D. Drechsel, B. Pasquini, M. Vanderhaeghen

Compton scattering results are used to probe proton structure via measurement of higher order polarizabilities. Values for $α_{E2}^p,β_{E2}^p,α_{Eν}^p,$ $β_{Eν}^p$ determined via dispersion relations are compared to predictions based upon chiral symmetry and from the constituent quark model. Extensions to spin-polarizabilities are also discussed.

I. Nandori, J. Polonyi, K. Sailer

The renormalization of the periodic potential is investigated in the framework of the Euclidean one-component scalar field theory by means of the differential RG approach. Some known results about the sine-Gordon model are recovered in an extremely simple manner. There are two phases, an ordered one with asymptotical freedom and a disordered one where the mo

J. Denef, F. Loeser

We associate canonical virtual motives to definable sets over a field of characteristic zero. We use this construction to show that very general p-adic integrals are canonically interpolated by motivic ones.

D. K. Park, H. J. W. Müller-Kirsten, J. Q. Liang

Following our earlier investigations we examine the quantum-classical winding number transition in the Abelian-Higgs system. It is demonstrated that the sphaleron transition in this system is of the smooth second order type in the full range of parameter space. Comparison of the action of classical vortices with that of the sphaleron supports our finding.

A. Honecker, M. Kaulke, K. D. Schotte

CsCuCl_3 is a ferromagnetically stacked triangular spin-1/2 antiferromagnet. We discuss models for its zero-temperature magnetization process. The models range from three antiferromagnetically coupled ferromagnetic chains to the full three-dimensional situation. The situation with spin-1/2 is treated by expansions around the Ising limit and exact diagonaliza

K. Hasebe, Y. Sumino

A nonrelativistic boundstate formalism used in contemporary calculations is investigated. It is known that the effective Hamiltonian of the boundstate system depends on the choice of gauge. We obtain the transformation charge Q of the Hamiltonian for an arbitrary infinitesimal change of gauge, by which gauge independence of the mass spectrum and gauge depend

Karol Zyczkowski

Dynamics of a periodically time dependent quantum system is reflected in the features of the eigenstates of the Floquet operator. Of the special importance are their localization properties quantitatively characterized by the eigenvector entropy, the inverse participation ratio or the eigenvector statistics. Since these quantities depend on the choice of the

Shu-Kun Lin

The diversity of the symbols of the information source is calculated following the definition that entropy is the information loss and following a new entropy-symbol similarity relation after the rejection of the Gibbs paradox statement. Diversity in a range of 0 to 1, an index similar to Shannon&#39;s redundancy, decreases with the increase in the species s

W. Broniowski, W. Florkowski, B. Hiller

Two examples of ``exotic&#39;&#39; phenomena which become possible and important in the presence of nuclear matter are discussed: omega -> pi pi decay, and rho-omega mixing. Significance of these processes for the low-mass dilepton production in relativistic heavy-ion collisions is indicated.

Claus Hertling

Manifolds with a commutative and associative multiplication on the tangent bundle are called F-manifolds if a unit field exists and the multiplication satisfies a natural integrability condition. They are studied here. They are closely related to discriminants and Lagrange maps. Frobenius manifolds are F-manifolds. As an application a conjecture of Dubrovin

John B. Etnyre, Ko Honda

We exhibit a 3-manifold which admits no tight contact structure.

Maria Gorelik

We define a notion of ghost centre of a Lie superalgebra g=g_0+g_1 which is a sum of invariants with respect to the usual adjoint action (centre) and invariants with respect to a twisted adjoint action (``anticentre&#39;&#39;). We calculate the anticentre in the case when the top external degree of g_1 is a trivial g_0-module. We describe the Harish-Chandra

Henrique Bursztyn, Stefan Waldmann

Motivated by deformation quantization we consider $^*$-algebras over ordered rings and their deformations: we investigate formal associative deformations compatible with the $^*$-involution and discuss a cohomological description in terms of a Hermitian Hochschild cohomology. As an ordered ring allows for a meaningful definition of positive functionals and a

S. V. Ludkovsky

Gaussian quasi-invariant measures on groups of diffeomorphisms and loop groups G relative to dense subgroups G&#39; were constructed. In the non-Archimedean case the wider class of measures was investigated, than in the real case. The cases of Riemann and non-Archimedean manifolds were considered. This article is related with unitary representations of G&#39

Eugene Polulyakh

Let $\{V_{i}\}_{i=1}^{n}$ be a finite family of closed subsets of a plane or a sphere $S^{2}$, each homeomorphic to the two-dimensional disk. In this paper we discuss the question how the boundary of connected components of a complement $\rr^{2} \setminus \bigcup_{i=1}^{n} V_{i}$ (accordingly, $S^{2} \setminus \bigcup_{i=1}^{n} V_{i}$) is arranged. It appear

Zinovy Reichstein, Boris Youssin

Let $G$ be an algebraic group, $X$ a generically free $G$-variety, and $K=k(X)^G$. A field extension $L$ of $K$ is called a splitting field of $X$ if the image of the class of $X$ under the natural map $H^1(K, G) \mapsto H^1(L, G)$ is trivial. If $L/K$ is a (finite) Galois extension then $\Gal(L/K)$ is called a splitting group of $X$. We prove a lower bound

Robert L. Karp, Freydoon Mansouri, Jung S. Rno

We make use of the properties of product integrals to obtain a surface product integral representation for the Wilson loop operator. The result can be interpreted as the non-abelian version of Stokes&#39; theorem.

Duiliu-Emanuel Diaconescu, Christian Romelsberger

We study the D-brane spectrum on a two-parameter Calabi-Yau model. The analysis is based on different tools in distinct regions of the moduli space: wrapped brane configurations on elliptic fibrations near the large radius limit, and SCFT boundary states at the Gepner point. We develop an explicit correspondence between these two classes of objects, suggesti

Dmitri Gal&#39;tsov, Richard Kerner

It is shown that the Born-Infeld-type modification of the quadratic Yang-Mills action suggested by the superstring theory gives rise to classical particle-like solutions prohibited in the standard Yang-Mills theory. This becomes possible due to the scale invariance breaking by the Born-Infeld non-linearity. New classical glueballs are sphaleronic in nature a

Sergei V. Bashinsky

We generalize effective energy variational techniques to study appropriately quantized solitonic field configurations. Our approach rests on collective quantization ideas and is specifically designed for the numerical evaluation of soliton parameters. We employ this method to obtain the one-loop quantum corrections to the soliton mass and form factor. Specia

A. Rivero

The well known operator ordering ambiguity could motivate the existence of generations. This possibility is explored by exploiting the relationship between ordering and discretization rules. Context is drawn from lattice theory and non commutative geometry.

Jifeng Yang

A new attempt is demonstrated that QFTs can be UV finite if they are viewed as the low energy effective theories of a fundamental underlying theory (complete and well-defined in all respects) according to the modern standard point of view. This approach is much simpler in principle and in technology comparing to any known renormalization program. Some subtle

J. Gasser, V. E. Lyubovitskij, A. Rusetsky

We apply Chiral Perturbation Theory at one loop to analyze the general formula for the pi+pi- atom lifetime derived recently in the framework of QCD. The corresponding analytic expression is investigated numerically, and compared with recent work in the literature.

Daniel J. H. Chung, Edward W. Kolb, Antonio Riotto, Igor I. Tkachev

The phenomenon of resonant production of particles {\it after} inflation has received much attention in the past few years. In a new application of resonant production of particles, we consider the effect of a resonance {\em during} inflation. We show that if the inflaton is coupled to a massive particle, resonant production of the particle during inflation

T. Csorgo, D. Kharzeev, S. E. Vance

The intercept parameter of the two-pion Bose-Einstein correlation functions at low transverse momentum is shown to play the role of an experimentally accessible measure of the (partial) restoration of U_A(1) symmetry in ultra-relativistic nuclear collisions.

M. A. Ivanov, P. Santorelli

A relativistic constituent quark model is adopted to give an unified description of the leptonic and semileptonic decays of pseudoscalar mesons (π, K, D, D_s, B, B_s). The calculated leptonic decay constants and form factors are found to be in good agreement with available experimental data and the results of other approaches. Eventually, the model is found

M. Braun, G. P. Vacca

Using the results recently obtained for the non-forward quark and gluon impact factors, it is shown that their form in the gluon colour channel is consistent with the ``third bootstrap condition&#39;&#39;, namely, that they should be proportional to the gluon wave function. The gluon wave function found from this assumption is used to write the full bootstra

S. Y. Choi, J. Kalinowski

The event characteristics of chargino pair production at e+e- collisions are explored to determine gaugino-higgsino mixing angles. We demonstrate that by measuring total cross sections and left-right asymmetries with polarized beams or angular correlations among chargino decay products the fundamental SUSY parameters M_2, μand tan(beta) can be uniquely deter

F. M. Steffens

We work with two general factorization schemes in order to explore the consequences of imposing scheme independence on $g_1^p (x, Q^2)$. We see that although the light quark sector is indifferent to the choice of a particular scheme, the extension of the calculations to the heavy quark sector indicates that a scheme like the $\bar{MS}$ is preferable.

M. Vanderhaeghen, P. A. M. Guichon, M. Guidal

We give predictions for the leading order amplitudes for deeply virtual Compton scattering and hard meson electroproduction reactions at large Q^2 in the valence region in terms of skewed quark distributions. We give first estimates for the power corrections to these leading order amplitudes. In particular, we outline examples of experimental opportunities t

Sh. Matsumoto, M. Yoshimura

A convenient form of kinetic equation is derived for pair annihilation of heavy stable particles relevant to the dark matter problem in cosmology. The kinetic equation thus derived extends the on-shell Boltzmann equation in a most straightforward way, including the off-shell effect. A detailed balance equation for the equilibrium abundance is further analyze

Y. F. Gu, S. F. Tuan

Recent experimental results on the decays of charmonium, together with related physics issues, are reviewed. Some future prospects are described.

Stefano Forte

We review how experimental data collected at the HERA lepton-hadron collider have improved our theoretical and phenomenological understanding of the standard model, and specifically of its QCD sector.

Edward W. Kolb

There is very strong circumstantial evidence that there was an inflationary epoch very early in the history of the universe. In this lecture I will describe how we might be able to piece together some understanding of the dynamics during and immediately after the inflationary epoch.

Thomas G. Rizzo

We review the capability of colliders to detect the virtual exchange of Kaluza-Klein towers of gravitons within the low scale quantum gravity scenario of Arkani-Hamed, Dimopoulos and Dvali.

E. M. Lipmanov

A neutrino mass dominance quantity is introduced for tagging the neutrino flavor in the phenomenological two-parameter four neutrino mixing matrix with two neutrino mass doublets and thorough maximal neutrino doublet mixing. While there is no hierarchy of the neutrino masses in the neutrino flavor eigenstates of this model, it may rather be a special hierarc

Roland E. Allen

A new theory makes testable predictions: (1) Higgs fields have an unconventional equation of motion. (2) Fermions have a second-order coupling to gauge fields. (3) Fermion propagators are modified at high energy. (4) There are new scalar bosons which are supersymmetric partners of spin 1/2 fermions. (5) Since W-bosons gravitate differently from fermions and

I. L. Bogolubsky, V. K. Mitrjushkin, M. Müller-Preussker, P. Peter

For the Lorentz gauge the influence of Gribov copies on the fermion propagator is investigated in quenched lattice compact QED. In the Coulomb phase zero-momentum modes of the gauge fields are shown to be the main reason for a significant deviation from ordinary perturbation theory.

H. Ma, R. Appel, G. S. Atoyan, B. Bassalleck

More than 400 $K^{+}\toπ^{+}μ^+μ^-$ events were observed in a rare $K^+$ decay experiment at the AGS. Normalized to the $K^{+}\toπ^{+}π^+π^-$ decay, the branching ratio is determined to be $(9.22 \pm 0.60 (stat) \pm 0.49 (syst))\times 10^{-8}$. This branching ratio and the $μμ$ mass spectrum is in very good agreement with the measurement of the $K^{+}\toπ^{+

S. Anderson, CLEO Collaboration

We report on a study of the invariant mass spectrum of the hadronic system in the decay tau- -> pi- pi0 nu_tau. This study was performed with data obtained with the CLEO II detector operating at the CESR e+ e- collider. We present fits to phenomenological models in which resonance parameters associated with the rho(770) and rho(1450) mesons are determined. T

A. A. Coley

Dynamical systems theory is especially well-suited for determining the possible asymptotic states (at both early and late times) of cosmological models, particularly when the governing equations are a finite system of autonomous ordinary differential equations. We begin with a brief review of dynamical systems theory. We then discuss cosmological models as d

B. V. Ivanov

An exact twisting type N vacuum solution is found. It has regular gauge and curvature invariants and decays to flat spacetime for big retarded times.

Arbab I. Arbab

We have studied a cosmological model with a cosmological term of the form $Λ=3α\fr{\dot R^2}{R^2}+\bt\fr{\ddot R}{R}+\fr{3γ}{R^2} α, \ \bt γ$ are constants. The scale factor (R) is found to vary linearly with time for both radiation and matter dominated epochs. The cosmological constant is found to decrease as $t^{-2}$ and the rate of particle creation is sm

S. Y. Wang

Many applications want to use TCP congestion control to regulate the transmission rate of a data packet stream. A natural way to achieve this goal is to transport the data packet stream on a TCP connection. However, because TCP implements both congestion and error control, transporting a data packet stream directly using a TCP connection forces the data pack

Jeff Erickson

We propose a hybrid image-space/object-space solution to the classical hidden surface removal problem: Given n disjoint triangles in Real^3 and p sample points (``pixels&#39;&#39;) in the xy-plane, determine the first triangle directly behind each pixel. Our algorithm constructs the sampled visibility map of the triangles with respect to the pixels, which is

Juergen Dix, Mirco Nanni, VS Subrahmanian

Agents are small programs that autonomously take actions based on changes in their environment or ``state.&#39;&#39; Over the last few years, there have been an increasing number of efforts to build agents that can interact and/or collaborate with other agents. In one of these efforts, Eiter, Subrahmanian amd Pick (AIJ, 108(1-2), pages 179-255) have shown ho

I. Vekhter, L. N. Bulaevskii, A. E. Koshelev, M. P. Maley

We calculate the dependence of the interlayer quasiparticle conductivity, $σ_q$, in a Josephson coupled d-wave superconductor on the magnetic field B||c and the temperature T. We consider a clean superconductor with resonant impurity scattering and a dominant coherent interlayer tunneling. When pancake vortices in adjacent layers are weakly correlated at low

V. M. Kendon, M. E. Cates, J-C. Desplat

The persistence exponent, theta, is defined by N_F sim t^theta, where t is the time since the start of the coarsening process and the &#34;no-flip fraction&#34;, N_F, is the number of points that have not seen a change of &#34;color&#34; since t=0. Here we investigate numerically the persistence exponent for a binary fluid system where the coarsening is domi

Welles A. M. Morgado, Gilson Carneiro

A numerical method to calculate equilibrium vortex-line configurations in bulk anisotropic type-II superconductors, at zero temperature, placed in an external magnetic field is introduced and applied to two physical problems. The method is designed to search for the minimum of the Gibbs free-energy in the London approximation and assumes only that the vortex

H. Kroemmer, A. Erbe, A. Tilke, S. Manus

We present measurements on nanomechanical resonators machined from Silicon-on-Insulator substrates. The resonators are designed as freely suspended Au/Si beams of lengths on the order of 1 - 4 um and a thickness of 200 nm. The beams are driven into nonlinear response by an applied modulation at radio frequencies and a magnetic field in plane. The strong hyst