June 1999 arXiv papers — page 3

Francois Schweizer

Star formation in starbursts appears to be biased toward compact clusters, with up to 20% of all stars formed in them. Observations with HST show that many of these clusters have luminosities (-9 > Mv > -16), UBVI colors, and half-light radii (R_eff = ~3 pc) consistent with their being young globular clusters. Although we know little about the long-term stab

Shoko Sakai, Laura Ferrarese, Robert C. Kennicutt, John A. Graham

The distance to NGC 3319 has been determined from Cepheid variable stars as part of the Hubble Space Telescope Key Project on the Extragalactic Distance Scale. Thirteen and four epochs of observations, using filters F555W (V) and F814W (I) respectively, were made with the Wide Field Planetary Camera 2. Thirty-three Cepheid variables between periods of 8 and

Charles F. Prosser, Robert C. Kennicutt,, Fabio Bresolin, Abhijit Saha

We report on the detection of Cepheids and the first distance measurement to the spiral galaxy NGC 1326-A, a member of the Fornax cluster of galaxies. We have employed data obtained with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope. Over a 49 day interval, a total of twelve V-band (F555W) and eight I-band (F814W) epochs of observ

J. A. Eilek

It is now well established that the plasma in galaxy clusters is magnetized. In some cases, at least, the field is strong enough to be dynamically important. Perhaps this is the time to move past simple detection experiments, and to work towards a general understanding of the strength, structure and maintenance of the cluster field.

Shoko Sakai, Barry Madore

We present color-magnitude diagrams and luminosity functions of stars in two halo regions of the irregular galaxy in M82, based on F555W and F814W photometry taken with the Hubble Space Telescope and Wide Field Planetary Camera 2. The I-band luminosity function shows a sudden jump at I~23.95 mag, which is identified as the tip of the red giant branch (TRGB).

E. Antonello, L. Mantegazza, D. Fugazza, M. Bossi

The first results are presented of a four-year program dedicated to the CCD observations of Cepheids in the nearby galaxy IC 1613. Since the program was carried out with a relatively small telescope, the Dutch 0.9 m at ESO-La Silla, the observations were performed without filter (white light), or Wh-band; the advantage of this technique is that the photon st

F. K. Sutaria, A. Ray, J. A. Sheikh, P. Ring

The spectroscopy of electron capture neutrinos emitted from nearby pre-supernova collapsing stars before the neutrino trapping sets in, can yield useful information on the physical conditions and on the nuclear composition of the core. The neutrino spectrum depends on the thermodynamic conditions of the core, the nuclear abundances, the lepton fractions and

Ivaylo Zlatev, Paul J. Steinhardt

Recently, we introduced the notion of "tracker fields," a form of quintessence which has an attractor-like solution. Using this concept, we showed how to construct models in which the ratio of quintessence to matter densities today is independent of initial conditions. Here we apply the same idea to the standard cold dark matter component in cases wh

R. R. Gal, S. C. Odewahn, S. G. Djorgovski, R. Brunner

We report on the creation of an unbiased catalog of galaxy clusters from the galaxy catalogs derived from the digitized POSS-II (DPOSS). Utilizing the g-r color information, we show that it is possible to estimate redshifts for galaxy clusters at z<0.4 with an rms accuracy of 0.01.

Donald F. Figer, Mark Morris, T. R. Geballe, R. Michael Rich

We present new NICMOS/HST infrared images and CGS4/UKIRT Br-alpha (4.05 um) spectroscopy of the Pistol Star and its associated nebula, finding strong evidence to support the hypothesis that the Pistol Nebula was ejected from the Pistol Star. The Pa-alpha NICMOS image shows that the nebula completely surrounds the Pistol Star, although the line intensity is m

W. R. Hix, F. -K. Thielemann

This review concentrates on the two principle methods used to evolve nuclear abundances within astrophysical simulations, evolution via rate equations and via equilibria. Because in general the rate equations in nucleosynthetic applications form an extraordinarily stiff system, implicit methods have proven mandatory, leading to the need to solve moderately s

F. Combes

The interstellar medium is structured as a hierachy of gas clouds, that looks self-similar over 6 orders of magnitude in scales and 9 in masses. This is one of the more extended fractal in the Universe. At even larger scales, the ensemble of galaxies looks also self-similar over a certain ranges of scales, but more limited, may be over 3-4 orders of magnitud

Jacco Vink, Jelle S. Kaastra, Johan A. M. Bleeker, Hans Bloemen

We present an analysis of the BeppoSAX high X-ray energy spectrum of the supernova remnant Cassiopeia A with an observation time of 83 ks. We measure a flux upper limit of 4.1E-5 ph/cm^2/s (99.7% confidence) of the nuclear decay lines of Ti-44 at 68 keV and 78 keV that is lower and inconsistent with the flux of an accompanying line at 1157 keV measured by CG

Jens Schmalzing, Stefan Gottloeber, Anatoly A. Klypin, Andrey V. Kravtsov

We use a high-resolution dissipationless simulation to study the evolution of the dark matter and halo distributions in a spatially flat cosmological model dominated by a cosmological constant $Λ$ and cold dark matter ($Λ$CDM). In order to quantify the evolution of structure, we calculate the Minkowski functionals of the halos and the dark matter component a

T. Bloecker, Y. Balega, K. -H. Hofmann, J. Lichtenthaeler

The hypergiant IRC+10420 is a unique object for the study of stellar evolution since it is the only object that is believed to be witnessed in its rapid transition from the red supergiant stage to the Wolf-Rayet phase. Its effective temperature has increased by 1000-2000K within only 20yr. We present the first speckle observations of IRC+10420 with 73mas res

Andrew Gould

I show that by observing microlensing events both astrometrically and photometrically, the Space Interferometry Mission (SIM) can measure the mass function of stellar remnants in the Galactic bulge including white dwarfs, neutron stars, and black holes. Neutron stars and black holes can be identified individually, while white dwarfs are detected statisticall

Gabriele Ghisellini, Davide Lazzati

The recently detected linear polarization in the optical lightcurve of GRB 990510 renewed the interest on how polarization can be produced in gamma-ray burst fireballs. Here we present a model based on the assumption that we are seeing a collimated fireball, observed slightly off-axis. This introduces some degree of anisotropy, and makes it possible to obser

Michael L. Balogh, S. L. Morris, H. K. C. Yee, R. G. Carlberg

(abridged) We measure spectral indices for 1823 galaxies in the CNOC1 sample of fifteen X-ray luminous clusters at 0.18<z<0.55, to investigate the mechanisms responsible for differential evolution between the galaxy cluster and field environments. The radial trends of D4000, Hdelta and [OII] are all consistent with an age sequence, in the sense that the last

Chang Won Lee, Philip C. Myers, Mario Tafalla

In this paper, we present the first results of a survey of 220 starless cores selected primarily by their optical obscuration (Lee & Myers 1999) and observed in CS (2-1), N$_2$H$^+$ (1-0), and C$^{18}$O (1-0) using the NEROC Haystack 37-m telescope, to quantify the incidence of infall motions toward starless cores and find infall candidates for further study

Andrew Cumming, Geoffrey W. Marcy, R. Paul Butler

We analyse 11 years of precise radial velocities for 76 solar type stars from the Lick survey. Eight stars in this sample have previously reported planetary-mass companions, all with mass (m sin i) less than 8 Jupiter masses (MJ). For the stars without a detected companion, we place upper limits on possible companion mass. For most stars, we can exclude comp

Patrick Cote

HIRES on the Keck I telescope has been used to measure the first radial velocities for stars belonging to eleven, heavily-reddened globular clusters in the direction of the inner Galaxy. The question of kinematic substructuring among the Galactic globular cluster system is investigated using an updated catalog of globular cluster distances, metallicities and

J. Bolte, B. Müller, A. Schäfer

We investigate the relationship between the Lyapunov exponents of periodic trajectories, the average and fluctuations of Lyapunov exponents of ergodic trajectories, and the ergodic autocorrelation time for the two-dimensional hyperbola billiard. We then study the fluctuation properties of the ergodic Lyapunov spectrum of classical SU(2) gauge theory on a lat

John B. Etnyre

We classify positive transversal torus knots in tight contact structures up to transversal isotopy.

Zurab Kakushadze

In this note we discuss dynamical mechanisms for brane stabilization in the brane world context. In particular, we consider supersymmetry preserving brane stabilization, and also brane stabilization accompanied by supersymmetry breaking. These mechanisms are realized in some four dimensional N=1 supersymmetric orientifold models. For illustrative purposes we

Igor R. Klebanov

We consider duality between type 0B string theory on $AdS_5\times S^5$ and the planar CFT on $N$ electric D3-branes coincident with $N$ magnetic D3-branes. It has been argued that this theory is stable up to a critical value of the `t Hooft coupling but is unstable beyond that point. We suggest that from the gauge theory point of view the development of inst

Denise R. Goncalves, Amancio C. S. Friaca

A possible discrepancy found in the determination of mass from gravitational lensing data, and from X-rays observations, has been largely discussed in the latest years (for instance, Miralda-Escude & Babul (1995)). Another important discrepancy related to these data is that the dark matter is more centrally condensed than the X-ray-emitting gas, and also wit

R. R. Metsaev

Light-cone form of field dynamics in anti-de Sitter space-time is developed. Using field theoretic and group theoretic approaches the light-cone representation for generators of anti-de Sitter algebra acting as differential operators on bulk fields is found. We also present light-cone reformulation of the boundary conformal field theory representations. Maki

Patrick Dorey, Roberto Tateo

The vacuum expectation values of the so-called Q-operators of certain integrable quantum field theories have recently been identified with spectral determinants of particular Schrodinger operators. In this paper we extend the correspondence to the T-operators, finding that their vacuum expectation values also have an interpretation as spectral determinants.

M. Zoccali, S. Cassisi, J. A. Frogel, A. Gould

We present a luminosity function (LF) for lower main sequence stars in the Galactic bulge near (l,b)=(0,-6) to J=24, corresponding to M_J~9.3. This LF is derived from HST + NICMOS observations with the F110W and F160W filters. The main sequence locus in the infrared shows a strong change in slope at J~20.5 (M_J~5.75) which is well fit by new low mass models

D. Arnaudon, J. Avan, L. Frappat, E. Ragoucy

A self-contained description of algebraic structures, obtained by combinations of various limit procedures applied to vertex and face sl(2) elliptic quantum affine algebras, is given. New double Yangians structures of dynamical type are in particular defined. Connections between these structures are established. A number of them take the form of twist-like a

James M. Cline, Christophe Grojean, Geraldine Servant

It has recently been pointed out that global solutions of Einstein&#39;s equations for a 3-brane universe embedded in 4 spatial dimensions give rise to a Friedmann equation of the form H ~ rho on the brane, instead of the usual H ~ (rho)^{1/2}, which is inconsistent with cosmological observations. We remedy this problem by adding cosmological constants to th

Song Gao, Charles Gale, Christoph Ernst, Horst Stöcker

The modification of the width of the rho meson due to in-medium decays and collisions is evaluated. In high temperature and/or high density hadronic matter, the collision width is much larger than the one-loop decay width. The large width of the $ρ$ meson in matter seems to be consistent with some current interpretations of the $e^+ e^-$ mass spectra measure

Shin&#39;ichi Nojiri, Sergei D. Odintsov

We discuss the non-constant dilaton deformed ${\rm AdS}_5\times{\rm S}_5$ solutions of IIB supergravity where AdS sector is described by black hole. The investigation of running gauge coupling (exponent of dilaton) of non-SUSY gauge theory at finite temperature is presented for different regimes (high or low T, large radius expansion). Running gauge coupling

J. Teschner

Precise descriptions are given for the operator product expansion of generic primary fields as well as the factorization of four point functions as sum over intermediate states. The conjecture underlying the recent derivation of the space-time current algebra for string theory on $ADS_3$ by Kutasov and Seiberg is thereby verified. The roles of microscopic an

Tommy Ohlsson, Hakan Snellman

We discuss symmetry breaking in the weak magnetism form factors for the semileptonic octet baryon decays. In the chiral quark model, the symmetry breaking can be accounted for in the masses and the quark spin polarizations can take on more general values due to Goldstone boson depolarization. Here we clarify some features of the chiral quark model prediction

J. -P. Martikainen, K. -A. Suominen

We investigate the validity of the Landau-Zener model in describing the output coupling of Bose condensates from magnetic traps by a chirped radiofrequency field. The predictions of the model are compared with the numerical solutions of the Gross-Pitaevskii equation. We find a dependence on the chirp direction, and also quantify the role of gravitation.

N. N. Achasov, A. A. Kozhevnikov

It is shown that the phase of phi-omega interference in the reaction e^+e^- -->pi^+ pi^- pi^0 at energies close to the phi(1020) peak can be calculated in a way that is practically independent of the model of phi-omega mixing. The magnitude of the presently measured interference phase, still of poor accuracy, is in agreement with the predictions based on ext

Michael J. W. Hall, Martina S. Reineker, Wolfgang P. Schleich

Quantum carpets are generic spacetime patterns formed in the probability distributions P(x,t) of one-dimensional quantum particles, first discovered in 1995. For the case of an infinite square well potential, these patterns are shown to have a detailed quantitative explanation in terms of a travelling-wave decomposition of P(x,t). Each wave directly yields t

P. Di Vecchia, M. Frau, A. Lerda, A. Liccardo

We use the boundary state formalism to provide the full conformal description of (F,Dp) bound states. These are BPS configurations that arise from a superposition of a fundamental string and a Dp brane, and are charged under both the NS-NS antisymmetric tensor and the (p+1)-form R-R potential. We construct the boundary state for these bound states by switchi

B. Kleihaus, D. H. Tchrakian, F. Zimmerschied

We construct the finite energy path between topologically distinct vacua of a 4 dimensional SO(4) Higgs model which is known to support an instanton, and show that there is a sphaleron with Chern-Simons number N_CS=1/2 at the top of the energy barrier. This is carried out using the original geometric loop construction of Manton.

J. Erickson, G. W. Semenoff, K. Zarembo

Correlators of Wilson loop operators with O_4=Tr(F_{μν}^2+...) are computed in N=4 super-Yang-Mills theory using the AdS/CFT correspondence. The results are compared with the leading order perturbative computations. As a consequence of conformal invariance, these correlators have identical forms in the weak and strong coupling limits for circular loops. They

Heng Fan, Miki Wadati, Rui-hong Yue

We study the generalized supersymmetric t-J model with Kondo impurities in the boundaries. We first construct the higher spin operator K-matrix for the XXZ Heisenberg chain. Setting the boundary parameter to be a special value, we find a higher spin reflecting K-matrix for the supersymmetric t-J model. By using the Quantum Inverse Scattering Method, we obtai

Y. G. Ganjali, M. Ghebleh, H. Hajiabolhassan, M. Mirzazadeh

A graph is called to be uniquely list colorable, if it admits a list assignment which induces a unique list coloring. We study uniquely list colorable graphs with a restriction on the number of colors used. In this way we generalize a theorem which characterizes uniquely 2-list colorable graphs. We introduce the uniquely list chromatic number of a graph and

Andrew W. Blain

It is difficult to identify the distant galaxies selected in existing submillimetre-wave surveys, because their positions are known at best to only several arcseconds. Centimetre-wave VLA observations are required in order to determine positions to subarcsecond accuracy, and so to allow reliable optical identifications to be made. Carilli & Yun pointed out t

The OPAL Collaboration, G. Abbiendi

The total hadronic cross-section sigma_gg(W) for the interaction of real photons, gg->hadrons, is measured for gg centre-of-mass energies 10<W<110 GeV. The cross-section is extracted from a measurement of the process e+e- -> e+e-g*g* -> e+e- hardrons, using a luminosity function for the photon flux together with form factors for extrapolating to real photons

Valery P. Gusynin, Vadim M. Loktev, Rachel M. Quick, Sergei G. Sharapov

The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction has been studied. Analytic expressions for the fermion Green function, its spectral density and the density of states are derived. The resultant single-particle Green function clearly demon

Shigenori Seki

The Type 0 string theory is considered as a dual model of a non-supersymmetric gauge theory. A background geometry with N electric D3-branes is calculated in UV/IR regions. In this paper, we study a D5-brane around N D3-branes from the D5-brane world volume action as in the Type IIB case, and we obtain some baryon configurations at UV/IR regions.

Hiroshi Imamura, Nobuhiko Kobayashi, Saburo Takahashi, Sadamichi Maekawa

We theoretically study the electron transport through a magnetic point contact (PC) with special attention to the effect of an atomic scale domain wall (DW). The spin precession of a conduction electron is forbidden in such an atomic scale DW and the sequence of quantized conductances depends on the relative orientation of magnetizations between left and rig

A. P. Potylitsyn, P. V. Karataev, G. A. Naumenko

A simple model for calculating the diffraction radiation characteristics from an ultrarelativistic charged particle moving close to a tilted ideally conducting strip is developed. Resonant diffraction radiation (RDR) is treated as a superposition of the radiation fields for periodically spaced strips. The RDR characteristics have been calculated as a functio

Sasanka Ghosh, Sudipta Nandy

Existence of a new class of soliton solutions is shown for higher order nonlinear Schrodinger equation, describing thrid order dispersion, Kerr effect and stimulated Raman scattering. These new solutions have been obtaiened by invoking a group of nonlinear transformations acting on localised stable solutions. Stability of these solutions has been studied for

Tim Hoffmann

The equivalence of the discrete isotropic Heisenberg magnet (IHM) model and the discrete nonlinear Schrödinger equation (NLSE) given by Ablowitz and Ladik is shown. This is used to derive the equivalence of their discretization with the one by Izergin and Korepin. Moreover a doubly discrete IHM is presented that is equivalent to Ablowitz&#39; and Ladiks doub

M. Adler, P. J. Forrester, T. Nagao, P. van Moerbeke

Skew orthogonal polynomials arise in the calculation of the $n$-point distribution function for the eigenvalues of ensembles of random matrices with orthogonal or symplectic symmetry. In particular, the distribution functions are completely determined by a certain sum involving the skew orthogonal polynomials. In the cases that the eigenvalue probability den

Richard Cleve

We give a basic overview of computational complexity, query complexity, and communication complexity, with quantum information incorporated into each of these scenarios. The aim is to provide simple but clear definitions, and to highlight the interplay between the three scenarios and currently-known quantum algorithms.

V. N. Gorbachev, A. I. Trubilko

Teleportation of an EPR pair using triplet in state of the Horne-Greenberger-Zeilinger form to two receivers is considered. It needs a three-particle basis for joint measurement. By contrast the one qubit teleportation the required basis is not maximally entangled. It consists of the states corresponding to the maximally entanglement of two particles only. U

G. P. Berman, A. R. Bishop, G. D. Doolen, G. V. Lopez

We study numerically the influence of non-resonant effects on the dynamics of a single $π$-pulse quantum CONTROL-NOT (CN) gate in a macroscopic ensemble of fo ur-spin molecules at room temperature. The four nuclear spins in each molecule r epresent a four-qubit register. The qubits are ``labeled&#39;&#39; by the characteristic frequencies, $ω_k$, ($k=0$ to 3

Domenico Giulini

The process of dynamical decoherence may cause apparent superselection rules, which are sometimes called `environmentally induced&#39; or `soft&#39;. A natural question is whether such dynamical processes are eventually also responsible for at least some of the superselection rules which are usually presented as fundamentally rooted in the kinematical struct

S. N. Molotkov, S. S. Nazin

The scheme for measurement of the state of a single spin (or a few spin system) based on the single-electron turnstile and injection of spin polarized electrons from magnetic metal contacts is proposed. Applications to the recent proposal concerning the spin gates based on a silicon matrix (B.Kane, Nature, {\bf 393}, 133 (1998)) are discussed.

N. J. Cerf, N. Gisin, S. Massar

Classical teleportation is defined as a scenario where the sender is given the classical description of an arbitrary quantum state while the receiver simulates any measurement on it. This scenario is shown to be achievable by transmitting only a few classical bits if the sender and receiver initially share local hidden variables. Specifically, a communicatio

V. A. Skrebnev, M. N. Ovchinnikov

Metrical separability of the spin systems energetic surfaces is shown. The irreversibility of the spin system evolution is considered as the consequence of random quantum jumps on energy surfaces.

Anthony J. Baltz

The time-dependent Dirac equation can be solved exactly for ionization induced by ultrarelativistic heavy ion collisions. Ionization calculations are carried out in such a framework for a number of representative ion-ion pairs. For each ion-ion pair, the computed cross section consists of two terms, a constant energy independent term and a term whose coeffic

D. E. Kahana, S. H. Kahana

The H dibaryon, a single, triply magic bag containing two up, two down and two strange quarks, has long been sought after in a variety of experiments. Its creation has been attempted in $K^-$, proton and most recently in relativistic heavy ion induced reactions. We concentrate on the latter, but our conclusions are more generally applicable. The two baryons

K. A. Bugaev, M. I. Gorenstein, W. Greiner

Freeze-out of particles in relativistic hydrodynamics is considered across a 3-dimensional space-time hypersurface. The conservation laws for time-like parts of the freeze-out hypersurface require different values of temperature, baryonic chemical potential and flow velocity in the fluid and in the final particle spectra. We analyze this freeze-out discontin

D. R. Phillips, S. J. Wallace, N. K. Devine

Using a three-dimensional formalism that includes relativistic kinematics, the effects of negative-energy states, approximate boosts of the two-body system, and current conservation we calculate the electromagnetic form factors of the deuteron up to $Q^2=6$ GeV$^2$. This is done both in impulse approximation and with a $ρπγ$ meson-exchange current included.

M. Effenberger, U. Mosel

We investigate the observable effects of off-shell propagation of nucleons in heavy-ion collisions at SIS energies. Within a semi-classical BUU transport model we find a strong enhancement of subthreshold particle production when off-shell nucleons are propagated.

B. I. S. van der Ventel, G. C. Hillhouse, P. R. De Kock, S. J. Wallace

For the calculation of polarization transfer observables for quasielastic scattering of protons on nuclei, a formalism in the context of the Relativistic Plane Wave Impulse Approximation is developed, in which the interaction matrix is expanded in terms of a complete set of 44 independent invariant amplitudes. A boson-exchange model is used to predict the 39

Richard M. Aron, Juan P. Bes

A classical theorem due to G.D. Birkhoff states that there exists an entire function whose translates approximate any given entire function, as accurately as desired, over any ball of the complex plane. We show this result may be generalized to the space of entire functions of compact bounded type defined on a Banach space with separable dual.

Andrew J. Sommese, Jan Verschelde

Many applications modeled by polynomial systems have positive dimensional solution components (e.g., the path synthesis problems for four-bar mechanisms) that are challenging to compute numerically by homotopy continuation methods. A procedure of A. Sommese and C. Wampler consists in slicing the components with linear subspaces in general position to obtain

Juan P. Bes

We show that every hypercyclic operator on a real locally convex space admits a dense, invariant linear manifold of hypercyclic vectors.

Timo Seppalainen

This paper summarizes results and some open problems about the large-scale and long-time behavior of asymmetric, disordered exclusion and zero-range processes. These processes have randomly chosen jump rates at the sites of the underlying lattice. The interesting feature is that for suitably distributed random rates there is a phase transition where the proc

Timo Seppalainen

We prove a hydrodynamic limit for ballistic deposition on a multidimensional lattice. In this growth model particles rain down at random and stick to the growing cluster at the first point of contact. The theorem is that if the initial random interface converges to a deterministic macroscopic function, then at later times the height of the scaled interface c

Timo Seppalainen

We prove a weak law of large numbers for a tagged particle in a totally asymmetric exclusion process on the one-dimensional lattice. The particles are allowed to take long jumps but not pass each other. The object of the paper is to illustrate a special technique for proving such theorems. The method uses a coupling that mimics the Hopf-Lax formula from the

V. Gritsenko

The elliptic genus (EG) of a compact complex manifold was introduced as a holomorphic Euler characteristic of some formal power series with vector bundle coefficients. EG is an automorphic form in two variables only if the manifold is a Calabi--Yau manifold. In physics such a function appears as the partition function of N=2 superconformal field theories. In

V. Gritsenko

In the paper we study two types of relations: a one is between the elliptic genus of Calabi-Yau manifolds and Jacobi modular forms, another one is between the second quantized elliptic genus, Siegel modular forms and Lorentzian Kac-Moody Lie algebras. We also determine the structure of the graded ring of the weak Jacobi forms with integral Fourier coefficien

Arupkumar Pal

A semiregular operator on a Hilbert C^*-module, or equivalently, on the C^*-algebra of `compact&#39; operators on it, is a closable densely defined operator whose adjoint is also densely defined. It is shown that for operators on extensions of compacts by unital or abelian C^*-algebras, semiregularity leads to regularity. Two examples coming from quantum gro

I. Bars, C. Deliduman, D. Minic

We generalize the ideas and formalism of Two-Time Physics from particle dynamics to some specific examples of string and p-brane (p >= 1) dynamics. The two-time string or p-brane action can be gauge fixed to produce various one-time string or p-brane actions that are dual to each other under gauge transformations. We discuss the particular gauges that corres

M. Cvetic, H. Lu, C. N. Pope

We obtain the complete non-linear Kaluza-Klein ansatz for the reduction of the bosonic sector of massive type IIA supergravity to the Romans F(4) gauged supergravity in six dimensions. The latter arises as a consistent warped S^4 reduction.

H. J. de Vega, A. L. Larsen, N. Sanchez

Non-singular two and three dimensional string cosmologies are constructed using the exact conformal field theories corresponding to SO(2,1)/SO(1,1) and SO(2,2)/SO(2,1). All semi-classical curvature singularities are canceled in the exact theories for both of these cosets, but some new quantum curvature singularities emerge. However, considering different pat

K. J. Barnes

Supersymmetric $σ$-models obtained by constraining linear supersymmetric field theories are ill defined. Well defined subsectors parametrising Kahler manifolds exist but are not believed to arise directly from constrained linear ones. A counterexample is offered using improved understanding of membranes in superstring theories leading to crucial central term

M A Grigoriev

I point out an unexpected relation between the BV (Batalin-Vilkovisky) and the BFV (Batalin-Fradkin-Vilkovisky) formulations of the same pure gauge (topological) theory. The nonminimal sector in the BV formulation of the topological theory allows one to construct the Poisson bracket and the BRST charge on some Lagrangian submanifold of the BV configuration s

G. Van Hooydonk

Absolute scaling electrical with gravitational forces has remained unsuccessful until today. Using recent results on scaling spectroscopic constants, we now scale the internal electrical potential of a two particle system by its gravitational potential at the surface of the earth. This relative scaling is based upon classical equilibrium conditions. Compacti

Leonard Gamberg, George R. Kalbfleisch, Kimball A. Milton

Recently, there has been renewed interest in the search for low-mass magnetic monopoles. At the University of Oklahoma we are performing an experiment (Fermilab E882) using material from the old D0 and CDF detectors to set limits on the existence of Dirac monopoles of masses of the order of 500 GeV. To set such limits, estimates must be made of the productio

Francesco Vissani

The lower and upper bounds on the neutrinoless double beta (0nu-2beta) decay rate are obtained, as functions of the parameters of neutrino oscillations and of the lightest neutrino mass. The constraints on these parameters from the search for the 0nu-2beta transition, as well as from the interpretation of solar and atmospheric neutrino data in terms of oscil

F. Carvalho, F. O. Durães, F. S. Navarra, M. Nielsen

We have applied the Meson Cloud Model to calculate inclusive momentum spectra of pions and kaons produced in high energy proton-proton and proton-nucleus collisions. For the first time these data are used to constrain the cloud cut-off parameters. We show that it is possible to obtain a reasonable description of data, especially the large $x_F$ ($x_F \geq 0.

J. C. Romao

We discuss gauge and Yukawa unification in the context of a supersymmetric model with bilinear R-parity violation. We show that this model allows $b-τ$ Yukawa unification for any value of $\tanβ$ while satisfying perturbativity of the couplings. We also find the $t-b-τ$ Yukawa unification easier to achieve than in the MSSM, occurring in a wider high $\tanβ$

Hiroaki Kouno, Akira Hasegawa, Masahiro Nakano, Kunito Tuchitani

We study nonlinear effects in the QED ladder Schwinger-Dyson(SD) equation. Without further approximations, we show that all nonlinear effects in the ladder SD equation can be included in the effective couplings and how a linear approximation works well. The analyses is generalized in the case of the improved ladder calculation with the Higashijima-Miransky a

M. Diehl

I review various theory issues in diffraction that have been presented and discussed in the working group on diffractive interactions, and a few points concerning the comparison of theory with data.

G. Burgio, R. De Pietri, H. A. Morales-Tecotl, L. F. Urrutia

Non-linear Fourier analysis on compact groups is used to construct an orthonormal basis of the physical (gauge invariant) Hilbert space of Hamiltonian lattice gauge theories. In particular, the matrix elements of the Hamiltonian operator involved are explicitly computed. Finally, some applications and possible developments of the formalism are discussed.

S. Güsken

The calculation of physical quantities by lattice QCD simulations requires in some important cases the determination of the inverse of a very large matrix. In this article we describe how stochastic estimator methods can be applied to this problem, and how such techniques can be efficiently implemented on parallel computers.

S. Güsken

Flavor singlet combinations of quark operators ${\cal{O}}_S^Γ = \bar{u}Γu + \bar{d}Γd + \bar{s}Γs$ contribute to many important physical observables in the low energy region of QCD. Experimentally one finds the values of some of these observables to be in sharp contrast to the naive (perturbative) theoretical expectations. This indicates that non perturbativ

Claudia Glasman

Measurements of jet, prompt photon, high-pT hadron and heavy quark production in photon-induced processes provide tests of QCD and are sensitive to the photon parton densities. A review of the latest experimental results in photon-photon and photon-proton interactions is presented. Next-to-leading-order QCD calculations for these measurements are discussed.

Jayashree Balakrishna

The study of the properties and dynamics of self-gravitating bosonic objects in Einstein gravity was conducted. We studied self-coupled boson stars and determined the quasinormal mode (QNM) frequencies of stable boson stars in spherical symmetry. The study was carried out in the standard Einstein theory of General Relativity and in Brans-Dicke theory. We als

D. Paun, M. Chechik

For over a decade, researchers in formal methods tried to create formalisms that permit natural specification of systems and allow mathematical reasoning about their correctness. The availability of fully-automated reasoning tools enables more non-specialists to use formal methods effectively --- their responsibility reduces to just specifying the model and

M. Chechik

This paper gives an overview of SCR3 -- a toolset designed to increase the usability of formal methods for software development. Formal requirements are specified in SCR3 in an easy to use and review format, and then used in checking requirements for correctness and in verifying consistency between annotated code and requirements. In this paper we discuss mo

Jeffrey L. Billeter, Alexander M. Smondyrev, George B. Loriot, Robert A. Pelcovits

Phase-ordering dynamics in nematic liquid crystals has been the subject of much active investigation in recent years in theory, experiments and simulations. With a rapid quench from the isotropic to nematic phase a large number of topological defects are formed and dominate the subsequent equilibration process. We present here the results of a molecular dyna

Ingve Simonsen, Remi Lazzari, Jacques Jupille, Stephane Roux

The present work reports a general method for the calculation of t he polarizability of a truncated sphere on a substrate. A multipole ex pansion is used, where the multipoles are not necessarily localized in the center of the sphere but can freely move on the revolution axis. From the weak formulation of the boundary conditions, an infinite set of linear eq

Youichi Yanase, Kosaku Yamada

In this paper we study the effects of the strong coupling superconductivity on the normal state electronic structure. We point out that the pseudogap phenomena in High-T_c cuprates are naturally explained as a precursor of the strong coupling superconductivity. We expand the reciprocal of the T-matrix with respect to the momentum and the frequency, and we di

A. P. Mehta, C. Reichhardt, C. J. Olson, Franco Nori

River basins as diverse as the Nile, the Amazon, and the Mississippi satisfy certain topological invariants known as Horton&#39;s laws. Do these macroscopic (up to 10^3 km) laws extend to the micron scale? Through realistic simulations, we analyze the morphology and statistical properties of networks of vortex flow in flux-gradient-driven superconductors. We

Y. N. Skryabin, A. V. Chukin

Taking into account the long-ranged spin interactions due to weak localization effects in disordered itinerant ferromagnets the scattering of both electrons and neutrons on critical spin fluctuations near quantum phase transition is considered. It is shown that for the case of low electron density, when k_F ξ\ll 1, where k_F is the Fermi momentum and ξis the

M. V. Voinova, M. Jonson, B. Kasemo

We analyze theoretically the effect of friction on quartz crystal microbalance (QCM) measurements that probe soft (viscoelastic) films and biomolecular layers adsorbed from aqueous solutions. While water provides a natural environment for biomolecules, an interface with unknown rheological properties forms between the adsorbed soft molecular layer and the qu

Gene F. Mazenko

The perturbation theory expansion presented earlier to describe the phase-ordering kinetics in the case of a nonconserved scalar order parameter is generalized to the case of the $n$-vector model. At lowest order in this expansion, as in the scalar case, one obtains the theory due to Ohta, Jasnow and Kawasaki (OJK). The second-order corrections for the noneq