December 2000 arXiv papers — page 7

Toby N Bailey, Liana David

We present a version of the Penrose transform which relates compactly supported cohomology on a complex or CR manifold Z to kernels and cokernels of differential operators on a parameter space X of compact complex submanifolds of Z.

Yasushi Kasahara

We study the algebraic property of the representation of the mapping class group of a closed oriented surface of genus 2 constructed by VFR Jones [Annals of Math. 126 (1987) 335-388]. It arises from the Iwahori-Hecke algebra representations of Artin's braid group of 6 strings, and is defined over integral Laurent polynomials Z[t, t^{-1}]. We substitute t

Michael Atiyah

A cohomological study is made of an equivariant map betwen the configuration space of n points in space and the flag manifold of U(n).

Metod Saniga

The pencil of conics featuring three degenerate conics each of which is a line-pair is briefly inspected in a Galois field of characteristic two. It is shown that if two degenerates are conjugate imaginary line pairs, the third must be a real line pair; this contradicts Campbell's claim (Campbell 1927) that all the three singular conics are conjugate ima

Michael Atiyah

A brief account of K-theory written in honour of Friedrich Hirzebruch

Ivelina Bobtcheva, Frank Quinn

We show that the Reshetikhin-Turaev-Walker invariant of 3-manifolds can be normalized to obtain an invariant of 4-dimensional thickenings of 2-complexes. Moreover when the underlying semisimple tortile category comes from the representations of a quantum group at a primitive prime root of unity, the 0-term in the Ohtsuki expansion of this invariant depends o

Yongbin Ruan

In this article, we study the twisting procedure of orbifold cohomology. We introduce local system and construct twisted orbifold cohomology. Then, we generalize Vafa-Witten's notion of discrete torsion to general orbifold and examine its relation to local system. Finally, some examples are computed.

M. Ertl, W. Kummer, T. Strobl

We provide the geometric actions for most general N=1 supergravity in two spacetime dimensions. Our construction implies an extension to arbitrary N. This provides a supersymmetrization of any generalized dilaton gravity theory or of any theory with an action being an (essentially) arbitrary function of curvature and torsion. Technically we proceed as follow

Steve Corley, Sanjaye Ramgoolam

Projector equivalences used in the definition of the K-theory of operator algebras are shown to lead to generalizations of the solution generating technique for solitons in NC field theories, which has recently been used in the construction of branes from other branes in B-field backgrounds and in the construction of fluxon solutions of gauge theories. The g

John Ellis, N. E. Mavromatos, D. V. Nanopoulos

Modelling space-time foam using a non-critical Liouville-string model for the quantum fluctuations of D branes with recoil, we discuss the issues of momentum and energy conservation in particle propagation and interactions. We argue that momentum should be conserved exactly during propagation and on the average during interactions, but that energy is conserv

Dietmar Klemm

The issue of microstate counting for general black holes in D=5, N=2 supergravity coupled to vector multiplets is discussed from various viewpoints. The statistical entropy is computed for the near-extremal case by using the central charge appearing in the asymptotic symmetry algebra of AdS_2. Furthermore, we show that the considered supergravity theory enjo

J. Fernando Barbero G., Eduardo J. S. Villaseñor

We give in this paper a partial classification of the consistent quadratic gauge actions that can be written in terms of s-form fields. This provides a starting point to study the uniqueness of the Yang-Mills action as a deformation of Maxwell-like theories. We also show that it is impossible to write kinetic 1-form terms that can be consistently added to ot

Jan Naudts, Maciej Kuna

Doplicher, Fredenhagen, and Roberts (1994, 1995) proposed a simple model of a particle in quantum spacetime. We give a new formulation of the model and propose some small changes and additions which improve the physical interpretation. In particular, we show that the internal degrees of freedom e and m of the particle represent external forces acting on the

I. Nandori, J. Polonyi, K. Sailer

The RG flow for the sine-Gordon model is determined by means of the method of Wegner and Houghton in next-to-leading order of the derivative expansion. For small values of the fugacity this agrees with the well-known RG flow of the two-dimensional Coulomb-gas found in the dilute gas approximation and a systematic way of obtaining higher-order corrections to

S. Nagy, K. Sailer

We give a quantum field theoretical treatment of a one dimensional electron system with a fixed chemical potential $μ$. The non-perturbative Lindhard response function is found for an electron system in a sinusoidal potential.

S P Corney, P D Jarvis, I Tsohantjis, D S McAnally

The exceptional superalgebra $\D21a$ has been classified as a candidate conformal supersymmetry algera in two dimensions. We propose an alternative interpretation of it as an extended BFV-BRST quantisation superalgebra in 2D ($D(2,1;1) \simeq osp(2,2|2)$). A superfield realization is presented wherein the standard extended phase space coordinates can be iden

P D Jarvis, K S Fienberg

Superfield expansions over four-dimensional graded spacetime $(x^μ,θ^ν)$, with Minkowski coordinates $x$ extended by vector Grassmann variables $θ$, are investigated. By appropriate identification of the physical Lorentz algebra in the even and odd parts of the superfield, a typology of `schizofields' containing both integer and half-integer spin fields

Aharon Nudelman

Certain linear objects, termed physical lines, are considered, and initial assumptions concerning their properties are introduced. A closed physical line in the form of a circle, termed J-string, is singled out for investigation. It is shown that this curve consists of indivisible line segments of length $\ell_Δ$. It is assumed that a J-string has an angular

Laura Andrianopoli, Francesco Cordaro, Pietro Fre', Leonardo Gualtieri

The recent construction of the non-semisimple gaugings of maximal D=5 supergravity is reported here. This construction is worked out in the so-called rheonomic approach, based on Free Differential Algebras and the solution of their Bianchi identities. In this approach the dualization mechanism between one-forms and two-forms is more transparent. The lagrangi

S. James Gates,, Marcus T. Grisaru, Marcia E. Knutt, Silvia Penati

We discuss features of the 4D, N = 1 WZNW term expressed as a function of chiral superfields and defined in a manner appropriate to calculate phenomenological matrix elements.

Tai-Fu Feng, Xue-Qian Li

With the on-shell renormalization scheme, we discuss neutrino masses up to one-loop approximation in the Supersymmetry without lepton number conservation and R-parity. Ii is shown that in this model with experimentally allowed parameters, $Δm^2_{23}, Δm^2_{12}$ and the mixing angles $|\sinθ{23}|,|\sinθ_{12}|$ which are consistent with the present observation

A. V. Kotikov, G. Parente

We investigate the Q^2 evolution of parton distributions at small x values, obtained in the case of flat initial conditions. The contributions of twist-two and (renormalon-type) higher-twist operators of the Wilson operator product expansion are taken into account. The results are in excellent agreement with deep inelastic scattering experimental data from H

Lev Kofman

This contribution to the proceedings collects new recent results on preheating after inflation. We discuss tachyonic preheating in the SUSY motivated hybrid inflation; development of equilibrium after preheating; theory of fermionic preheating and the problem of gravitino overproduction from preheating.

A. Pich

The leptonic decays of the tau lepton provide relevant tests on the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic tau decay modes constitute an ideal tool for studying low--energy effects of the strong interaction in very clean conditions. Accurate determinations of the QCD coupling and the strange q

Alexandre A. Osipov, Brigitte Hiller

We present a derivation of the low-energy effective meson Lagrangian of the Nambu -- Jona-Lasinio (NJL) model on the basis of Schwinger's proper-time regularization of the one-loop fermion determinant. We consider the case in which the $SU(2)\times SU(2)$ chiral symmetry of the NJL Lagrangian is broken by the current quark mass matrix with $\hat{m}_u\ne\

Kari Enqvist, Kimmo Kainulainen, Antti Sorri

We consider active-sterile neutrino oscillations in the early universe in an inhomogeneous isocurvature background. We show that very small initial baryonic seed-inhomogeneities can trigger a growth of very large amplitude spatial fluctuations in lepton asymmetry. Domains of varying asymmetry are observed to persist for a long time despite dissipative effect

HM Chan

Apart from offering explanations not only for the distinctive fermion mass and mixing patterns but also for the actual values of the mass and mixing parameters, the dual colour solution to the generation puzzle gives numerous detailed predictions ranging from rare FCNC meson decays and $μ$-$e$ conversions in nuclei at low energies to cosmic ray air showers w

J. -M. Levy

In a two flavour world, the usual equal $p$, equal $E$, or equal $v$ assumptions used to derive the neutrino oscillation length can be replaced by a specific definition of the velocity of the oscillating state which, unlike those assumptions, is compatible with exact production kinematics. This definition is further vindicated by the analysis of $π_{μ2}$ dec

D. V. Shirkov

The connection between ghost-free formulations of RG-invariant perturbation theory in the both Euclidean and Minkowskian regions is studied. Our basic tool is the "double spectral representation", similar to definition of Adler function, that stems from first principles of local QFT. It relates real functions defined in the Euclidean and Minkowskian

M. Hirai, H. Kobayashi, M. Miyama

We study parametrization of polarized parton distribution functions in the α_s leading order (LO) and in the next-to-leading order (NLO). From χ^2 fitting to the experimental data on A_1, optimum polarized distribution functions are determined. The quark spin content ΔΣis very sensitive to the small-x behavior of antiquark distributions which suggests that s

M. Kawasaki, K. Kohri, Takeo Moroi

We consider the effects on big bang nucleosynthesis (BBN) of the radiative decay of a long-lived massive particle. If high-energy photons are emitted after the BBN epoch ($t \sim 1 - 10^3$ sec), they may change the abundances of the light elements through photodissociation processes, which may result in a significant discrepancy between standard BBN and obse

D. Black, A. H. Fariborz, S. Moussa, S. Nasri

The three flavor linear sigma model is studied as a ``toy model'' for understanding the role of possible light scalar mesons in the ππ, πK and πηscattering channels. The approach involves computing the tree level partial wave amplitude for each channel and unitarizing by a simple K-matrix prescription which does not introduce any new parameters. If t

Bing An Li

The axial-vector couplings of the internediate bosons with fermions lead to the prediction of three very heavy spin-0 states in the SM, whose masses are about 10^{14}GeV. If these states on mass shell there are problems of negative probability. A new perturbation theory of the SM is proposed.

B. Lucini, M. Teper

We calculate the k=2 string tensions in SU(4) and SU(5) gauge theories in 3+1 dimensions, and compare them to the k=1 fundamental string tensions. We find, from the continuum extrapolation of our lattice calculations, that K(k=2)/K(k=1) = 1.40(8) in the SU(4) gauge theory, and that K(k=2)/K(k=1) = 1.56(10) in SU(5). We remark upon the way this might constrai

P. C. Rowson, M. Woods

We discuss the ultimate precision for ALR, and therefore for the weak mixing angle, at a high-luminosity Linear Collider. Drawing on our experience at the SLC, and considering various machine parameter sets for the NLC and for TESLA, it emerges that a compromise between peak luminosity and precision will be a likely outcome. This arises due to the severe req

G. Bonvicini, CLEO Collaboration

We have searched for CP-violating asymmetries in neutral charm meson decays in 13.7 fb^-1 of e^+e^- collision data at sqrt{s} = 10.6 GeV with the CLEO detector. The measured asymmetries in the rate of D0 and D0bar decays to K0sPi0, Pi0Pi0 and K0sK0s final states are (+0.1 +- 1.3)%, (+0.1 +- 4.8)% and (-23 +- 19)%, respectively.

H1 Collaboration, C. Adloff

A precise measurement of the inclusive deep-inelastic e^+p scattering cross section is reported in the kinematic range 1.5<= Q^2 <=150 GeV^2 and 3*10^(-5)<= x <=0.2. The data were recorded with the H1 detector at HERA in 1996 and 1997, and correspond to an integrated luminosity of 20 pb^(-1). The double differential cross section, from which the proton struc

H1 Collaboration, C. Adloff

The inclusive e^-p single and double differential cross sections for neutral and charged current processes are measured with the H1 detector at HERA, in the range of four-momentum transfer squared Q^2 between 150 and 30000 GeV^2, and Bjorken x between 0.002 and 0.65. The data were taken in 1998 and 1999 with a centre-of-mass energy of 320 GeV and correspond

H1 Collaboration, C. Adloff

A measurement is presented of dijet and 3-jet cross sections in low-|t| diffractive deep-inelastic scattering interactions of the type ep -> eXY, where the system X is separated by a large rapidity gap from a low-mass baryonic system Y. Data taken with the H1 detector at HERA, corresponding to an integrated luminosity of 18.0 pb^(-1), are used to measure had

Oleg V. Kechkin

A new Lagrange formalism based on the use of a single scalar (d+1)X(d+1+n) matrix potential is developed for the low-energy heterotic string theory with n U(1) gauge fields compactified from d+3 to 3 dimensions on a torus. This formalism also includes three pairs on-shell defined scalar and vector matrix potentials of the dimensions (d+1)X(d+1), (d+1)X(d+1+n

T. P. Singh

There are models of gravitational collapse in classical general relativity which admit the formation of naked singularities as well as black holes. These include fluid models as well as models with scalar fields as matter. Even if fluid models were to be regarded as unphysical in their matter content, the remaining class of models (based on scalar fields) ge

J. P. Mbelek, M. Lachieze-Rey

We show that the principle of least action is generally inconsistent with the usual Kaluza-Klein program, the higher dimensional Einstein-Hilbert action being unbounded from below. This inconsistency is also present in other theories with higher dimensions like supergravity. Hence, we conclude to the necessity of an external scalar field to compensate this f

Hongsong Chou

The three Power-Laws proposed by Faloutsos et al(1999) are important discoveries among many recent works on finding hidden rules in the seemingly chaotic Internet topology. In this note, we want to point out that the first two laws discovered by Faloutsos et al(1999, hereafter, {\it Faloutsos&#39; Power Laws}) are in fact equivalent. That is, as long as any

James Harland, David Pym

We consider the problem of searching for proofs in sequential presentations of logics with multiplicative (or intensional) connectives. Specifically, we start with the multiplicative fragment of linear logic and extend, on the one hand, to linear logic with its additives and, on the other, to the additives of the logic of bunched implications, BI. We give an

J. Doyne Farmer, Shareen Joshi

A deterministic trading strategy can be regarded as a signal processing element that uses external information and past prices as inputs and incorporates them into future prices. This paper uses a market maker based method of price formation to study the price dynamics induced by several commonly used financial trading strategies, showing how they amplify no

Kerson Huang

The Bose-Einstein condensates recently created in trapped atomic gases are mesoscopic systems, in two senses: (a) Their size fall between macroscopic and microscopic systems; (b) They have a quantum phase that can be manipulated in experiments. We review the theoretical and experimental facts about trapped atomic gases, and give examples that emphasize their

A. D. Mirlin, E. Tsitsishvili, P. Woelfle

An analytical study of the low-field magnetoresistance of a two-dimensional electron gas subject to a weak periodic modulation is presented. We assume small-angle impurity scattering characteristic for high-mobility semiconductor heterostructures. It is shown that the condition for existence of the strong low-field magnetoresistance induced by so-called chan

A. Rinaldi, F. Sciortino, P. Tartaglia

We report extensive simulations of liquid supercooled states for a simple three-sites molecular model, introduced by Lewis and Wahnstr&#34;om [L. J. Lewis and G. Wahnstr&#34;om, Phys. Rev. E 50, 3865 (1994)] to mimic the behavior of ortho-terphenyl. The large system size and the long simulation length allow to calculate very precisely --- in a large q-vector

C. A. A. de Carvalho, R. M. Cavalcanti, E. S. Fraga, S. E. Joras

We present a simple method to deal with caustics in the semiclassical approximation to the partition function of a one-dimensional quantum system. The procedure, which makes use of complex trajectories, is applied to the quartic double-well potential.

E. Burgos, H. Ceva, R. P. J. Perazzo

We study the dynamics of a generalized Minority Game (GMG) and of the Bar Attendance Model (BAM) in which a number of agents self-organize to match an attendance that is fixed externally as a control parameter. We compare the usual dynamics used for the Minority Game with one for the BAM that makes a better use of the available information. We study the asym

Yves Elskens

The jump processes W(t) on [0,\infty[ with transitions w -> alpha w at rate b*w^beta (0 =< alpha =< 1, b>0, beta>0) are considered. Their moments are shown to decay not faster than algebraically for t -> \infty, and an equilibrium probability density is found for a rescaled process U = (t + k)^{-beta} W. A corresponding birth process is discussed.

L. Kullmann, J. Kertesz

We consider a preferential growth model where particles are added one by one to the system consisting of clusters of particles. A new particle can either form a new cluster (with probability q) or join an already existing cluster with a probability proportional to the size thereof. We calculate exactly the probability $\Pm_i(k,t)$ that the size of the i-th c

S. E. Mangioni, R. R. Deza, H. S. Wio

We address a recently introduced model describing a system of periodically coupled nonlinear phase oscillators submitted to multiplicative white noises, wherein a ratchet-like transport mechanism arises through a symmetry-breaking noise-induced nonequilibrium phase transition. Numerical simulations of this system reveal amazing novel features such as negativ

Matthias J. Graf, Daryl. W. Hess

We explore the response of an unconventional superconductor to spatially inhomogeneous antiferromagnetism (SIAFM). Symmetry allows the superconducting order parameter in the E-representation models for UPt3 to couple directly to the AFM order parameter. The Ginzburg-Landau equations for coupled superconductivity and SIAFM are solved numerically for two possi

Angsula Ghosh, Sadhan K. Adhikari

We study the order parameter for mixed-symmetry states involving a major $d_{x^2-y^2}$ state and various minor s-wave states ($s$, $s_{xy}$, and $s_{x^2+y^2}$) for different filling and temperature for mixing angles 0 and $π/2$. We employ a two-dimensional tight-binding model incorporating second-neighbor hopping for tetragonal and orthorhombic lattice. Ther

V. Penna, M. Spera

The Poisson structure generating the hamiltonian dynamics of string vortices is reconstructed within the current algebra picture as a limiting case of the standard brackets associated to fluids with a smooth vorticity field. The approach implemented bypasses the use of Dirac&#39;s procedure. The fine structure of the dynamical algebra is derived for planar f

Anirban Chakraborti, Srutarshi Pradhan, Bikas K. Chakrabarti

We have studied here the self-organising features of the dynamics of a model market, where the agents `trade&#39; for a single commodity with their money. The model market consists of fixed numbers of economic agents, money supply and commodity. We demonstrate that the model, apart from showing a self-organising behaviour, indicates a crucial role for the mo

Tatsuo Shibata

We investigate nonequilibrium chemical reaction systems from the view point of steady state thermodynamics proposed by Oono and Paniconi [Prog. Theor. Phys. Suppl. 130, 29 (1998)]. The concentrations of some compounds are operated by an external system, so that a transition from a steady state to other steady state takes place. We show that an analogue of Cl

L. Didukh, O. Kramar, Yu. Skorenkyy

In the present work ferromagnetic ordering in the Hubbard model generalized by taking into account the inter-atomic exchange interaction and correlated hopping in partially filled narrow band is considered. In the case of weak electron-electron interaction the ground state energy and condition of ferromagnetic state realization are found using the Green func

V. Bobrovskii, A. Mirmelstein, A. Podlesnyak, I. Zhdakhin

Exact expressions for the parameters of Stevens Hamiltonian are derived within the framework of a specific model that assumes uniform character of charge density distribution in a certain direction over crystalline lattice. The new model is developed to strengthen the possibilities for analysis of experimental data obtained by inelastic neutron scattering. I

N. B. Kopnin

We review the basic ideas and results on the vortex dynamics in clean superfluid Fermi systems. The forces acting on moving vortices are discussed including the problem of the transverse force which was a matter of confusion for quite a time. Finally, we formulate the equations of the vortex dynamics which include all the forces and the inertial term associa

Yoshiyuki Fukumoto

Magnetization plateaus in the Shastry-Sutherland model for ${\rm SrCu_2(BO_3)_2}$ are studied by the perturbation expansion method. The fourth-order effective Hamiltonian which describes the dynamics of triplet dimers (TD&#39;s) with $S^{\rm tot}_z=1$ in the singlet sea is derived and then partially diagonalized for the space that consists of the TD configur

I. Tsukada, T. Yamamoto, M. Takagi, T. Tsubone

Ferromagnetism and accompanying large negative magnetoresistance in Pb-substituted Bi-Sr-Co-O misfit-layer compound are investigated in detail. Recent structural analysis of (Bi,Pb)${}_2$Sr${}_{3}$Co${}_2$O${}_9$, which has been believed to be a Co analogue of Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+δ}$, revealed that it has a more complex structure including a Co

A. V. Kolesnikov, K. B. Efetov

Using the supersymmetry technique combined with the transfer matrix method we calculate different physical quantities characterizing localization in disordered wires. In particular, we analyze the density-density correlation function and study effects of an external magnetic field $H$ on tails of wave functions. At zero and very strong magnetic fields, we ob

Nick Gorkavyi, Sara Heap, Leonid Ozernoy, Tanya Taidakova

Our efficient numerical approach has been applied to modeling the asymmetric circumstellar dust disk around Beta Pictoris as observed with the HST/STIS. We present a new model on the origin of the warping of the Beta Pic disk. We suggest that the observed warp is formed by the gravitational influence of a planet with a mass of about 10 masses of Earth, at a

H. Baumgardt

We study the evolution of the galactic globular cluster system to determine its initial mass-function and the fraction of halo stars that could have come from disrupted globular clusters. We study the cluster evolution under the influence of two destruction mechanisms: Two-body relaxation and dynamical friction. New results of N-body simulations are used for

G. Fossati

We discuss the preliminary results of an extensive effort to address the fundamental, and yet un-answered, question that can be trivialized as: ``are there more blue or red blazars?&#39;&#39;. This problematic is tightly connected with the much debated issue of the unified picture(s) of radio-loud AGNs, which in turn revolves around the existence, and the pr

S. Amari, X. Gao, L. N. Nittler, E. Zinner

We report the discovery of five SiC grains and one graphite grain isolated from the Murchison carbonaceous meteorite whose major-element isotopic compositions indicate an origin in nova explosions. The grains are characterized by low 12C/13C (4-9) and 14N/15N (5-20) ratios, large excesses in 30Si (30Si/28Si ratios range to 2.1 times solar) and high 26Al/27Al

Taku Takeuchi, Pawel Artymowicz

We analyze the dynamics of gas-dust coupling in the presence of stellar radiation pressure in circumstellar gas disks, which are in a transitional stage between the gas-dominated, optically thick, primordial nebulae, and the dust-dominated, optically thin Vega-type disks. Dust undergo radial migration, seeking a stable equilibrium orbit in corotation with ga

Paul J Groot, Rene&#39; G. M. Rutten, Jan van Paradijs

We present low-resolution spectrophotometric optical observations of the eclipsing nova-like cataclysmic variable SW Sex, the prototype of the SW Sex stars. We observed the system when it was in an unusual low state. The spectrum is characterized by the presence of strong He II and C IV emission lines as well as the normal single peaked Balmer emission lines

Preeti Kharb, Prajval Shastri

A majority of a complete sample of 3CR FR I radio galaxies show unresolved optical nuclear sources on the scales of 0.1 arcsec. About half of the 3CR FR II radio galaxies observed with the HST also show Compact Central Cores (CCC). These CCCs have been interpreted as the optical counterparts of the non-thermal radio cores in these radio galaxies (Chiaberge,

Anvar Shukurov

Observational evidence for dynamo action in spiral galaxies is reviewed, and the capabilities of various theories in explaining the basic features of galactic magnetic fields are discussed. Mean-field dynamo models appear to be unique in providing a coherent explanation of a wide variety of magnetic features in spiral galaxies. Reliable modelling of global m

R. G. Gratton, P. Bonifacio, A. Bragaglia, E. Carretta

High dispersion spectra (R>40,000) for a quite large number of stars at the main sequence turn-off and at the base of the subgiant branch in NGC6397 and NGC6752 were obtained with the UVES on Kueyen (VLT UT2). The [Fe/H] values we found are -2.03+/-0.02+/-0.04 and -1.42+/-0.02+/-0.04 for NGC6397 and NGC6752 respectively, where the first error bars refer to i

R. P. Saglia, Matthew Colless, David Burstein, Roger L. Davies

The EFAR project is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. Here we describe the maximum likelihood algorithm we developed to investigate the correlations between the parameters of the EFAR database. One-, two-, and three-dimensional gaussian models are constructed to determine the mean value and

Enrico Cappellaro, Massimo Turatto

We review the basic properties of the different supernova types identified in the current taxonomy, with emphasis on the more recent developments. To help orienting in the variegate zoo, the optical photometric and spectroscopic properties of the different supernova types are presented in a number of summary figures. We also report the latest estimates of th

Christopher J. Conselice

I review the properties of starburst galaxies in the nearby and distant universe to decipher their evolution as a distinct extragalactic class. The physical processes and environments of massive star-formation appear to be similar out to z = 4, although the modes of triggering are likely quite different, varied, and still evolving. This is argued with the us

S. G. Djorgovski, A. A. Mahabal, R. J. Brunner, R. R. Gal

Systematic exploration of the observable parameter space, covered by large digital sky surveys spanning a range of wavelengths, will be one of the primary modes of research with a Virtual Observatory (VO). This will include searches for rare, unusual, or even previously unknown types of astronomical objects and phenomena, e.g. as outliers in some parameter s

Michael R. Garcia, Jeffrey E. McClintock, Ramesh Narayan, Paul Callanan

Previously we claimed that Black Hole X-ray Novae (BHXN) in quiescence are much less luminous than equivalent Neutron Star X-ray Novae (NSXN). This claim was based on the quiescent detection of a single short period BHXN (A0620-00, P(orb)=7.8 hrs) and two longer period BHXN (GRO J1655-40, P(orb)=62.9 hrs; V404 Cyg, P(orb)=155.3 hrs), along with sensitive upp

Kazuhiro Yamamoto, Hiroaki Nishioka, Atsushi Taruya

We revisit the feasibility of a cosmological test with the geometric distortion focusing on an ambiguous factor of the evolution of bias. Starting from defining estimators for the spatial two-point correlation function and the power spectrum, in a rigorous manner, we derive useful formulas for the two-point clustering statistics which take the light-cone eff

Benjamin D. Wandelt

In this talk I propose the first fast methods which can analyze CMB data taking into account correlated noise, arbitrary beam shapes, non-uniform distribution of integration time on the sky, and partial sky coverage, without the need for approximations. These ring torus methods work by performing the analysis in the time ordered domain (TOD) rather than on t

M. T. Murphy, J. K. Webb, V. V. Flambaum, V. A. Dzuba

An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar absorption line spectra with laboratory spectra provides a sensitive probe for variability of the fine structure constant, alpha, over cosmological time-scales. We have previously developed and applied

G. Lhersonneau, B. Pfeiffer, H. Gabelmann, K. -L. Kratz

The decay of the very neutron-rich nucleus Rb-100 has been studied by gamma-spectroscopy of on-line mass-separated samples. Schemes for beta-decay to Sr-100 and beta-n-decay to Sr-99 are presented. New sets of transitions in Sr-99 and Sr-100 with identical energies are observed. All identical bands so far observed in neutron-rich Sr isotopes obey a simple en

Ulf H. Danielsson, Alberto Guijosa, Martin Kruczenski

Recently it was shown that NCOS theories are part of a ten-dimensional theory known as Non-relativistic Wound string theory. We clarify the sense in which gravity is present in this theory. We show that Wound string theory contains exceptional unwound strings, including a graviton, which mediate the previously discovered instantaneous long-range interactions

E. Ivanov, S. Krivonos, O. Lechtenfeld, B. Zupnik

We construct low-energy Goldstone superfield actions describing various patterns of the partial spontaneous breakdown of two-dimensional N=(1,1), N=(2,0) and N=(2,2) supersymmetries, with the main focus on the last case. These nonlinear actions admit a representation in the superspace of the unbroken supersymmetry as well as in a superspace of the full super

Per Kraus, Finn Larsen

We develop the boundary string field theory approach to tachyon condensation on the DDbar system. Particular attention is paid to the gauge fields, which combine with the tachyons in a natural way. We derive the RR-couplings of the system and express the result in terms of Quillen&#39;s superconnection. The result is related to an index theorem, and is thus

Valery Telnov

A high energy photon collider (gamma-gamma, gamma-electron) based on backward Compton scattering of laser light is a very natural supplement to e+e- a linear collider and can significantly enrich the physics program. The region below about one 0.5-1 TeV is very convenient from a technical point of view: wave length of the laser should be about 1 micron, i.e.

Henrique Boschi-Filho, Nelson R. F. Braga

Compactified AdS space can not be mapped into just one Poincare coordinate chart. This implies that the bulk field spectrum is discrete despite the infinite range of the coordinates. We discuss here why this discretization of the field spectrum seems to be a necessary ingredient for the holographic mapping. For the Randall Sundrum model we show that this dis

Jan W. Kantelhardt, Yosef Ashkenazy, Plamen Ch. Ivanov, Armin Bunde

We study correlation properties of the magnitude and the sign of the increments in the time intervals between successive heartbeats during light sleep, deep sleep, and REM sleep using the detrended fluctuation analysis method. We find short-range anticorrelations in the sign time series, which are strong during deep sleep, weaker during light sleep and even

Hongsong Chou

We apply a Fourier spectral numerical method to 3D incompressible MHD turbulence with a magnetic Prandtl number $Pr \geq 1$. We examine the processes by which an initially weak, large-scale seed magnetic field and an initially weak, small-scale, impulse-like seed magnetic field are amplified. We find that in both cases the magnetic energy spectrum grows at a

D. E. MacLaughlin, O. O. Bernal, R. H. Heffner, G. J. Nieuwenhuys

Local f-electron spin dynamics in the non-Fermi-liquid heavy-fermion alloys UCu_{5-x}Pd_x, x = 1.0 and 1.5, have been studied using muon spin-lattice relaxation. The sample-averaged asymmetry function Gbar(t) indicates strongly inhomogeneous spin fluctuations, and exhibits the scaling Gbar(t,H) = Gbar(t/H^γ) expected from glassy dynamics. At 0.05 K γ(x=1.0)

A. I. Davydychev, M. Yu. Kalmykov

For certain dimensionally-regulated one-, two- and three-loop diagrams, problems of constructing the epsilon-expansion and the analytic continuation of the results are studied. In some examples, an arbitrary term of the epsilon-expansion can be calculated. For more complicated cases, only a few higher terms in epsilon are obtained. Apart from the one-loop tw

Jerome P. Gauntlett, Nakwoo Kim, Daniel Waldram

We construct supergravity solutions dual to the twisted field theories arising when M-theory fivebranes wrap general supersymmetric cycles. The solutions are constructed in maximal D=7 gauged supergravity and then uplifted to D=11. Our analysis covers Kahler, special Lagrangian and exceptional calibrated cycles. The metric on the cycles are Einstein, but do

J. Lorenzo Diaz-Cruz, Hitoshi Murayama, Aaron Pierce

We investigate three different possibilities for improving the fermion mass relations that arise in grand unified theories (GUTs). Each scenario relies on supersymmetric loop effects alone, without modifying the naive Yukawa unification. First, we consider A-terms that follow the usual proportionality condition. In this case SUSY effects can improve the mass

T. Hahn

This paper describes the Mathematica package FeynArts used for the generation and visualization of Feynman diagrams and amplitudes. The main features of version 3 are: generation of diagrams at three levels, user-definable model files, support for supersymmetric models, and publication-quality Feynman diagrams in PostScript or LaTeX.

D0 collaboration, B. Abbott

Results are presented from analyses of jet data produced in pbarp collisions at sqrt{s} = 630 and 1800 GeV collected with the DO detector during the 1994-95 Fermilab Tevatron Collider run. We discuss details of detector calibration, and jet selection criteria in measurements of various jet production cross sections at sqrt{s} = 630 and 1800 GeV. The inclusiv

Yurii A. Neretin

Consider a finite dimensional (generally reducible) polynomial representation ρof GL_n. A projective compactification of GL_n is the closure of ρ(GL_n) in the space of all operators defined up to a factor (this class of spaces can be characterized as equivariant projective normal compactifications of GL_n). We give an expicit description for all projective c

Attilio Cucchieri, Daniel Zwanziger

We report a numerical study of SU(2) lattice gauge theory in the minimal Coulomb gauge at beta = 2.2 and 9 different volumes. After extrapolation to infinite volume, our fit agrees with a lattice discretization of Gribov&#39;s formula for the transverse equal-time would-be physical gluon propagator, that vanishes like |k| at k = 0, whereas the free equal-tim

G. M. Kavoulakis

We present a parameter-free model which estimates the density of excitons in Cu$_2$O, related to experiments that have tried to create an excitonic Bose-Einstein condensate. Our study demonstrates that the triplet-state excitons move along adiabats and obey classical statistics, while the singlet-state excitons are a possible candidate for forming a Bose-Ein

P. Castelo Ferreira, Ian I. Kogan

We study open and unoriented strings in a Topological Membrane (TM) theory through orbifolds of the bulk 3D space. This is achieved by gauging discrete symmetries of the theory. Open and unoriented strings can be obtained from all possible realizations of $C$, $P$ and $T$ symmetries. The important role of $C$ symmetry to distinguish between Dirichlet and Neu

Björn Brinne, Ansar Fayyazuddin, Tasneem Zehra Husain, Douglas J. Smith

We describe how to construct solutions to 11-dimensional supergravity corresponding to M5-branes wrapped on holomorphic 2-cycles embedded in C^3. These solutions preserve N=1 supersymmetry in four dimensions. In the near-horizon limit they are expected to be dual to N=1 large N gauge theories in four dimensions by Maldacena's duality.