July 1997 arXiv papers — page 17

Ivan Babenko, Mikhail Katz

In 1972, Marcel Berger defined a metric invariant that captures the `size' of k-dimensional homology of a Riemannian manifold. This invariant came to be called the k-dimensional SYSTOLE. He asked if the systoles can be constrained by the volume, in the spirit of the 1949 theorem of C. Loewner. We construct metrics, inspired by M. Gromov's 1993 exampl

I. Cabrera, H. Perez Rojas

A mechanism generating a $λ$-type behavior in the specific heat of a Bose gas near the critical temperature $T_c$ is discussed. It is shown to work for a general class of quasiparticle spectra, and especially, for the Bogoliubov's model of a weakly interacting Bose gas, where a temperature-dependent quasi-particle spectrum is obtained.

C. S. O'Hern, Randall D. Kamien, T. C. Lubensky, Philip Nelson

We present an elastic model of B-form DNA as a stack of thin, rigid plates or base pairs that are not permitted to deform. The symmetry of DNA and the constraint of plate rigidity limit the number of bulk elastic constants contributing to a macroscopic elasticity theory of DNA to four. We derive an effective twist-stretch energy in terms of the macroscopic s

Yu. G. Makhlin

We calculate Ohmic and Hall flux flow conductivities in the mixed state of d-wave superconductors taking into account the spectral flow along the anomalous branch of the states bound to vortex cores. Three regimes of vortex dynamics are found. In the moderately clean limit the contribution of the spectral flow to the conductivities coincides with that for s-

Anandamohan Ghosh, B. C. Gupta, K. Kundu

We investigate the effect of a nondegenerate quadratic nonlinear dimeric impurity on the formation of stationary localized states in one dimensional systems. We also consider the formation of stationary localized states in a fully nonlinear system where alternative sites have same nonlinear strengths. Appropriate ansatzs have been chosen for all the cases wh

O. Gunnarsson, E. Koch

A discrete Hubbard-Stratonovich transformation is presented for systems with an orbital degeneracy $N$ and a Hubbard Coulomb interaction without multiplet effects. An exact transformation is obtained by introducing an external field which takes $N+1$ values. Alternative approximate transformations are presented, where the field takes fewer values, for instan

C. Castellano, F. Corberi, M. Zannetti

The origin of the non commutativity of the limits $t \to \infty$ and $N \to \infty$ in the dynamics of first order transitions is investigated. In the large-N model, i.e. $N \to \infty$ taken first, the low temperature phase is characterized by condensation of the large wave length fluctuations rather than by genuine phase-ordering as when $t \to \infty$ is

Ju. M. Khalack, V. M. Loktev, A. B. Nadtochii, I. V. Ostrovskii

The sonoluminescence of ionic semiconductors were studied. The main attention is paid to threshold phenomena which accompany the light irradiation, namely --- point defect creation and nonlinear ultrasound wave attenuation. The model for description of processes under investigation which connects the sonoluminescence excitation with the onset of point defect

Takuya Okabe

We present a general model which includes the ferromagnetic Kondo lattice and the Hubbard model as special cases. The stability of the ferromagnetic state is investigated variationally. We discuss the mechanism of ferromagnetism in metallic nickel, emphasizing the importance of orbital degeneracy and the effect of the Hund's-rule coupling.

Ming-Che Chang, Hsin-Fei Meng

When the energy of a pump wave is in resonance with the exciton creation energy, the electric susceptibility of a conjugated polymer in response to the probe wave is altered by the exciton gas. In this paper, we calculate the dependence of this change on the the exciton populations by the equation of motion (EOM) method. The magnitude of optical nonlinearity

E. Demler, A. J. Berlinsky, C. Kallin, G. B. Arnold

We consider proximity effect coupling in Superconducting/Antiferromagnetic/Superconducting (S-A-S) sandwiches using the recently developed SO(5) effective theory of high temperature superconductivity. We find that, for narrow junctions, the A region acts like a strong superconductor, and that there is a critical junction thickness which depends on the effect

Hiroshi Kontani, Kosaku Yamada

Magnetic susceptibility in a heavy fermion systemis composed of the Pauli term (χ_P) and the Van-Vleck term (χ_V). The latter comes from the interband excitation, where f-orbital degeneracy is essential. In this work, we study χ_P and χ_V in the orbitally degenerate (J=5/2) periodic Anderson model for both the metallic and insulating cases. The effect of the

Mark Dras

This paper develops a computational model of paraphrase under which text modification is carried out reluctantly; that is, there are external constraints, such as length or readability, on an otherwise ideal text, and modifications to the text are necessary to ensure conformance to these constraints. This problem is analogous to a mathematical optimisation p

Steffen D. Frischat, Eyal Doron

We study quantum-mechanical tunneling in mixed dynamical systems between symmetry-related phase space tori separated by a chaotic layer. Considering e.g. the annular billiard we decompose tunneling-related energy splittings and shifts into sums over paths in phase space. We show that tunneling transport is dominated by chaos-assisted paths that tunnel into a

W. E. Harris, P. R. Durrell, G. R. Petitpas, T. M. Webb

We present the first color-magnitude study for Palomar 2, a distant and heavily obscured globular cluster near the Galactic anticenter. Our (V,V-I) color-magnitude diagram (CMD), obtained with the UH8K camera at the CFHT, reaches V(lim) = 24 and clearly shows the principal sequences of the cluster, though with substantial overall foreground absorption and di

W. E. Harris, R. A. Bell, D. A. VandenBerg, M. Bolte

The WFPC2 camera on HST has been used to obtain deep main sequence photometry of the low-metallicity ([Fe/H]=-2.14), outer-halo globular cluster NGC 2419. A differential fit of the NGC 2419 CMD to that of the similarly metal-poor \ standard cluster M92 shows that they have virtually identical principal sequences and thus the same age to well within 1 Gyr. Si

Francesco R. Ferraro, Barbara Paltrinieri, Flavio Fusi Pecci, Robert T. Rood

The core of the galactic globular cluster M13 (NGC 6205) has been observed with WFPC2 on the Hubble Space Telescope through visual, blue and mid- and far-UV filters in a programme devoted to study the UV population in a sample of Galactic globular clusters. In the UV Color Magnitude Diagrams derived from the HST images we have discovered three faint objects

R. P. Fender

New radio observations of the radio-jet X-ray binary Circinus X-1 over nearly an entire 16.6-day orbit are presented. The source continues to undergo radio flaring in the phase interval 0.0 - 0.2 and appears to be brightening since observations in the early 1990s. The radio flux density is well correlated with simultaneous soft X-ray monitoring from the XTE

Bernhard Geiger, Peter Schneider

Analysing the weak lensing distortions of the images of faint background galaxies provides a means to constrain the average mass distribution of cluster galaxies and potentially to test the extent of their dark matter haloes as a function of the density of their environment. The observable image distortions are a consequence of the interplay between the effe

M. Orlandini, D. Dal Fiume, L. Nicastro, S. Giarrusso

We report on the spectral (pulse averaged) and timing analysis of the ~ 20 ksec observation of the X-ray binary pulsar Vela X-1 performed during the BeppoSAX Science Verification Phase. The source was observed in two different intensity states: the low state is probably due to an erratic intensity dip and shows a decrease of a factor ~ 2 in intensity, and a

Gustavo A. Medina Tanco, Elisabete M. de Gouveia Dal Pino, Jorge E. Horvath

We report the results of 3D simulations of the trajectories of ultra-high energy protons and Fe nuclei (with energies $E = 4 \times 10^{19}$ and $2.5 \times 10^{20} eV$) propagating through the galactic magnetic field from the sources to the detector. A uniform distribution of anti-particles is backtracked from the detector, at the Earth, to the halo of the

A. G. A. Brown, F. Arenou, F. van Leeuwen, L. Lindegren

This contribution is intended as a `rough guide' to the Hipparcos Catalogue for the non-expert user. Some general aspects of the use of astrometric data are discussed as well as Hipparcos-specific applications. We discuss when and at what level one may expect systematic errors to occur in the Hipparcos Catalogue. Next we discuss the question of the inter

G. German, Yu Jiang

Following recent work by Lambiase and Nesterenko we study in detail the interquark potential for a Nambu-Goto string with point masses attached to its ends. We obtain exact solutions to the gap equations for the Lagrange multipliers and metric components and determine the potential without simplifying assumptions. We also discuss Lüscher term and argue that

Fiorenzo Bastianelli, Olindo Corradini

The 't Hooft anomaly matching conditions are a standard tool to study and test non-perturbative issues in quantum field theory. We give a new, simple proof of the anomaly matching conditions in 2D Poincare` invariant theories. We consider the case of invariance under a large class of generalized symmetries, which include abelian and non-abelian internal

Denis I. Golosov, Andrei E. Ruckenstein

We re-examine the calculation of the transverse spin-diffusion coefficient in a dilute degenerate spin-polarized Fermi gas, for the case of s-wave scattering. The special feature of this limit is that the dependence of the spin diffusion coefficient on temperature and field can be calculated explicitly with no further approximations. This exact solution unco

Geon Hyoung Lee, Jae Hyung Yee

We develop a systematic method of the perturbative expansion around the Gaussian effective action based on the background field method. We show, by applying the method to the quantum mechanical anharmonic oscillator problem, that even the first non-trivial correction terms greatly improve the Gaussian approximation.

Daniel J. H. Chung, Glennys R. Farrar, Edward W. Kolb

We investigate the possibility that cosmic rays of energy larger than the Greisen-Zatsepin-Kuzmin cutoff are not nucleons, but a new stable, massive, hadron that appears in many extensions of the standard model. We focus primarily on the S^0, a uds-gluino bound state. The range of the S^0 through the cosmic background radiation is significantly longer than t

Jonathan A. Bagger, Konstantin T. Matchev, Ren-Jie Zhang

We compute the leading QCD corrections to K-Kbar mixing in the supersymmetric standard model with general soft supersymmetry-breaking parameters. We construct the ΔS=2 effective Lagrangian for three hierarchies of supersymmetric particle masses, namely, when the gluino mass is comparable to, much greater than, or much less than the masses of the first two ge

Valery I. Rupasov

We derive thermodynamic Bethe ansatz equations for a model describing an $U\to\infty$ Anderson impurity embedded in a BCS superconductor. The equations are solved analytically in the zero-temperature limit, T=0. It is shown that the impurities depress superconductivity in the Kondo limit, however at T=0 the system remains in the superconducting state for any

A. Gehrmann-De Ridder, E. W. N. Glover

We present a complete calculation of the photon +~1 jet rate in $e^+e^-$ annihilation up to ${\cal O}(αα_{s})$. Although formally of next-to-leading order in perturbation theory, this calculation contains several ingredients appropriate to a next-to-next-to-leading order calculation of jet observables. In particular, we describe a generalization of the commo

A. Petrelli, M. Cacciari, M. Greco, F. Maltoni

We present a calculation of next-to-leading-order (NLO) QCD corrections to total hadronic production cross sections and to light-hadron-decay rates of heavy quarkonium states. Both colour-singlet and colour-octet contributions are included. We discuss in detail the use of covariant projectors in dimensional regularization, the structure of soft-gluon emissio

R. Banerjee, E. C. Marino

We develop a new approach for bosonization based on the direct comparison of current correlation functions and apply it to the case of the Massive Thirring Model in three dimensions in the weak coupling regime, but with an arbitrary mass. Explicit bosonized forms for the lagrangian and the current are obtained in terms of a vector gauge field. Exact results

Eli Dwek

We present models for the evolution of the elemental abundances in the gas and dust phases of the interstellar medium (ISM) of our Galaxy by generalizing standard models for its dynamical and chemical evolution. In these models, the stellar birthrate history is determined by the infall rate of primordial gas, and by its functional dependence on the mass surf

L. T. Handoko

I examine a possibility to extract the angle $γ$ of the Cabibbo-Kobayashi-Maskawa unitarity triangle by the inclusive $B \to X_d ł^+ ł^- $ decay. An independent information for the angle is expected from the non-trivial contribution induced in $u \bar{u}$ and $c \bar{c}$ loops. The contributions induce CP asymmetry which has high sensitivity to the angle $γ$

C. Adloff

Low x deep-inelastic ep scattering data, taken in 1994 at the H1 detector at HERA, are analysed in the Breit frame of reference. The evolution of the peak and width of the current hemisphere fragmentation function is presented as a function of Q and compared with e+e- results at equivalent centre of mass energies. Differences between the average charged mult

Sanatan Digal, Supratim Sengupta, Ajit M. Srivastava

We carry out numerical simulation of the formation of U(1) global vortices in a first order phase transition in 2+1 dimensions in the presence of small explicit symmetry breaking. Bubbles of broken symmetry phase are randomly nucleated, which grow and coalesce. Vortices form at junctions of bubbles via standard Kibble mechanism as well as due to a new mechan

P. Singha Deo, V. A. Schweigert, F. M. Peeters, A. K. Geim

Solutions of Ginzburg-Landau eqns. coupled with three dimensional Maxwell eqns. reveal intriguing magnetic response of small superconducting particles, qualitatively different from the two dimensional approximation but in agreement with recent experiments. Depending on the radius and thickness first or second order transitions are found for the normal to sup

Erwin Frey, Klaus Kroy, Jan Wilhelm, Erich Sackmann

We review the physical properties of macromolecular networks, consisting of semiflexible polymers such as actin. We start by giving a theoretical analysis of the conformational statistics and mechanical response of single filaments. Experimentally relevant quantities such as the end-to-end distribution function and the force-extension relation are discussed.

M. Hirai, S. Kumano, M. Miyama

We investigate numerical solution of Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) Q^2 evolution equations for longitudinally polarized structure functions. Flavor nonsinglet and singlet equations with next-to-leading-order $α_s$ corrections are studied. A brute-force method is employed. Dividing the variables x and Q^2 into small steps, we simply solve

Keith Norton, George Jaroszkiewicz

We apply the principles discussed in earlier papers to the construction of discrete time quantum field theories. We use the Schwinger action principle to find the discrete time free field commutators for scalar fields, which allows us to set up the reduction formalism for discrete time scattering processes. Then we derive the discrete time analogue of the Fe

Keith Norton, George Jaroszkiewicz

We apply the principles of discrete time mechanics discussed in earlier papers to the first and second quantised Dirac equation. We use the Schwinger action principle to find the anticommutation relations of the Dirac field and of the particle creation operators in the theory. We find new solutions to the discrete time Dirac equation, referred to as oscillon

A. De Martino, M. Moriconi, G. Mussardo

The physical properties induced by a quenched surface magnetic field in the Ising model are investigated by means of boundary quantum field theory in replica space. Exact boundary scattering amplitudes are proposed and used to study the averaged quenched correlation functions.

Changhyun Ahn, Kyungho Oh, Radu Tatar

We study N=1 dualities in four dimensional supersymmetric gauge theories as the worldvolume theory of D4 branes with one compact direction in type IIA string theory. We generalize the previous work for SO(N_{c1}) x Sp(N_{c2}) with the superpotential W=Tr X^4 to the case of W= Tr X^4(k+1) in terms of brane configuration. We conjecture that the new dualities f

Shoichi Ichinose

Weyl Anomaly in the dilaton-scalar system in 2 dimensional gravity is examined. We take the heat-kernel regularization for the ultraviolet divergences. Generally the Weyl anomaly is determined by the 2nd order differential (elliptic) operator of the system and the definition of the measure. We have the freedom of the operator choice caused by the arbitrarine

D. K. Park, Sahng-Kyoon Yoo

The propagator of the spinless Aharonov-Bohm-Coulomb system is derived by following the Duru-Kleinert method. We use this propagator to explore the spin-1/2 Aharonov-Bohm-Coulomb system which contains a point interaction as a Zeeman term. Incorporation of the self-adjoint extension method into the Green's function formalism properly allows us to derive t

Carlos Castro

A local world volume Q-supersymmetric Weyl invariant Lagrangian for the membrane is presented. An analysis is provided which solves the problems raised by some authors in the past concerning the algebraic elimination of the auxiliary fields belonging to the coupling function supermultiplet. The starting bosonic action is the one given by Dolan and Tchrakian

Hisao Suzuki

We show how to evaluate the periods in Seiberg-Witten theories and in K3-fibered Calabi-Yau manifolds by using fibrations of the theories. In the Seiberg-Witten theories, it is shown that the dual pair of fields can be constructed from the classical fields in a simple form. As for Calabi-Yau manifolds which are fibrations of K3 surface, we obtain the solutio

David M. Kaplan, Jeremy Michelson

The moduli space metric for an arbitrary number of extremal D=5 black holes with arbitrary relatively supersymmetric charges is found.

V. V. Flambaum, F. M. Izrailev

The approach is developed for the description of isolated Fermi-systems with finite number of particles, such as complex atoms, nuclei, atomic clusters etc. It is based on statistical properties of chaotic excited states which are formed by the interaction between particles. New type of ``microcanonical'' partition function is introduced and expresse

C. J. Tymczak, G. S. Japaridze, C. R. Handy, Xiao-Qian Wang

We devise a new and highly accurate quantization procedure for the inner product representation, both in configuration and momentum space. Utilizing the representation $Ψ(ξ) = \sum_{i}a_i[E]ξ^i R_β(ξ)$, for an appropriate reference function, $R_β(ξ)$, we demonstrate that the (convergent) zeroes of the coefficient functions, $a_i[E] = 0$, approximate the exac

A. A. Andrianov, F. Cannata, D. N. Nishnianidze, M. V. Ioffe

A new supersymmetric approach to the analysis of dynamical symmetries for matrix quantum systems is presented. Contrary to standard one dimensional quantum mechanics where there is no role for an additional symmetry due to nondegeneracy, matrix hamiltonians allow for non-trivial residual symmetries. This approach is based on a generalization of the intertwin

G. A. Kotel'nikov

It is shown that the transformations of the charge conjugation in classical electrodynamics and in quantum theory can be interpreted as the consequences of the symmetry of Maxwell and Dirac equations with respect to the inversion of the speed of light: c to -c; t to t; (x,y,z) to (x,y,z), where c is the speed of light; t is the time; x, y, z are the spatial

Feng Xu

We show that the bases of irreducible integrable highest weight module of a non-symmetric Kac-Moody algebra, which is associated to a quiver with a nontrivial admissible automorphism, can be naturally identified with a set of certain invariant Langrangian irreducible subvarieties of certain varieties associated with the quiver defined by Nakajima. In the cas

P. Maris, C. D. Roberts, P. C. Tandy

Independent of assumptions about the form of the quark-antiquark scattering kernel we derive the explicit relation between the pion Bethe-Salpeter amplitude, Gamma_pi, and the quark propagator in the chiral limit; Gamma_pi necessarily involves a non-negligible gamma_5 gamma.P term (P is the pion four-momentum). We also obtain exact expressions for the pion d

Tatiana Alekseyevskaya

We consider a finite set $E$ of points in the $n$-dimensional affine space and two sets of objects that are generated by the set $E$: the system $Σ$ of $n$-dimensional simplices with vertices in $E$ and the system $Γ$ of chambers. The incidence matrix $A= \parallel a_{σ, γ}\parallel$, $σ\in Σ$, $γ\in Γ$, induces the notion of linear independence among simpli

Zheng Xiaoping, Li Jiarong

With asymptotic method developed from weak turbulent theory, the kinetic equations for QGP are expanded in fluctuation field potential $A^T_μ$. Considering the second-order and third-order currents, we derive the nonlinear permeability tensor function from Yang-Mills field equation, and find that the third-order current is more important in turbulent theory.

Jean-Bernard Zuber

The aim of this lecture is to present the concept of C-algebra and to illustrate its applications in two contexts: the study of reflection groups and their folding on the one hand, the structure of rational conformal field theories on the other. For simplicity the discussion is restricted to finite Coxeter groups and conformal theories with a $\hat{sl}(2)$ c

J. C. Perez Bueno

Jacobi brackets (a generalization of standard Poisson brackets in which Leibniz's rule is replaced by a weaker condition) are extended to brackets involving an arbitrary (even) number of functions. This new structure includes, as a particular case, the recently introduced generalized Poisson structures. The linear case on simple group manifolds is also s

J. Sonnenschein

We provide further evidence for the screening behavior of massless SU(N_c) bosonized QCD by (i) computing the potential between external quarks, (ii) bosonizing also the external sources and analyzing the states of the combined system and (iii) using an expansion in N_f- the number of flavors. We write down novel "non-abelian Schwinger like" solution

Stanislaw D. Glazek, Kenneth G. Wilson

We study a model of asymptotically free theories with bound states using the similarity renormalization group for hamiltonians. We find that the renormalized effective hamiltonians can be approximated in a large range of widths by introducing similarity factors and the running coupling constant. This approximation loses accuracy for the small widths on the o

Sahng-Kyoon Yoo, D. K. Park

It is shown that only the infinite angular momentum quantum states contribute to the incident wave in Aharonov-Bohm (AB) scattering. This result is clearly shown by recalculating the AB calculation with arbitrary decomposition of summation over the angular momentum quantum numbers in wave function. It is motivated from the fact that the pole contribution in

Zheng Xiaoping, Li Jiarong

We discuss the energy variation of a parton passing through a quark-gluon plasma(QGP) taking into account nonlinear polarization effect. We find the parton can be accelerated by fluctuations in QGP, which gives us a new physical insight about the response of QGP to such external the current.

U. van Kolck

The low-energy effective theory of nuclear physics based on chiral symmetry is reviewed. Topics discussed include the nucleon-nucleon force, few-body potentials, isospin violation, pion-deuteron scattering, proton-neutron radiative capture, pion photoproduction on the deuteron, and pion production in proton-proton collisions.

Zhen Cao, Xiao-Gang He, Bruce McKellar

Many explanations for the excess high-Q^2 $e^+p \to e^+X$ events from H1 and ZEUS at HERA have been proposed each with criticisms. We propose a new method to distinguish different models by looking at a new distribution which is insensitive to parton distribution function but sensitive to new physics.

S. V. Goloskokov, S. P. Kuleshov, O. V. Selyugin

Predictions of the elastic proton-proton cross sections at energies of LHC are calculate on the base of the high energy dynamical model. The growth of $ds/dt$ at fixed transfer momenta are shown. The form of eikonal of elastic hadron scattering at super high energies is discussed.

B. Blok

We pursue the issue of the local quark-hadron duality at high energies in two- and four-dimensional QCD. A mechanism of the dynamical realization of the quark-hadron duality in two-dimensional QCD in the limit of large number of colors, $N_c \to \infty$, (the ' t Hooft model) is investigated. We argue that a similar mechanism of dynamical smearing may be

Matthias Neubert

A critical review of the theoretical understanding of the lifetimes of beauty hadrons is given. A model-independent analysis using the heavy-quark expansion allows for a description of the lifetime ratios tau(B-)/tau(B0) and tau(Lambda_b)/tau(B0) in a small region of parameter space. It is demonstrated that the lifetime ratio tau(B-)/tau(B0) cannot be used t

Sanatan Digal, Ajit M. Srivastava

We discuss an outside-inside scenario for a first order quark-hadron transition in the Quark-Gluon Plasma (QGP) expected to be produced in heavy ion collisions, wherein the entire QGP region itself becomes like a subcritical bubble, and starts shrinking. We argue that this shrinking QGP bubble will lead to concentration of baryon number in a narrow beam like

H. Fritzsch, Z. Z. Xing

It is shown that the hierarchical structure of the quark mass terms in the standard model suggests a new description of the flavor mixing. The latter is primarily a heavy quark mixing involving the t and b quarks, followed by a mixing exclusively in the u-channel or the d-channel. The complex phase describing CP violation arises only in the light quark secto

E. Keith, Ernest Ma

If the recently discovered anomalous events at HERA are due to a scalar leptoquark, then it is very likely to have weak isospin $I = 1/2$. In that case, present precision measurements of the oblique radiative parameters $S$ and $T$ provide strong constraints on the mass of the other component of this doublet. If the standard model is extended to include such

C. A. Meyer

I will review the current status of exotic hadrons in the meson sector. There is currently strong evidence that a scalar glueball mixed into the normal scalar mesons has been found. There is also an interesting candidate for the tensor glueball state. Finally, I will discuss hybrid mesons with explicitly exotic quantum numbers.

K. K. Gan

This is a review of rare and forbidden decays of the $τ$ lepton. For the rare decays, this includes new results on the chiral anomaly decay $\taupietapio$, new upper limits on the second-class-current decay $\taupieta$, and the observations of the Cabibbo-suppressed decay $\tauketa$ and the internal conversion decay $\taueee$. For the forbidden decays, there

R. L. Saunders

Recent results from ZEUS for inclusive jet cross sections, dijet cross sections and dijet angular distributions are compared with NLO perturbative QCD calculations. The observation of isolated high $P_T$ photons (prompt photons) is also reported.

O. B. Zaslavskii

Nonextreme black hole in a cavity can achieve the extreme state with a zero surface gravity at a finite temperature on a boundary, the proper distance between the boundary and the horizon being finite. The classical geometry in this state is found explicitly for four-dimensional spherically-symmetrical and 2+1 rotating holes. In the first case the limiting g

Francois Goy

The conventional nature of synchronisation is discussed in inertial frames, where it is found that theories using different synchronisations are experimentally equivalent to special relativity. In contrary, in accelerated systems only a theory maintaining an absolute simultaneity is consistent with the natural behaviour of clocks. The principle of equivalenc

Francois Goy

The derivation of the transformations between inertial frames made by Mansouri and Sexl is generalised to three dimensions for an arbitrary direction of the velocity. Assuming lenght contraction and time dilation to have their relativistic values, a set of transformations kinematically equivalent to special relativity is obtained. The ``clock hypothesis'

Kjell Rosquist, Martin Goliath

The use of Lax pair tensors as a unifying framework for Killing tensors of arbitrary rank is discussed. Some properties of the tensorial Lax pair formulation are stated. A mechanical system with a well-known Lax representation -- the three-particle open Toda lattice -- is geometrized by a suitable canonical transformation. In this way the Toda lattice is rea

Silvio Rabello, Hiroshi Kohno, Eugene Demler, Shou-Cheng Zhang

We construct a class of microscopic electron models with exact SO(5) symmetry between antiferromagnetic and d-wave superconducting ground states. There is an exact one-to-one correspondence between both single-particle and collective excitations in both phases. SO(5) symmetry breaking terms can be introduced and classified according to irreducible representa

A. J. Ward, J. B. Pendry

In this paper we consider the application of electromagnetic theory to the analysis of the Scanning Near-field Optical Microscope (SNOM) in order to predict experimentally observable quantities such as the transmission or reflection coefficients for a particular tip-surface configuration. In particular we present the first application of a transfer matrix ba

M. L. Kulic, A. I. Buzdin, L. N. Bulaevskii

The recently reported coexistence of an oscillatory magnetic order with the wave vector Q=0.241 Å^{-1} and superconductivity in TmNi2B2C is analyzed theoretically. It is shown that the oscillatory magnetic order and superconductivity interact predominantly via the exchange interaction between localized moments (LM's) and conduction electrons, while the e

O. Golinelli

This paper discusses the enumeration of two-terminal series-parallel networks, i.e. the number of electrical networks built with n identical elements connected in series or parallel with two-terminal nodes. They frequently occur in applied probability theory as a model for real networks. The number of networks grows asymptotically like R^n/n^alpha, as for so

Tota Nakamura

The negative-sign problem in one-dimensional frustrated quantum spin systems is solved. We can remove negative signs of the local Boltzmann weights by using a dimer basis that has the spin-reversal symmetry. Validity of this new basis is checked in a general frustrated double-spin-chain system, namely the J_0-J_1-J_2-J_3 model. The negative sign vanishes per

Sang Boo Nam

A scenario which can account for all observed features of both high-$T_c$ superconductors (HTS) and low-$T_c$ superconductors (LTS) is discussed. This scenario is based on the fact that a finite pairing interaction energy range $T_d$ is required to have a finite value of $T_c$ and that not all carriers participate in pairings, yielding multiconnected superco

James M. Cordes, T. Joseph W. Lazio, Carl Sagan

We consider interstellar scintillations as a cause of intermittency in radio signals from extraterrestrial intelligence (ETI). We demonstrate that scintillations are very likely to allow initial detections of narrowband signals from distant sources (> 100 pc), while making redetections improbable. We consider three models in order to assess the non-repeating

M. Cassidy, L. F. Fortson, J. W. Fowler, R. A. Ong

The lateral distribution of Cherenkov light at ground level records important information on the development of the cosmic ray air shower which produces it. We have constructed an array of 144 non-imaging Cherenkov detectors at the CASA-MIA experiment site in Dugway, Utah. The various arrays can sample simultaneously the lateral distributions of electrons, m

David Burstein, Ralf Bender, Sandra Faber, Richard Nolthenius

The kappa-space three-dimensional parameter system was originally defined for the physical properties of dynamically hot galaxies. Here we define self-consistent kappa-parameters for disk galaxies, galaxy groups and clusters, and globular clusters and project an integrated view of the major classes of self-gravitating, equilibrium stellar systems in the univ

E. V. Gotthelf, R. Petre, U. Hwang

We consider the nature of the elusive neutron star candidate 1E~161348-5055 using X-ray observations obtained with the ASCA Observatory. The compact X-ray source is centered on the shell-type Galactic supernova remnant RCW103 and has been interpreted as a cooling neutron star associated with the remnant. The X-ray spectrum of the remnant shell can be charact

R. B. C. Henry, K. B. Kwitter, J. Buell

A project which aims to understand the abundance patterns of He, C, N, O, Ne, S, and Ar for a small sample of planetary nebulae is described. Abundance ratios of O/H, C/O, and N/O especially show a broad range relative to their solar values, and AGB stellar evolution models used to interpret the patterns indicate that reasonable ranges in progenitor mass and

The ISO-HDF Consortium, :, Bob Mann

We discuss the identification of sources detected by ISO at 6.7 and 15 micron in the Hubble Deep Field (HDF) region. We conservatively associate ISO sources with objects in existing optical and near-infrared HDF catalogues using the likelihood ratio method, confirming these results (and, in one case, clarifying them) with independent visual searches. We find

E. E. Falco, C. S. Kochanek, J. M. Munoz

We are conducting a redshift survey of 177 flat-spectrum radio sources in 3 samples covering the 5GHz flux ranges 50-100, 100-200 and 200-250 mJy. So far, we have measured 124 redshifts with completenesses of 80%, 68% and 58% for the bright, intermediate, and faint flux ranges. Using the newly determined redshift distribution we can derive cosmological limit

J Bordes, HM Chan, J Faridani, J Pfaudler

The suggestion is made that air showers with energies beyond the Greisen-Zatsepin-Kuz'min spectral cut-off may have primary vertices some 6 km lower in height than those of proton initiated showers with energies below the GZK cut-off. This estimate is based on the assumption that post-GZK showers are due to neutrinos having acquired strong interactions f

The ISO-HDF Consortium, :, Michael Rowan-Robinson

We have modelled the spectral energy distributions of the 13 HDF galaxies reliably detected by ISO. For 2 galaxies the emission detected by ISO is consistent with being starlight or the infrared 'cirrus' in the galaxies. For the remaining 11 galaxies there is a clear mid-infrared excess, which we interpret as emission from dust associated with a stro

The ISO-HDF Consortium, :, Seb Oliver

We present source counts at 6.7 micron and 15 micron from our maps of the Hubble Deep Field region, reaching 38.6 microJy at 6.7 micron and 255 microJy at 15 micron. These are the first ever extra-galactic number counts to be presented at 6.7 micron and are 3 decades fainter than IRAS at 12 micron. Both source counts and a P(D) analysis suggest we have reach

The ISO-HDF Consortium, :, Pippa Goldschmidt

We present positions and fluxes of point sources found in the Infrared Space Observatory (ISO) images of the Hubble Deep Field (HDF) at 6.7 and 15 micron. We have constructed algorithmically selected ``complete'' flux-limited samples of 19 sources in the 15 micron image, and 7 sources in the 6.7 micron image. The typical flux limit at 15 micron is 0.

The ISO-HDF Consortium, :, Steve Serjeant

We present deep imaging at 6.7 micron and 15 micron from the CAM instrument on the Infrared Space Observatory (ISO), centred on the Hubble Deep Field (HDF). These are the deepest integrations published to date at these wavelengths in any region of sky. We discuss the observation strategy and the data reduction. The observed source density appears to approach

M. J. Hudson, J. R. Lucey, R. J. Smith, J. Steel

We have measured the mean peculiar motions of 103 early-type galaxies in 7 clusters in the Perseus-Pisces (PP) ridge or PP background, and a further 249 such galaxies in 9 calibrating clusters from the literature, using the inverse Fundamental Plane relation. This relation is found to have a distance error of 20% per galaxy. None of the 6 clusters in the PP

R. J. Smith, J. R. Lucey, M. J. Hudson, J. Steel

We present new spectroscopic and photometric data for 137 early-type galaxies in nine clusters, and for a set of nearby standard galaxies. The clusters studied are Perseus (A0426), Pisces, A0262, A0347, J8, HMS0122+3305, 7S21, A2199 and A2634. Our spectroscopic data comprise radial velocities (cz), central velocity dispersions (sigma) and magnesium line stre

G. A. Medina Tanco, E. M. de Gouveia Dal Pino

Using the cosmic ray (CR) data available in the energy interval $(10 - 2 \times 10^{7})$ GeV/particle, we have calculated the profile of the primary $γ$-ray spectrum produced by the interaction of these CR with thermal nuclei of the ISM. Normalized to the EGRET measurements, this allows an estimate of the galactic diffuse $γ$-ray background due to intermedia

Glenn D. Starkman, Craig J Copi

Natural (such as lunar) occultations have long been used to study sources on small angular scales, while coronographs have been used to study high contrast sources. We propose launching the Improved Resolution and Image Selection (IRIS) Satellite, a large steerable occulting satellite. IRIS will have several advantages over standard occulting bodies. IRIS bl

Jesper Sommer-Larsen, Henrik Vedel, Uffe Hellsten

Effects of gravitational softening on the global structure of self-gravitating disks in centrifugal equillibrium are examined in relation to hydrodynamical/gravitational simulations. The one-parameter spline softening proposed by Hernquist & Katz is used. It is found that if the characteristic size of a disk, r, is comparable or less than the gravitational s