January 1998 arXiv papers — page 8

D. R. Goncalves, V. Jatenco-Pereira, R. Opher

It was shown by dos Santos et al. the importance of Alfvén waves to explain the winds of Wolf-Rayet stars. We investigate here the possible importance of Alfvén waves in the creation of inhomogeneities in the winds of early-type stars. The observed infrared emission (at the base of the wind) of early-type stars is often larger than expected. The clumping exp

Pieter G. van Dokkum, Marijn Franx, Daniel D. Kelson, Garth D. Illingworth

We use a large mosaic of HST WFPC2 images to measure the colors and morphologies of 194 spectroscopically confirmed members of the rich galaxy cluster CL1358+62 at z=0.33. We study the color-magnitude (CM) relation as a function of radius in the cluster. The intrinsic scatter in the restframe B-V CM relation of the elliptical galaxies is very small: ~0.022 m

G. L. Hoffman, N. Y. Lu, E. E. Salpeter, B. M. Connell

MCG+00-32-16 is the galaxy closest in position-velocity space to the lowest redshift Ly$α$ absorber along the line-of-sight to the quasar 3C 273. Its projected separation is 204 (d/19 Mpc) kpc, where d is the distance from the Milky Way to the galaxy, and the redshift difference is only 94 km/s; HI 1225+01 is slightly closer in projected separation to the ab

H. Heiselberg, M. Hjorth-Jensen

As rotating neutron stars slow down, the pressure and the density in the core region increase due to the decreasing centrifugal forces and phase transitions may occur in the center. We extract the analytic behavior near the critical angular velocity $Ω_0$, where the phase transitions occur in the center of a neutron star, and calculate the moment of inertia,

L. V. E. Koopmans, A. G. de Bruyn, N. Jackson

We present new observations of the gravitational lens (GL) system B1600+434, strongly suggesting that the lens is an edge-on spiral galaxy. These observations are used to constrain the mass model of the system, in particular the oblateness and velocity dispersion of the dark matter halo around the lensing galaxy. From an analytical model we find a lower limi

G. Fiorentini, B. Ricci

We summarize the results of solar neutrino experiments and update a solar model independent analysis of solar neutrino data. We discuss the implications of helioseismology on solar models and predicted solar neutrino fluxes. Finally , we discuss the potential of new experiments for detecting specific signatures of the proposed solutions to the solar neutrino

J. A. Peacock, R. Jimenez, J. S. Dunlop, I. Waddington

We have discovered a population of extremely red galaxies at $z\simeq 1.5$ which have apparent stellar ages of $\gs 3$ Gyr, based on detailed spectroscopy in the rest-frame ultraviolet. In order for galaxies to have existed at the high collapse redshifts indicated by these ages, there must be a minimum level of power in the density fluctuation spectrum on ga

S. Bonazzola, E. Gourgoulhon

Both observational and theoretical rates of binary neutron star coalescence give low prospects for detection of a single event by the initial LIGO/VIRGO interferometers. However, by utilizing at the best all the a priori information on the expected signal, a positive detection can be achieved. This relies on the hypothesis that $γ$-ray bursts are the electro

Christian Maes, Wolfgang Spitzer

We consider quasi-free quantum systems and we derive the Euler equation using the so-called hydrodynamic limit. We use Wigner's well-known distribution function and discuss an extension to band distribution functions for particles in a periodic potential. We investigate the Bosonic system of hard rods and calculate fluctuations of the density. Keywords:

A. Hanany, A. Zaffaroni

We consider a general brane construction for realizing chiral four-dimensional gauge theories. The advantage of the construction is the simplicity and the possibility of realizing a large class of models existing in the literature. We start the study of these models by determining the matter content and the superpotential which naturally arise in the brane c

G. Akemann, P. H. Damgaard

Exact results from random matrix theory are used to systematically analyse the relationship between microscopic Dirac spectra and finite-volume partition functions. Results are presented for the unitary ensemble, and the chiral analogs of the three classical matrix ensembles: unitary, orthogonal and symplectic, all of which describe universality classes of $

A. N. Kamal

CP-violating signals in weak $ Ξ\to πΛ$ decay require the knowledge of $πΛ$ $S$- and $P$-wave scattering phases at ${m}_Ξ$ center-of-mass energy. We have calculated these phases in baryon chiral perturbation theory with the ground-state $Σ$ in $s$ and $u$ channels and ${3 \over 2}^{+}$ $Σ(1385)$ in the $u$ channel. We do not treat the baryons as heavy. We fi

David B. Kaplan, Martin J. Savage, Mark B. Wise

We introduce a new and well defined power counting for the effective field theory describing nucleon-nucleon interactions. Because of the large NN scattering lengths it differs from other applications of chiral perturbation theory and is facilitated by introducing an unusual subtraction scheme and renormalization group analysis. Calculation to subleading ord

Goetz S. Uhrig

The validity of the adiabatic approach to spin-Peierls transitions is assessed. An alternative approach is developed which maps the initial magneto-elastic problem to an effective magnetic problem only. Thus the equivalence of magneto-elastic solitons and magnetic spinons is shown. No soft phonon is required for the transition. Temperature dependent coupling

Ran Sivron

Compact plasmas, that exist near black-hole candidates and in gamma ray burst sources, commonly exhibit self-organized non-linear behavior. A model that simulates the non-linear behavior of compact radiative plasmas is constructed directly from the observed luminosity and variability. The simulation shows that such plasmas self organize, and that the degree

E. V. Ivashkevich

The model of dense lattice polymers is studied as an example of non-unitary Conformal Field Theory (CFT) with $c=-2$. ``Antisymmetric'' correlation functions of the model are proved to be given by the generalized Kirchhoff theorem. Continuous limit of the model is described by the free complex Grassmann field with null vacuum vector. The fundamental

G. Hildebrand, E. Arrigoni, C. Gröber, W. Hanke

We analyze single-particle electronic and two-particle magnetic properties of the Hubbard model in the underdoped and optimally-doped regime of \YBCO by means of a modified version of the fluctuation-exchange approximation, which only includes particle-hole fluctuations. Comparison of our results with Quantum-Monte Carlo (QMC) calculations at relatively high

C. T. Sachrajda

In these four lectures I review the theory and phenomenology of weak decays of quarks, and their rôle in the determination of the parameters of the Standard Model of particle physics, in testing subtle features of the theory and in searching for signatures of new physics. Attempts to understand CP-violation in current and future experiments is discussed.

P. Ao

In this comment, I point out a number of approximated derivations for the effective equation of motion, now been applied to d-wave superconductors by Kopnin and Volovik are invalid. The major error in those approximated derivations is the inappropriate use of the relaxation time approximation in force-force correlation functions, or in force balance equation

M. Kirchbach

The flavor SU(3)_f group symmetry of QCD is systematically considered as the heavy c quark limit of SU(4)_f. Within that scheme we argue that the U(1)_A anomaly prevents Gell-Mann's choice for the realization of the su(4)_f (and thereby the su(3)_f) algebra for the particular case of the neutral axial currents. Rather, Weyl's choice for the SU(4)_f g

D. Brecher, M. J. Perry

We attempt to settle the issue as to what is the correct non-abelian generalisation of the Born-Infeld action, via a consideration of the two-loop $β$--function for the non-abelian background gauge field in open string theory. An analysis of the bosonic theory alone shows the recent proposal of Tseytlin's to be somewhat lacking. For the superstring, howe

Peter Hasenfratz, Victor Laliena, Ferenc Niedermayer

The fixed point Dirac operator on the lattice has exact chiral zero modes on topologically non-trivial gauge field configurations independently whether these configurations are smooth, or coarse. The relation $n_L-n_R = Q^{FP}$, where $n_L$ $(n_R)$ is the number of left (right)-handed zero modes and $Q^{FP}$ is the fixed point topological charge holds not on

A. Borowiec, M. Ferraris, M. Francaviglia

This paper analyses the Noether symmetries and the corresponding conservation laws for Chern-Simons Lagrangians in dimension $d=3$. In particular, we find an expression for the superpotential of Chern-Simons gravity. As a by-product the general discussion of superpotentials for 3rd order natural and quasi-natural theories is also given.

Y. Kanazawa, Yuji Koike, N. Nishiyama

We present a leading order (LO) estimate for the longitidinal-transverse spin asymmetry (A_{LT}) in the nucleon-nucleon polarized Drell-Yan process at RHIC and HERA-$\vec{N}$ energies in comparison with A_{LL} and A_{TT}. A_{LT} receives contribution from g_1, the transversity ditribution h_1, and the twist-3 distributions g_T and h_L. For the twist-3 contri

Isaac L. Chuang, Lieven M. K. Vandersypen, Xinlan Zhou, Debbie W. Leung

Nuclear magnetic resonance techniques are used to realize a quantum algorithm experimentally. The algorithm allows a simple NMR quantum computer to determine global properties of an unknown function requiring fewer function ``calls'' than is possible using a classical computer.

Inyong Cho, Jemal Guven

A thin wall approximation is exploited to describe a global monopole coupled to gravity. The core is modelled by de Sitter space; its boundary by a thin wall with a constant energy density; its exterior by the asymptotic Schwarzschild solution with negative gravitational mass $M$ and solid angle deficit, $ΔΩ/4π= 8πGη^2$, where $η$ is the symmetry breaking sc

Sergei V. Shabanov

A system with anholonomic constraints where the trajectories of physical degrees of freedom are autoparallels on a manifold equipped with a general Cartan connection is discussed. A variational principle for the autoparallel trajectories is derived from the d'Alambert-Lagrange principle for anholonomic constrained systems. A geometrical (coordinate-indep

Bin Zhang, Miklos Gyulassy, Yang Pang

We develop two further numerical tests of parton cascade models: the ideal gas equation of state and the collision frequency tests. The equation of state test checks the initial momentum distribution generator and free expansion dynamics in periodic inhomogeneous geometries. The collision rate test is sensitive to spatial inhomogeneities and the collision al

Sandra S. Padula, Cristiane G. Roldao

Adopting a procedure previously proposed to quantitatively study two-dimensional pion interferometry, an equivalent 2-D chi^2 analysis was performed to test the resolving power of that method when applied to less favorable conditions, i.e., if no significant contribution from long lived resonances is expected, as in kaon interferometry. For that purpose, use

U. Meyer, Amand Faessler, S. B. Khadkikar

The axial Rotation Vibration Model is here extended to describe also triaxial equilibrium shapes with beta and gamma vibrations allowing for the interaction between vibrations and rotations. This Triaxial Rotation Vibration Model (TRVM) is applied to Xe and Ba isotopes with mass numbers between 120 and 130. This area has recently been pointed out to be the O

D. V. Fedorov, A. Cobis, A. S. Jensen

We try to explain the differences in the 6He dipole strength function in refs. [1] and [2]. We perform the full basis calculation of the strength function with the same renormalized interaction as in [1] and show that the size of the basis, needed for converged calculations of the 6He continuum spectrum, is much larger than that for the discrete spectrum. Th

P. Bozek, P. Danielewicz, K. Gudima, M. Ploszajczak

Possibility of observing the Mott momentum in the distribution of the deuterons produced in the process $p + n \to d + γ$, in the first stage of a nuclear reaction is presented. The correlation of a hard photon with a deuteron allows to select those deuterons produced at the beginning of a reaction.

U. Meyer, A. J. Buchmann, Amand Faessler

We calculate photoexcitation amplitudes for several nucleon and delta resonances. We use a chiral quark model including two-body exchange currents. The two-body currents give important contributions. For the delta (1232) and the D13 (1520) we observe that the individual exchange current contributions considerably cancel each other while in the case of the Ro

Rade T. Živaljević

We show that the well known {\em homotopy complementation formula} of Björner and Walker admits several closely related generalizations on different classes of topological posets (lattices). The utility of this technique is demonstrated on some classes of topological posets including the Grassmannian and configuration posets, $\widetilde{\mathbf G}_n(R)$ and

Peter W. Michor, Alexandre M. Vinogradov

With the help of the multigraded Nijenhuis-- Richardson bracket and the multigraded Gerstenhaber bracket from [7] for every $n\ge 2$ we define $n$-ary associative algebras and their modules and also $n$-ary Lie algebras and their modules, and we give the relevant formulas for Hochschild and Chevalley cohomogy.

Hélène Esnault

This is a survey on the topic explained in the title, for the proceedings on the K-theory 1997 summer institute in Seattle.

Jintai Ding

We use the idea of partial Gauss decomposition to study structures related to $U_q(\widehat{\frak{gl}(n-1)})$ inside $U_q(\widehat{\frak{gl}(n)}) $. This gives a description of $U_q(\widehat{\frak{gl}(n)})$ as an extension of $U_q(\widehat{\frak{gl}(n-1)})$ with Zamolodchikov algebras, We explain the connection of this new realization with form factors.

Jintai Ding, Boris Feigin

Starting from bosonization, we study the operator that commute or commute up-to a total difference with of any quantized screen operator of a free field. We show that if there exists a operator in the form of a sum of two vertex operators which has the simplest correlation functions with the quantized screen operator, namely a function with one pole and one

L. C. Kwek, C. H. Oh

It is well-known that the Macfarlane-Biedenharn $q$-oscillator and its generalization has no Hopf structure, whereas the Hong Yan $q$-oscillator can be endowed with a Hopf structure. In this letter, we demonstrate that it is possible to construct a general $q$-oscillator algebra which includes the Macfarlane-Biedenharn oscillator algebra and the Hong Yan osc

Stefan Schwede, Brooke E. Shipley

We construct model category structures for monoids and modules in symmetric monoidal model categories which satisfy an extra axiom, the monoidal axiom, with applications to symmetric spectra and $Γ$-spaces.

Bergfinnur Durhuus, Thordur Jonsson

Using the observation that configurations of N polymers with hard core interactions on a closed random surface correspond to random surfaces with N boundary components we calculate the free energy of a gas of polymers interacting with fully quantized two-dimensional gravity. We derive the equation of state for the polymer gas and find that all the virial coe

M Bordag, J Lindig

The first radiative correction to the Casimir energy of a perfectly conducting spherical shell is calculated. The calculation is performed in the framework of covariant perturbation theory with the boundary conditions implemented as constraints. The formalism is briefly reviewed and its use is explained by deriving the known results for two parallel planes.

E. Gava, J. F. Morales, K. S. Narain, G. Thompson

We study the infra-red limit of the O(N) gauge theory that describes the low energy modes of a system of $N$ type I D-strings and provide some support to the conjecture that, in this limit, the theory flows to an orbifold conformal theory. We compute the elliptic genus of the orbifold theory and argue that its longest string sector describes the bound states

S. Catani, B. R. Webber

We give perturbative predictions for the distribution of the $C$-Parameter event shape variable in $e^+e^-$ annihilation, including resummation of large logarithms in the two-jet (small-$C$) region, matched to next-to-leading order results. We also estimate the leading non-perturbative power correction and make a preliminary comparison with experimental data

M. E. Gomez, K. Tamvakis

We consider a class of supersymmetric SU(3)\times SU(2)\times U(1) multihiggs models in which R-parity is violated through bilinear Higgs-lepton interactions. The required, due to R-parity violation, higgs-lepton rotations introduce an alternative way to generate the phenomenologically desirable fermion mass matrix structures independently of the equality of

M. Schvellinger, N. N. Scoccola

Using the recently proposed approximation for multiskyrmion fields based on rational maps we study the masses and baryonic radii of some strange multibaryons within the bound state soliton model. We find the tetralambda binding to be stronger than previously expected. In addition, the model predicts the existence of a ``heptalambda'' which is stable

Bodo Lampe

The complete set of matrix elements for all polarization configurations in top quark decays is presented including higher order QCD corrections. The analysis is done in the framework of the helicity formalism. The results can be used in a variety of circumstances, e.g. in the experimental analysis of top quark production and decay at Tevatron, LHC and NLC. R

B. L. Ioffe, A. G. Oganesian

The part of the proton spin $\Sigma$ carried by $u, d, s$ quarks is calculated in the framework of the QCD sum rules in the external fields. The operators up to dimension 9 are accounted. An important contribution comes from the operator of dimension 3, which in the limit of massless $u, d, s$ quarks is equal to the derivative of QCD topological susceptibili

A. Peshier, B. Kämpfer, O. P. Pavlenko, G. Soff

Relying on the Luttinger-Ward theorem we derive a thermodynamically selfconsistent and scale independent approximation of the thermodynamic potential for the scalar $ϕ^4$ theory in the tadpole approximation. The resulting thermodynamic potential as a function of the temperature is similar to the one of the recently proposed screened perturbation theory.

I. S. Sogami, K. Nishida, H. Tanaka, T. Shinohara

To extract sum rules of CKM matrix elements, eigenvalue problems for quasi-democratic mass matrices are solved in the first order perturbation approximation with respect to small deviations from the democratic limit. Mass spectra of up and down quark sectors and the CKM matrix are shown to have clear and distinctive hierarchical structures. Numerical analysi

G. Lazarides

A supersymmetric model based on a left-right symmetric gauge group is proposed where hybrid inflation, baryogenesis and neutrino oscillations are linked.This scheme, supplemented by a familiar ansatz for the neutrino Dirac masses and mixing of the two heaviest families and with the MSW resolution of the solar neutrino puzzle, implies that $m_{ν_τ}$ lies betw

G. Mannocchi, L. Periale, P. Picchi, F. Pietropaolo

We point out that the measurement of the $L/E$ distribution of atmospheric neutrino events with sufficient resolution in order to observe the characteristic modulations of neutrino oscillations would provide a unique way to test the $\numunux$ oscillations nature of the atmospheric neutrino anomaly in the parameter range $5\times 10^{-4} < Δm^2 < 2\times 10^

Su Houng Lee

In the introduction, we will discuss the symmetries of QCD, its breaking in the physical vacuum and its restoration at finite temperature and/or density. Then we will discuss what exact relations can be made between chiral symmetry restoration and the imaginary part of the vector vector correlation function, which is directly related to the dilepton spectrum

Kuang-Ta Chao, Cong-Feng Qiao, Feng Yuan

We report the recent progress in the studies of D-wave heavy quarkonia production from gluon fragmentation at the Tevatron and in Z^0 decays, and the D-wave charmonia production in B decays. We show that the color-octet contributions are of crucial importance to the production of D-wave quarkonia. Signals, as strong as that for J/ψand ψ^\prime, should be see

W. de Boer, R. Ehret, A. V. Gladyshev, D. I. Kazakov

The new precise LEP measurements of alphas and the electroweak mixing angle as well as the new LEP II mass limits for supersymmetric particles and new calculations for the radiative (penguin) decay of the b-quark into sgamma allow a further restriction in the parameter space of the Constrained Minimal Supersymmetric Standard Model (CMSSM).

W. Bietenholz, U. -J. Wiese

We show how to include a chemical potential μin perfect lattice actions. It turns out that the standard procedure of multiplying the quark fields Ψ, \barΨat Euclidean time t by \exp(\pm μt), respectively, is perfect. As an example, the case of free fermions with chemical potential is worked out explicitly. Even after truncation, cut-off effects in the pressu

J. B. Kogut, J. -F. Lagae, D. K. Sinclair

We compute the screening correlators in the sigma and eta&#39; flavor singlet channels in finite temperature QCD with 2 light quark flavors. Together with the correlators in the pi and delta channels, these are used to discuss several issues related to symmetry restoration and the nature of the QCD phase transition. Our calculations span a range of temperatu

J. B. Kogut, J. -F. Lagae, D. K. Sinclair

We have studied lattice QCD with an additional, irrelevant 4-fermion interaction having a U(1)xU(1) chiral symmetry, at finite temperatures. Adding this 4-fermion term allowed us to work at zero quark mass, which would have otherwise been impossible. The theory with 2 massless staggered quark flavours appears to have a first order finite temperature phase tr

Eckehard W. Mielke, Franz E. Schunck

Boson stars are descendants of the so-called geons of Wheeler, except that they are built from scalar particles instead of electromagnetic fields. If scalar fields exist in nature, such localized configurations kept together by their self-generated gravitational field can form within Einstein&#39;s general relativity. In the case of complex scalar fields, an

M. Panahi, M. Mehrafarin

H. Akbar-Zadeh has recently proposed (J Geom Phys 17 (1995) 342) a new geometric formulation of Einstein-Maxwell system with source in terms of what are called &#34;Generalized Einstein manifolds&#34;. We show that, contrary to the claim, Maxwell equations have not been derived in this formulation and that, the assumed equations can be identified only as sou

Frank Antonsen

We obtain an hybrid expression for the heat-kernel, and from that the density of the free energy, for a minimally coupled scalar field in a Schwarzschild geometry at finite temperature. This gives us the zero-point energy density as a function of the distance from the massive object generating the gravitational field. The contribution to the zero-point energ

A. Bill, S. A. Wolf, Yu. N. Ovchinnikov, V. Z. Kresin

The ordering trend of magnetic impurities at low temperature results in the frustration of the pair-breaking effect and induces a ``recovery&#39;&#39; of superconducting properties. We show that this effect manifests itself in the deviation of the Josephson current amplitude from the values obtained within the Ambegaokar-Baratoff and the Abrikosov-Gor&#39;ko

Y. Naveh, D. V. Averin, K. K. Likharev

A theory of non-equilibrium (``shot&#39;&#39;) noise and high frequency conductance in diffusive mesoscopic conductors with screening is presented. Detailed results are obtained for two simple geometries, for both large and short electron-electron scattering length $l_{ee}$, at frequencies of the order of the inverse Thouless time $1/τ_T$. The conductance an

G. D. Mahan, J. O. Sofo, M. Bartkowiak

A new method of refrigeration is proposed. Cooling is obtained by thermionic emission of electrons over periodic barriers in a multilayer geometry. These could be either Schottky barriers between metals and semiconductors or else barriers in a semiconductor superlattice. The same device is an efficient power generator. A complete theory is provided.

A. Bill, V. Z. Kresin, S. A. Wolf

We show that various factors can lead to an isotopic dependence of the penetration depth $δ$. Non-adiabaticity (Jahn-Teller crossing) leads to the isotope effect of the charge carrier concentration $n$ and, consequently, of $δ$ in doped superconductors such as the cuprates. A general equation relating the isotope coefficients of $T_c$ and of $δ$ is presented

I. Tsatskis, E. K. H. Salje

The equilibrium short-range order (SRO) in Cu-Pd alloys is studied theoretically. The evolution of the Fermi surface-related splitting of the (110) diffuse intensity peak with changing temperature is examined. The results are compared with experimental observations for electron-irradiated samples in a steady state, for which the temperature dependence of the

E. V. Ivashkevich, V. B. Priezzhev

This article is based on a talk given by one of us (EVI) at the conference ``StatPhys-Taipei-1997&#39;&#39;. It overviews the exact results in the theory of the sandpile model and discusses shortly yet unsolved problem of calculation of avalanche distribution exponents. The key ingredients include the analogy with the critical reaction-diffusion system, the

L. B. Ioffe, A. J. Millis

We present a Boltzmann equation analysis of the transport properties of a model of electrons with a lifetime which is short everywhere except near the Brillouin zone diagonals. The anomalous lifetime is directly implied by photoemission and c-axis transport data. We find quantitative agreement between calculations and ac and dc longitudinal and Hall resistiv

John P. Hughes, Mark Birkinshaw

A value of the Hubble constant has been determined from a comparison of the X-ray properties and Sunyaev-Zel&#39;dovich effect of the distant rich cluster of galaxies CL0016+16. The cluster, as imaged by the ROSAT PSPC, is significantly elliptical and we present the techniques we have developed to include this in our analysis. Assuming a smooth, isothermal g

Frank J. Masci

A majority of quasar surveys have been based on criteria which assume strong blue continua or a UV-excess. Any amount of dust along the line-of-sight is expected to drastically extinguish the optical/UV flux leading to a selection bias. Radio surveys however should suffer no bias against extinction by dust. Recently, a large complete sample of radio-selected

Holland Ford, Zlatan Tsvetanov

Three sets of HST+COSTAR FOS and FOC observations provide strong evidence that the nuclear disk in M87 is in Keplerian rotation around a black hole with a mass of (2 - 3)x10^9 M_sol. A deep (6 orbits), high resolution H-alpha+[NII] PC2 HST image shows a trailing, three arm spiral superposed on the underlying nuclear disk. Several of the extended filaments ap

M. J. Hardcastle, P. Alexander, G. G. Pooley, J. M. Riley

In previous papers we have discussed high-resolution observations of a large sample of powerful radio galaxies with z<0.3. Jets are detected in up to 80 per cent of the sample, and radio cores in nearly all the objects; in addition, we are able to resolve the hot spots in most sources. In this paper we present measurements of the radio properties of these co

K. M. Xilouris, M. Kramer, A. Jessner, A. von Hoensbroech

We have made polarimetric monitoring observations of millisecond pulsars visible from the northern hemisphere at 1410 MHz. Their emission properties are compared with those of normal pulsars. Although we demonstrated in paper I that millisecond pulsars exhibit the same flux density spectra and similar profile complexity, our results presented here suggest th

M. Kramer, K. M. Xilouris, D. Lorimer, O. Doroshenko

We have monitored a large sample of millisecond pulsars using the 100-m Effelsberg radio telescope in order to compare their radio emission properties to the slowly rotating population. With some notable exceptions, our findings suggest that the two groups of objects share many common properties. A comparison of the spectral indices between samples of normal

A. K. Grant

We review some recent theoretical progress in the understanding of weak radiative B meson decay, and discuss the implications of present and improved measurements of b -> s gamma for supersymmetric models.

K. Zioutas, C. E. Aalseth, D. Abriola, F. T. Avignone

The 8.4 Tesla, 10 m long transverse magnetic field of a twin aperture LHC bending magnet can be utilized as a macroscopic coherent solar axion-to-photon converter. Numerical calculations show that the integrated time of alignment with the Sun would be 33 days per year with the magnet on a tracking table capable of $\pm 5^o$ in the vertical direction and $\pm

Shahar Hod, Tsvi Piran

We study the nonlinear gravitational collapse of a charged massless scalar-field. We confirm the existence of oscillatory inverse power-law tails along future timelike infinity, future null infinity and along the future outer-horizon. The nonlinear dumping exponents are in excellent agreement with the analytically predicted ones. Our results prove the analyt

V. Periwal, R. von Unge

Higher derivative terms are computed in the one-loop effective action governing the interactions of D3-branes, in two ways: (1) in a formalism with N=2 supersymmetry preserved off-shell, and (2) in the standard background field formalism, with only on-shell supersymmetry. It is shown that these calculations only agree using tree-level equations of motion. Th

Shahar Hod, Tsvi Piran

We study analytically the initial value problem for a self-interacting (massive) scalar-field on a Reissner-Nordström spacetime. Following the no-hair theorem we examine the dynamical physical mechanism by which the self-interacting (SI) hair decays. We show that the intermediate asymptotic behaviour of SI perturbations is dominated by an oscillatory inverse

K. S. Virbhadra, D. Narasimha, S. M. Chitre

A static and circularly symmetric lens characterized by mass and scalar charge parameters is constructed. For the small values of the scalar charge to the mass ratio, the gravitational lensing is qualitatively similar to the case of the Schwarzschild lens; however, for large values of this ratio the lensing characteristics are significantly different. The ma

Chong-Sheng Li, Shou-Hua Zhu, Cong-Feng Qiao

Neutral Higgs boson radiative decays of the form h_0, H, A \to f\bar{f}γ, in the light fermion limit $m_f->0, are calculated in the two Higgs doublet model at one-loop level. Comparisons with the calculation within the standard model are given, which indicates that these two models are distinguishable in the decay mode fermion-antifermion -photon. Our result

Wilfried Schmid, Kari Vilonen

In this paper we prove two formulas for the characters of representations of reductive groups. Both express the character of a representation in terms of the same geometric data attached to it. When specialized to the case of a compact Lie group, one of them reduces to Kirillov&#39;s character formula in the compact case, and the other, to an application of

Tianjun Li

Keeping N=1 supersymmetry in 4-dimension and in the leading order, we disuss the various orbifold compactifications of M-theory suggested by Horava and Witten on $T^6/Z_3$, $T^6/Z_6$, $T^6/Z_{12}$, and the compactification by keeping singlets under $SU(2)\times U(1)$ symmetry, then the compactification on $S^1/Z_2$. We also discuss the next to leading order

W. Kummer, H. Liebl, D. V. Vassilevich

The trace anomaly for nonminimally coupled scalars in spherically reduced gravity obtained by Bousso and Hawking (hep-th/9705236) is incorrect. We explain the reasons for the deviations from our correct (published) result which is supported by several other recent papers.

Feng Yuan, Kuang-Ta Chao

Presented here is a study of the large p_T J/psi production in hard diffractive process by the pomeron exchange at the Fermilab Tevatron. We find that this process (p\bar p \to p+J/psi+X) can be used to probe the gluon content of the pomeron and to measure the gluon fraction of the pomeron. And the diffractive direct J/psi production can also provide another

A. Mastellone, G. Falci, Rosario Fazio

By means of the Lanczos method we analyze superconducting correlations in ultrasmall grains at fixed particle number. We compute the ground state properties and the excitation gap of the pairing Hamiltonian as a function of the level spacing $δ$. Both quantities turn out to be parity dependent and universal functions of the ratio $δ/Δ$ ($Δ$ is the BCS gap).

Boaz Giron, Baruch Meerson, Pavel V. Sasorov

We support and generalize a weak selection rule predicted recently for the self-similar asymptotics of the distribution function (DF) in the zero-volume-fraction limit of Ostwald ripening (OR). An asymptotic perturbation theory is developed that, when combined with an exact invariance property of the system, yields the selection rule, predicts a power-law co

Garret Cotter, Toby Haynes

We present the first results of a deep imaging programme to identify the system responsible for the Cosmic Microwave Background decrement in the field towards the z = 3.8 quasar pair PC1643+4631 A&B. Using the prime focus camera at the William Herschel Telescope we have carried out deep multicolour optical imaging to search for candidate cluster galaxies at

M. Akiyama, K. Ohta, T. Yamada, M. Eracleous

We report the optical identification of the hardest X-ray source (AX J131501+3141) detected in an unbiased wide-area survey in the 0.5--10 keV band, the ASCA Large Sky Survey. The X-ray spectrum of the source is very hard and is well reproduced by a power-law component (Gamma = 1.5^+0.7_-0.6) with N_H = 6^+4_-2 *10^22 cm^-2 (Sakano et al. 1998). We have foun

U. Zuelicke, A. H. MacDonald, M. D. Johnson

When the bulk filling factor is equal to 1 - 1/m with m odd, at least one counterpropagating chiral collective mode occurs simultaneously with magnetoplasmons at the edge of fractional-quantum-Hall samples. Initial experimental searches for an additional mode were unsuccessful. In this paper, we address conditions under which its observation should be expect

N. C. Mukhopadhyay, M. J. Ramsey-Musolf, S. J Pollock, J. Liu

We consider prospects for studying the parity-violating (PV) electroweak excitation of the Δ(1232) resonance with polarized electron scattering. Given present knowledge of Standard Model parameters, such PV experiments could allow a determination of the N -> Δelectroweak helicity amplitudes. We discuss the experimental feasibility and theoretical interpretab

Alexey K. Mazur

For many biological applications of molecular dynamics (MD) the importance of good sampling in conformational space makes it necessary to eliminate the fastest motions from the system in order to increase the time step. An accurate knowledge of these motions is a necessary prerequisite for such efforts. It is known that harmonic vibrations of bond lengths an

Guang-jiong Ni

Some conceptual problems in physics are discussed. Do we need a change in the concept of matter structure? Why the ``$i=\sqrt{-1}$&#39;&#39; is introduced to quantum mechanics (QM) essentially? What is the relation between QM and special relativity (SR)? Could we modify the stationary Schr$\ddot{\rm o}$dinger equation in conformity with SR? How can a particl

J. Rayford Nix

On the basis of a nine-parameter expanding source model that includes special relativity, quantum statistics, resonance decays, and freeze-out on a realistic hypersurface in spacetime, we analyze in detail invariant pi+, pi-, K+, and K- one-particle multiplicity distributions and pi+ and K+ two-particle correlations in nearly central collisions of Si + Au at

I. Stetcu

A quantum-mechanical calculation of the single-particle level (s.p.l.) density $g(ε)$ is carried on by using the connection with the single-particle Green&#39;s function. The relation between the imaginary part of Green&#39;s function and single-particle wave functions is used separately for the discrete and continuous states. Within the bound-states region

Caterina Consani

In the paper we show that for a normal-crossings degeneration $Z$ over the ring of integers of a local field with $X$ as generic fibre, the local monodromy operator and its powers determine invariant cocycle classes under the decomposition group in the cohomology of the product $X \times X$. More precisely, they also define algebraic cycles on the special fi

Jason Fulman

Solomon&#39;s descent algebra is used to define a family of signed measures M(W,x) for a finite Coxeter group W and non-zero x. The measures corresponding to W of types A and B are known to arise from the theory of card shuffling and to be related to the Poincare-Birkhoff-Witt theorem and splittings of Hochschild homology. Formulas for these measures are obt

Arthur Jaffe

In super-symmetric quantum theory, or in string theory, (including generalizations of these theories to underlying quantum spaces) we study a certain partition function Z(Q,A,g). Here Q denotes a supercharge, A denotes an observable with the property A^2 = I, and g denotes an element of a symmetry group of Q. The supercharge may depend on a parameter lambda,

Yuji Igarashi, Katsumi Itoh, Kiyoshi Kamimura, Rie Kuriki

We show that the super D-string action is canonically equivalent to the type IIB superstring action with a world-sheet gauge field. Canonical transformation to the type IIB theory with dynamical tension is also constructed to establish the SL(2,Z) covariance beyond the semi-classical approximations.

Chandrashekar Devchand, Olaf Lechtenfeld

We discuss the precise relation of the open N=2 string to a self-dual Yang-Mills (SDYM) system in 2+2 dimensions. In particular, we review the description of the string target space action in terms of SDYM in a ``picture hyperspace&#39;&#39; parametrised by the standard vectorial R^{2,2} coordinate together with a commuting spinor of SO(2,2). The component f