January 1997 arXiv papers — page 8

M. Bucher, J. D. Cohn

We calculate the spectrum of gravitational waves generated during inflation in open $(Ω_0<1)$ inflationary models. In such models an initial epoch of old inflation solves the horizon and flatness problems, and during this first epoch of inflation the quantum state of the graviton field rapidly approaches the Bunch-Davies vacuum. Then old inflation ends by th

Limin Lu, Wallace L. W. Sargent, Thomas A. Barlow

Proof of the existence of a significant population of normal disk galaxies at redshift z>2 would have profound implications for theories of structure formation and evolution. We present evidence based on Keck HIRES observations that the damped Lyman-alpha absorber at z=3.15 toward the quasar Q2233+1310 may well be such an example. Djorgovski et al have recen

Xinwei Kong, Finn Ravndal

The regularized total Casimir energy in spacetimes with boundaries is not in general equal to the integral of the regularized energy density. This paradoxical phenomenon is most transparently analyzed in the simple example of a massless scalar field in 1+1 dimensions confined to a line element of length $L$ and obeying Dirichlet boundary conditions.

V. N. Melekhin

It is shown that the point charge and magnetic moment of electron produce together such a field that total electromagnetic momentum has a component perpendicular to electron velocity. As a result classical electron models, having magnetic moment, move not along a straight line, if there is no external force, but along a spiral, the space period and radius of

Doug Bullock, Charles Frohman, Joanna Kania-Bartoszynska

For each skein module we describe a homology theory which, for any three manifold recovers the skein module at its zero level. The theory measures skein-like relations among skein relations, mimicking Hilbert&#39;s theory of syzygies. We work explicit examples for the homology groups corresponding to the Kauffman bracket. It is shown, in particular, that for

C. J. Benesh, A. C. Hayes, J. L. Friar

Shortcomings of a momentum-space treatment of strong absorption, as discussed in the previous Comment [nucl-th/9611025], are only of concern at low projectile energies, $γ$< 1.5. At intermediate and high energies, for which the quantum-mechanical equivalent-photon spectrum is intended, the quantum-mechanical cross sections are reduced relative to the semi-cl

F. A. Ivanyuk, H. Hofmann, V. V. Pashkevich, S. Yamaji

Previous computations of the potential landscape with the shapes parameterized in terms of Cassini ovaloids are extended to collective dynamics at finite excitations. Taking fission as the most demanding example of large scale collective motion, transport coefficients are evaluated along a fission path. We concentrate on those for average motion, namely stif

Y. Suzuki, J. Usukura, K. Varga

A new formulation is presented for a variational calculation of $N$-body systems on a correlated Gaussian basis with arbitrary angular momenta. The rotational motion of the system is described with a single spherical harmonic of the total angular momentum $L$, and thereby needs no explicit coupling of partial waves between particles. A simple generating func

William B. Johnson, Joram Lindenstrauss, Gideon Schechtman

Following results of Bourgain and Gorelik we show that the spaces $\ell_p$, $1<p<\infty$, as well as some related spaces have the following uniqueness property: If $X$ is a Banach space uniformly homeomorphic to one of these spaces then it is linearly isomorphic to the same space. We also prove that if a $C(K)$ space is uniformly homeomorphic to $c_0$, then

I. Ya. Arefeva, K. S. Viswanathan, A. I. Volovich, I. V. Volovich

We review an algebraic method of finding the composite p-brane solutions for a generic Lagrangian, in arbitrary spacetime dimension, describing an interaction of a graviton, a dilaton and one or two antisymmetric tensors. We set the Fock--De Donder harmonic gauge for the metric and the &#34;no-force&#34; condition for the matter fields. Then equations for th

I. J. R. Aitchison, N. E. Mavromatos, D. Mc Neill

By applying an inverse Landau-Khalatnikov transformation, connecting (resummed) Schwinger-Dyson treatments in non-local and Landau gauges of $QED_3$, we derive the infrared behaviour of the wave-function renormalization in the Landau gauge, and the associated critical exponents in the normal phase of the theory (no mass generation). The result agrees with th

M. T. Johnsson, I. J. R. Aitchison

The adiabatic evolution of two doubly-degenerate (Kramers) levels is considered. The general five-parameter Hamiltonian describing the system is obtained and shown to be equivalent to one used in the $Γ_8 \otimes(τ_2\oplusε)$ Jahn-Teller system. It is shown explicitly that the resulting SU(2) non-Abelian geometric vector potential is that of the (SO(5) symme

John D. Barrow, Kerstin E. Kunze

We present exact inhomogeneous and anisotropic cosmological solutions of low-energy string theory containing dilaton and axion fields. The spacetime metric possesses cylindrical symmetry. The solutions describe ever-expanding universes with an initial curvature singularity and contain known homogeneous solutions as subcases. The asymptotic form of the soluti

Stjepan Meljanac, Marijan Milekovic

We show that for every algebra of creation and annihilation operators with a Fock-like representation,one can define extended Haldane statistical parameters in a unique way. Specially for parastatistics, we calculate extended Haldane parameters and discuss the corresponding partition functions.

Adriano Di Giacomo, Manu Mathur

We investigate Georgi-Glashow model in terms of a set of explicitly SO(3) gauge invariant dynamical variables. In the new description a novel compact abelian gauge invariance emerges naturally. As a consequence magnetic monopoles occur as point like &#34;defects&#34; in space time. Their non-perturbative contribution to the partition function is explicitly i

Gary T. Horowitz, Haisong Yang

We examine the geometry near the event horizon of a family of black string solutions with traveling waves. It has previously been shown that the metric is continuous there. Contrary to expectations, we find that the geometry is not smooth, and the horizon becomes singular whenever a wave is present. Both five dimensional and six dimensional black strings are

R. Arnowitt, Pran Nath

The ability of linear colliders to test physics at the post-GUT scale is investigated. Using current estimates of measurements available at such accelerators, it is seen that soft breaking masses can be measured with errors of about (1-20)%. Three classes of models in the post-GUT region are examined: models with universal soft breaking masses at the string

T. Mannel, S. Wolf

A QCD based calculation of the photon spectrum in semi-inclusive $η_Q$ decays is performed. The method applied is an effective theory based on a 1/m_Q expansion of QCD.

D. Ebert, V. Ch. Zhukovsky

Dynamical fermion mass generation in external chromomagnetic fields is considered at non--zero temperature. The general features of dynamical chiral symmetry breaking ($DχSB$) are investigated for several field configurations in relation to their symmetry properties and the form of the quark spectrum. According to the fields, there arises dimensional reducti

R. J. Crewther

The Broadhurst-Kataev conjecture, that the ``discrepancy&#39;&#39; in the connection with the $π^0 \to γγ$ anomaly equals the beta function $β(\barα)$ times a power series in the effective coupling $\barα$, is proven to all orders of perturbative quantum chromodynamics. The use of nested short-distance expansions is justified via Weinberg&#39;s power-countin

Yu. M. Shabelski, D. Treleani

We discuss the experimental indications on the behaviour of F_2(x,Q^2) at small x both in proton and nuclear targets. By comparing the parametrizations of the data we conclude that shadowing correction effects in a proton target can appear at a noticeable level for x=(2 - 4)\times10^{-4} and Q^2\sim 10^1 GeV^2, namely inside the HERA regime.

Peter Kroll

The analysis of the $πγ$ transition form factor provides severe constraints on the pion&#39;s wave function. This information is used to examine charmonium decays into two pions critically. It will be argued that the standard perturbative QCD analysis of these reactions fails, i.e. the need for additional contributions can convincingly be demonstrated. Colou

Manuel Drees

It is pointed out that loop corrections involving heavy quarks and their superpartners can re-introduce a state with 99.5% higgsino purity as a viable cold Dark Matter candidate. Such corrections can increase the mass splitting between the three higgsino-like states of the MSSM by several GeV, which results in a suppression of the co-annihilation rate by a f

C. S. Kim

Talk is given at the YITP International Workshop -- `Recent Developments in QCD and Hadron Physics&#39;. Recent CDF data of the inclusive jet cross section shows anomalous deviation around large transverse momentum $p_{T}(j)\approx 200 \sim 350$ GeV. Is it possible to interpret the anomaly in terms of virtual SUSY effects. The answer is `NO&#39;, because we

A. Zheludev, S. Maslov, G. Shirane, Y. Sasago

We report an observation of a commensurate-incommensurate phase transition in a Dzyaloshinskii-Moriya spiral magnet Ba_2CuGe_2O_7. The transition is induced by applying a magnetic field in the plane of spin rotation. In this experiment we have direct control over the strength of the commensurate potential, while the preferred incommensurate period of the spi

L. Gorelik, S. Kulinich, Yu. Galperin, R. I. Shekhter

We consider the energy stored in a one-dimensional ballistic ring with a barrier subject to a linearly time-dependent magnetic flux. An exact analytic solution for the quantum dynamics of electrons in the ring is found for the case when the electro-motive force ${\cal E}$ is much smaller than the level spacing, $Δ$. Electron states exponentially localized in

R. Verberg, I. M. de Schepper, M. J. Feigenbaum, E. G. D. Cohen

The asymptotic frequency $ω$, dependence of the dynamic viscosity of neutral hard sphere colloidal suspensions is shown to be of the form $η_0 A(ϕ) (ωτ_P)^{-1/2}$, where $A(ϕ)$ has been determined as a function of the volume fraction $ϕ$, for all concentrations in the fluid range, $η_0$ is the solvent viscosity and $τ_P$ the Péclet time. For a soft potential

Jose A. Cuesta, Yuri Martinez-Raton

We present a regularization of the recently proposed fundamental-measure functional for a mixture of parallel hard cubes. The regularized functional is shown to have right dimensional crossovers to any smaller dimension, thus allowing to use it to study highly inhomogeneous phases (such as the solid phase). Furthermore, it is shown how the functional of the

Stefan Kehrein, Andreas Mielke

A new approach to dissipative quantum systems modelled by a system plus environment Hamiltonian is presented. Using a continuous sequence of infinitesimal unitary transformations the small quantum system is decoupled from its thermodynamically large environment. Dissipation enters through the observation that system observables generically decay completely i

P. Chandra, M. V. Feigelman, L. B. Ioffe, D. M. Kagan

History-dependence and ageing are studied in the low-temperature glass phase of a long-range periodic Josephson array. This model is characterized by two parameters, the number of wires ($2N$) and the flux per unit strip ($α$); in the limit $N \to \infty$ and fixed $α\ll 1$ the dynamics of the model are described by the set of coupled integral equations, whi

Gianaurelio Cuniberti, Maura Sassetti, Bernhard Kramer

We show that the non-linear dc transport in a Luttinger liquid with interaction of finite range in the presence of an impurity is governed by a sum rule which causes the charging energy to vanish.

Maura Sassetti, Gianaurelio Cuniberti, Bernhard Kramer

The non-linear current-voltage characteristic of a tunnel junction between two Luttinger systems is calculated for an interaction with finite range. Coulomb blockade features are found. The dissipative resistance, the capacitance and the external impedance, which were introduced ad hoc in earlier theories, are obtained in terms of the electron-electron inter

Gertjan van Noord

This paper describes an efficient and robust implementation of a bi-directional, head-driven parser for constraint-based grammars. This parser is developed for the OVIS system: a Dutch spoken dialogue system in which information about public transport can be obtained by telephone. After a review of the motivation for head-driven parsing strategies, and head-

D. Pierotti

A spherical shell model for turbulence, obtained by coupling $N$ replicas of the Gledzer, Okhitani and Yamada shell model, is considered. Conservation of energy and of an helicity-like invariant is imposed in the inviscid limit. In the $N \to \infty$ limit this model is analytically soluble and is remarkably similar to the random coupling model version of sh

Philip D. Mannheim

We suggest that the conventional need for overwhelming amounts of astrophysical dark matter should be regarded as a warning to standard gravity rather than as merely a challenge to it, and show that the systematics of galactic rotation curve data can just as readily point in the direction of the equally covariant conformal gravity alternative. In particular

P. Serlemitsos, A. Ptak, T. Yaqoob

We present the results of ASCA observations of a heterogenous sample of 15 spiral galaxies. 8 are LINERs or low-luminosity AGN (LLAGN), 5 are starburst galaxies and 2 are normal spiral galaxies. We find that in all cases the ASCA spectra can be described by a canonical model consisting of a power-law with a photon index ~ 1.7-2.0, plus a soft optically thin

R. Capuzzo-Dolcetta, A. Tesseri

Dynamical friction and tidal disruption are effective mechanisms of evolution of globular cluster systems, especially in non-axysimmetric galaxies with a central compact nucleus. With a semi-analytical approach based on the knowledge of the dependence of the dynamical friction and tidal disruption effects on the relevant parameters, we are able to follow the

R. Capuzzo-Dolcetta, L. Vignola

The radial distribution of globular clusters in our Galaxy, M31 and M87 is studied and compared with that of halo stars. The globular cluster distributions seem significantly flatter than those of the stars bulge. Assuming this is a consequence of an evolution of the globular cluster distribution in these galaxies, a comparison with the (unevolved) stellar d

E. Brocato, S. Savaglio, G. Raimondo

We present preliminary results on the effects of SNIa explosions on the Spectral Energy Distribution (SED) of distant galaxies and the possible modifications which may occur in integrated spectra, magnitudes and colours of simple galaxy models of different ages and metallicities few days after a SNIa event.

C. Vignali, R. Audano, A. Comastri, M. Cappi

Results of an ASCA X-ray observation of NGC 4507 are presented. The spectrum is best parameterized by a double power law (or a partial covering) model plus a narrow FeK$α$ emission line likely due to the line-of-sight absorption matter. The data require also an emission line at $\sim$ 0.9 keV consistent with NeIX, which may indicate that the soft X-ray emiss

C. Vignali, A. Comastri, M. Cappi, G. G. C. Palumbo

The results of the 0.1-10 keV spectral analysis of IC 5063 (Narrow Line Radio Galaxy) and NGC 3998 (LINER) are presented. In both cases there is evidence of a FeK$α$ emission line, but its width is poorly constrained. The highly absorbed spectrum of IC 5063 is well described by a double power law model. The X-ray luminosity of a few $\times$ 10$^{43}$ ergs s

C. Vignali, A. Comastri, M. Cappi, G. G. C. Palumbo

Results of the X-ray spectral analysis of the high-redshift radio-quiet quasar Q1101-264 are presented. The ASCA spectrum suggests a marginal evidence of a FeK$α$ emission line at about 2 keV (observer&#39;s frame). Both the ASCA and ROSAT spectra are well fitted by a power law with spectral slope $Γ$$\sim$1.9. This is the first 0.3-30 keV spectrum (rest fra

Yang Chen, Jie-Hao Huang

We find that a non-axisymmetric bow shock model, with an appropriate choice of parameters, could fit the line splitting velocity field of the cone-like H$α$ nebula in NGC 4945 better than a canonical cone model. Meanwhile, the bow shock model could also reproduce the morphology of the H$α$ nebula. The bow shock results from the interaction of the galactic su

David C. Koo, Rafael Guzman, Jesus Gallego, Greg D. Wirth

We present new size, line ratio, and velocity width measurements for six strong emission-line galaxies in the galaxy cluster, Cl 0024+1654, at redshift z~0.4. The velocity widths from Keck spectra are all narrow (30<sigma<120 km/s), with three profiles showing double peaks. Four galaxies have low masses (M<10^{10} Mo). Whereas three galaxies were previously

G. Kaniadakis, A. Lavagno, P. Quarati

In this paper we will show that, because of the long-range microscopic memory of the random force, acting in the solar core, mainly on the electrons and the protons than on the light and heavy ions (or, equally, because of anomalous diffusion of solar core constituents of light mass and of normal diffusion of heavy ions), the equilibrium statistical distribu

Romeel Dave&#39;, John Dubinski, Lars Hernquist

We describe PTreeSPH, a gravity treecode combined with an SPH hydrodynamics code designed for massively parallel supercomputers having distributed memory. Our computational algorithm is based on the popular TreeSPH code of Hernquist & Katz (1989). PTreeSPH utilizes a domain decomposition procedure and a synchronous hypercube communication paradigm to build s

Eanna E. Flanagan, Scott A. Hughes

We estimate the expected signal-to-noise ratios (SNRs) from the three phases (inspiral,merger,ringdown) of coalescing binary black holes (BBHs) for initial and advanced ground-based interferometers (LIGO/VIRGO) and for space-based interferometers (LISA). LIGO/VIRGO can do moderate SNR (a few tens), moderate accuracy studies of BBH coalescences in the mass ra

Ariyeh Maller, Ricardo Flores, Joel Primack

Spheroidal components of spiral galaxies have been considered the only dynamically important component in gravitational lensing studies thus far. Here we point out that including the disk component can have a significant effect, depending on the disk inclination, on a variety of lensing properties that are relevant to present studies and future surveys. As a

J. -R. Cudell, Kyungsik Kang, Sung Ku Kim

Adopting the philosophy à la Donnachie and Landshoff that simple pole exchanges could account for all data of total, elastic and diffractive scattering cross sections to present energies, we show that such simple pole fits to $pp$ and ${\bar p}p$ total cross sections are indeed very successful. We assess the uncertainties of the various parameters by making

L. V. Avdeev, M. Yu. Kalmykov

Pole masses of quarks in the quantum chromodynamics are calculated to the two-loop order in the framework of the regularization by dimensional reduction. For the diagram with a light quark loop, the non-Euclidean asymptotic expansion is constructed with the external momentum on the mass shell of a heavy quark.

Thomas Krajewski

It is known that the spin structure on a Riemannian manifold can be extended to noncommutative geometry using the notion of a spectral triple. For finite geometries, the corresponding finite spectral triples are completely described in terms of matrices and classified using diagrams. When tensorized with the ordinary space-time geometry, finite spectral trip

R. Banerjee, J. Barcelos-Neto

Using the general notions of Batalin, Fradkin, Fradkina and Tyutin to convert second class systems into first class ones, we present a gauge invariant formulation of the massive Yang-Mills theory by embedding it in an extended phase space. The infinite set of correction terms necessary for obtaining the involutive constraints and Hamiltonian is explicitly co

F. Ghaboussi

It is shown that the canonical flux quantization, which is described by the uncertainty relation on the phase space of the flux system, can result in the quantization of Hall-measures. Further it is shown that the polarization of this phase space, which is necessary for its quantization, results in the vanishing of longitudinal resistivity and conductivity.

Andrei Demichev

A definition is given and the physical meaning of quantum transformations of a non-commutative configuration space (quantum group coactions) is discussed. It is shown that non-commutative coordinates which are transformed by quantum groups are the natural generalization of the notion of a tensor operator for usual groups and that the quantum group coactions

D. Boyanovsky, H. J. de Vega, R. Holman

At the end of the inflationary stage of the early universe, profuse particle production leads to the reheating of the universe. Such explosive particle production is due to parametric amplification of quantum fluctuations for the unbroken symmetry case (appropriate for chaotic inflation), or spinodal instabilities in the broken symmetry phase(which is the ca

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

We present new results on the Fundamental Plane of galaxies in two rich clusters, Cl1358+62 at $z=0.33$ and MS2053--04 at $z=0.58$, based on Keck and HST observations. Our new data triple the sample of galaxies with measured Fundamental Plane parameters at intermediate redshift. The early-type galaxies in these clusters define very clear Fundamental Plane re

D. Cule, T. Hwa

The effect of heterogeneous sequence composition on the denaturation of double stranded DNA is investigated. The resulting pair-binding energy variation is found to have a negligible effect on the critical properties of the smooth second order melting transition in the simplest (Peyrard-Bishop) model. However, sequence heterogeneity is dramatically amplified

G. C. McLaughlin, G. M. Fuller, J. R. Wilson

We study the early evolution of the electron fraction (or, alternatively, the neutron-to-proton ratio) in the region above the hot proto-neutron star formed after a supernova explosion. We study the way in which the electron fraction in this environment is set by a competition between lepton (electron, positron, neutrino, and antineutrino) capture processes

Lu-Ming Duan, Guang-Can Guo

Cooperative effects in the loss (the amplitude damping) and decoherence (the phase damping) of the qubits (two-state quantum systems) due to the inevitable coupling to the same environment are investigated. It is found that the qubits undergo the dissipation coherently in this case. In particular, for a special kind of input states (called the coherence-pres

Jørgen Ellegaard Andersen, Josef Mattes, Nicolai Reshetikhin

In this paper we define an algebra structure on the vector space $L(Σ)$ generated by links in the manifold $Σ\times [0,1]$ where $Σ$ is an oriented surface. This algebra has a filtration and the associated graded algebra $L_{Gr}(Σ)$ is naturally a Poisson algebra. There is a Poisson algebra homomorphism from the algebra of chord diagrams $ch(Σ)$ on $Σ$ to $L

Alexander A. Voronov

This paper extends Kontsevich&#39;s ideas on quantizing Poisson manifolds. A new differential is added to the Hodge decomposition of the Hochschild complex, so that it becomes a bicomplex, even more similar to the classical Hodge theory for complex manifolds.

A. N. Ivanov, N. I. Troitskaya, M. Faber, H. Oberhummer

The S-wave scattering length of the strong pion-deuteron (pi D) scattering is calculated in the relativistic field theory model of the deuteron suggested in [1,2].The theoretical result agrees well with the experimental data. The important role of the Delta-resonance contribution to the elastic pi D-scattering is confirmed.

R. Pichler, H. Oberhummer, Attila Csoto, S. A. Moszkowski

We search for three-alpha resonances in C-12 by using the complex scaling method in a microscopic cluster model. All experimentally known low-lying natural-parity states are localized. For the first time we unambiguously show that the 0+_2 state in C-12, which plays an important role in stellar nucleosynthesis, is a genuine three-alpha resonance.

Z. Papp

We propose a three-potential formalism for the three-body Coulomb scattering problem. The corresponding integral equations are mathematically well-behaved and can succesfully be solved by the Coulomb-Sturmian separable expansion method. The results show perfect agreements with existing low-energy $n-d$ and $p-d$ scattering calculations.

Giovanni Landi

These lectures notes are an intoduction for physicists to several ideas and applications of noncommutative geometry. The necessary mathematical tools are presented in a way which we feel should be accessible to physicists. We illustrate applications to Yang-Mills, fermionic and gravity models, notably we describe the spectral action recently introduced by Ch

R. S. Bhalerao, S. K. Gupta

We present a method of analyzing invariant-mass spectra of kaon pairs resulting from decay of $ϕ$ mesons produced in high-energy heavy-ion collisions. It can be used to extract the shifts in the mass and the width ($ΔM$ and $ΔΓ$) of the $ϕ$ mesons when they are inside the dense matter formed in these collisions. We illustrate our method with the help of avai

A. Erdas, C. W. Kim, T. H. Lee

We calculate the finite temperature self-energy for neutrinos in the presence of a constant magnetic field in a medium in the unbroken $SU(2) \otimes U(1)$ model. We obtain the exact dispersion relation for such neutrinos and find that the thermal effective mass is modified by the magnetic field. We also find a simple analytic expression for the dispersion r

Yuval Grossman, Yosef Nir

We analyze the decay $K_L \to π^0 ν\bar ν$ in a model independent way. If lepton flavor is conserved the final state is (to a good approximation) purely CP even. In that case this decay mode goes mainly through CP violating interference between mixing and decay. Consequently, a theoretically clean relation between the measured rate and electroweak parameters

Alexander Kusenko, Gino Segre

Neutral currents induced matter oscillations of electroweak-active (anti-)neutrinos to sterile neutrinos can explain the observed motion of pulsars. In contrast to a recently proposed explanation of the pulsar birth velocities based on the electron to tau (muon) neutrino oscillations [hep-ph/9606428], the heaviest neutrino (either active or sterile) would ha

F. Pisano, M. D. Tonasse

The quest of a vanishing cosmological constant is considered in the simplest anomaly-free chiral gauge extension of the electroweak standard model where the new physics is limited to a well defined additional flavordynamics above the Fermi scale, namely up to a few TeVs by matching the gauge coupling constants at the electroweak scale, and with an extended s

M. Beneke, V. M. Braun, L. Magnea

We analyse power corrections to longitudinal and transverse fragmentation processes in e^+ e^- annihilation, based on the assumption of ultraviolet dominance of power corrections. Under this assumption, we determine the dependence of power corrections on the scaling variable x from the infrared renormalon asymptotics of leading power coefficient functions. O

E. L. Feinberg

Very dense and/or hot hadronic substance (e.g. the one with energy density greatly exceeding that of a normal nucleus) transforms itself into a subhadronic substance which obeys macroscopic classical physics, in particular suffers phase transitions. The most popular Single Phase Transition Model (SPTM) assumes that the new phase is the Quark Gluon Plasma (QG

Joe Sato

I examine how large violation of CP and T is allowed in long base line neutrino experiments. When we attribute both the atmospheric neutrino anomaly and the solar neutrino deficit to neutrino oscillation we may have a sizable T violation effect proportional to the ratio of two mass differences; it is difficult to see CP violation since we can&#39;t ignore th

A. Pich

The total $τ$ hadronic width can be accurately calculated using analyticity and the operator product expansion. The theoretical analysis of this observable is updated to include all available perturbative and non-perturbative corrections. The experimental determination of $α_s(M_τ^2)$ and its actual uncertainties are discussed.

G. Camici, M. Ciafaloni

We investigate the consistency requirements of the next-to leading BFKL equation with the renormalization group, with particular emphasis on running coupling effects and NL anomalous dimensions. We show that, despite some model dependence of the bare hard Pomeron, such consistency holds at leading twist level, provided the effective variable $α_s(t) log(1/x)

Tsukasa Kawanishi

In neutral kaon system, we always use non-hermitian Hamiltonian for convenience of treating decay process, unitarity seems to be lost. If we take decay channels (ππ, πππ, π\ellνetc.) into account, however, Hamiltonian of the whole system must be hermitian. We attempt to derive an effective Hamiltonian with respect to only K^0, $\bar{K}^0$ states, starting fr

John D. Barrow

We present an analysis of the cosmological evolution of matter sources with small anisotropic pressures. This includes electric and magnetic fields, collisionless relativistic particles, gravitons, antisymmetric axion fields in low-energy string cosmologies, spatial curvature anisotropies, and stresses arising from simple topological defects. We calculate th

Qing Chen

We present a proof of the generalized Nitsche&#39;s conjecture proposed by W.H.Meeks III and H. Rosenberg: For $t\ge 0$, let $P_t$ denote the horizontal plane of height $t$ over the $x_1,x_2$ plane. Suppose that $M \subset R^3$ is a minimal annulus with the boundary contains in $P_0$ and that $M$ intersects every $P_t$ in a simple closed curve. Then $M$ has

Maxim A. Makeev, Albert-Laszlo Barabasi

Ion bombardment is known to enhance surface diffusion and affect the surface morphology. To quantify this phenomenon we calculate the ion-induced diffusion constant and its dependence on the ion energy, flux and angle of incidence. We find that ion bombardment can both enhance and suppress diffusion and that the sign of the diffusion constant depends on the

R. P. Michel, A. Chaiken, C. T. Wang, L. E. Johnson

(001) oriented NiO/NiFe bilayers were grown on single crystal MgO (001) substrates by ion beam sputtering in order to determine the effect that the crystalline orientation of the NiO antiferromagnetic layer has on the magnetization curve of the NiFe ferromagnetic layer. Simple models predict no exchange anisotropy for the (001)-oriented surface, which in its

V. I. Yukalov

A particular type of random dynamical processes is considered, in which the stochasticity is introduced through randomly fluctuating parameters. A method of local multipliers is developed for treating the local stability of such dynamical processes corresponding to infinite--dimensional dynamical systems. The method is illustrated by several examples, by the

Nigel B. Wilding

We report an extensive Monte Carlo study of critical end point behaviour in a symmetrical binary fluid mixture. On the basis of general scaling arguments, singular behaviour is predicted in the diameter of the liquid-gas coexistence curve as the critical end point is approached. The simulation results show clear evidence for this singularity, as well as conf

R. Mélin, P. Butaud

The Glauber dynamics of various models (REM-like trap models, Brownian motion, BM model, Ising chain and SK model) is analyzed in relation with the existence of ageing. From a finite size Glauber matrix, we calculate a time $τ_w(N)$ after which the system has relaxed to the equilibrium state. The case of metastability is also discussed. If the only non zero

Peter Schupp

We discuss classical and quantum symmetries of extended Hubbard models. The quantum symmetries are shown to be related to the known superconducting SU(2) symmetry of the original Hubbard model at half filling via generalized Lang-Firsov transformations and Drinfel&#39;d twists. (Based on talk at the 21st ICGTM in Goslar, July 1996)

Adrienne L. Fairhall, Brindesh Dhruva, Victor S. L&#39;vov, Itamar Procaccia

We present the first experimental tests of the recently derived fusion rules for Navier-Stokes (N-S) turbulence. The fusion rules address the asymptotic properties of many-point correlation functions as some of the coordinates coalesce, and form an important ingredient of the nonperturbative statistical theory of turbulence. Here we test the fusion rules whe

Thomas J. Loredo, Ira M. Wasserman

We use Bayesian methods to study anisotropic models for the distribution of gamma ray burst intensities and directions reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts. We analyze data obtained using both the 64 ms and 1024 ms measuring timescales. We study both purely local models in which burst sources (``bursters&#39;&#39;) are presume

Thomas J. Loredo, Ira M. Wasserman

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters&#39;&#39;) is isotropic. We study both phenomenological and cosmological source distribution models, using Bayes&#39;s theorem both to infer unknown pa

E. Dwek

Interstellar dust models are facing a &#34;carbon crisis&#34;, so called because recent observations suggest that the abundance of carbon available for dust in the interstellar medium is less than half of the amount required to be tied up in graphite grains in order to explain the interstellar extinction curve. This paper presents an detailed assessment of a

M. P. Allen, J. E. Horvath

The Crab pulsar has suffered in 1975 and 1989 two glitches in which the frequency did not relaxed to the extrapolated pre-glitch value but rather spun up showing long-term changes in the frequency derivative dot Omega. This particular behaviour has been interpreted as evidence for an evolution of the torque acting upon the star. A variable torque may be rela

Matt Burleigh, Martin Barstow, Tom Fleming

The ROSAT WFC survey has provided us with evidence for the existence of a previously unidentified sample of hot white dwarfs (WD) in non-interacting binary systems, through the detection of EUV and soft X-ray emission. These stars are hidden at optical wavelengths due to their close proximity to much more luminous main sequence (MS) companions (spectral type

J. C. B. Papaloizou, J. D. Larwood, R. P. Nelson, C. Terquem

We describe some recent nonlinear three dimensional hydrodynamic simulations of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc midplane. The calculations are relevant to a number of observed astrophysical phenomena, including the precession of jets associated with young stars, the high spectral index

Paul T. O&#39;Brien, Karen M. Leighly

The International AGN Watch has monitored a number of radio-quiet and radio-loud Active Galactic Nuclei - the most luminous objects in the universe. We present a review of the main observational results from the continuum monitoring campaigns, concentrating on those which aim to quantify the simultaneous ultraviolet to X-ray variability characteristics. Thes

Lauri Jetsu

The most significant periodicities in the terrestrial impact crater record are due to the human-signal: the bias of assigning integer values for the crater ages. This bias seems to have eluded the proponents and opponents of real periodicity in the occurrence of these events, as well as the theorists searching for an extraterrestrial explanation for such per

M. P. van Haarlem, C. S. Frenk, S. D. M. White

We investigate the importance of projection effects in the identification of galaxy clusters in 2D galaxy maps and their effect on the estimation of cluster velocity dispersions. A volume limited galaxy catalogue that was derived from a Standard CDM N-body simulation was used. We select clusters using criteria that match those employed in the construction of

Lars Petersen, Peter Gammelgaard

The dust extinction towards bright HII regions in NGC 598 and NGC 5457 has been studied in detail by forming line ratios of Balmer and Paschen emission lines covering a large wavelength range. Three homogeneous models of the geometrical distribution of the emitting sources and the obscuring dust have been tested. Only for low extinctions can the data be fit

Philip Kaaret, Eric Ford, Kaiyou Chen

Quasi-periodic oscillations (QPOs) at frequencies near 1000 Hz were recently discovered in several x-ray binaries containing neutron stars. Two sources show no correlation between QPO frequency and source count rate (Berger et al. 1996, Zhang et al. 1996). We suggest that the QPO frequency is determined by the Keplerian orbital frequency near the marginally

Bruce M. Boghosian, Washington Taylor

Algorithms are described for efficiently simulating quantum mechanical systems on quantum computers. A class of algorithms for simulating the Schrodinger equation for interacting many-body systems are presented in some detail. These algorithms would make it possible to simulate nonrelativistic quantum systems on a quantum computer with an exponential speedup

R. M. L. Evans, W. C. K. Poon, M. E. Cates

We show that the rate of separation of two phases of different densities (e.g. gas and solid) can be radically altered by the presence of a metastable intermediate phase (e.g. liquid). Within a Cahn-Hilliard theory we study the growth in one dimension of a solid droplet from a supersaturated gas. A moving interface between solid and gas phases (say) can, for

J. L. F. Barbon

We define fermionic collective coordinates for type-IIB Dirichlet instantons and discuss some effects of the associated fermionic zero modes within the dilute gas framework. We show that the standard rules for clustering of zero modes in the dilute limit, and the fermion-exchange interactions follow from world-sheet Ward identities. Fermion exchange is stron

C. A. Marsh, J. M. Yeomans

Dissipative particle dynamics (DPD) is a relatively new technique which has proved successful in the simulation of complex fluids. We caution that for the equilibrium achieved by the DPD simulation of a simple fluid the temperature depends strongly on the time step. An analytic expression for the dependence is obtained and shown to agree well with simulation