June 1997 arXiv papers — page 6

A. N. Kvinikhidze, B. Blankleider

We derive relativistic three-dimensional integral equations describing the interaction of the three-nucleon system with an external electromagnetic field. Our equations are unitary, gauge invariant, and they conserve charge. This has been achieved by applying the recently introduced gauging of equations method to the three-nucleon spectator equations where s

Eugene Levin

This talk is a rather sceptical review of our knowledge and understanding of deep inelastic scattering at low x (high energy). We show that the well known success of the DGLAP evolution equations in describing of experimental HERA data brought more problems and puzzles than answers. We advocate that more systematic theoretical and experimental investigations

Zvi Bern, Lance Dixon, David C. Dunbar, David A. Kosower

We present an overview of techniques developed in recent years for the efficient calculation of one-loop multiparton amplitudes, in particular those relying on unitarity and collinear factorization.

David A. Kosower

Collider data can play an important role in determining the parton distribution functions of the nucleon. I outline a formalism which makes it possible to use next-to-leading order calculations in such an extraction, while minimizing the amount of numerical computation required.

Jian-Jun Yang, Wei Lu

The final-state interaction effects on the inclusive two-particle production in electron-positron annihilation are investigated within the context of the one-photon annihilation approximation. Such effects are characterized by one structure function in the decomposition of the hadronic tensor. On the basis of the positivity, we derived an inequality to bound

K. Hidaka

We study the decays of the charged Higgs boson H^+ within the Minimal Supersymmetric Standard Model. We find that the supersymetric mode 'stop + sbottom-bar' can dominate the H^+ decays in a wide range of the model parameters due to the large Yukawa couplings and mixings of stop and sbottom. Compared to the conventional modes 'tau^+ nu' and &

A. Favara, M. Pieri

This note proposes a method, which can be applied to searches and more in general to any cross section measurement, to maximize the analysis sensitivity.

D. V. Gal'tsov, E. E. Donets

Analytical formulas are presented describing a generic singularity inside the static spherically symmetric black holes in the SU(2) Einstein-Yang-Mills-Higgs theories with triplet or doublet Higgs field. The singularity is spacelike and exhibits a `power-low mass inflation'. Alternatively this asymptotic may be interpreted as a pointlike singularity with

A. S. Rinat, M. F. Taragin, F. Mazzanti, A. Polls

We report dynamical calculations for large-$q$ structure functions of liquid $^4$He at $T$=1.6 and 2.3 K and compare those with recent MARI data. We extend those calculations far beyond the experimental range $q\le 29\Ain$ in order to study the approach of the response to its asymptotic limit for a system with interactions having a strong short-range repulsi

Dimitri Kusnezov, Aurel Bulgac, Gui Do Dang

We study a quantum particle propagating through a ``quantum mechanically chaotic'' background, described by parametric random matrices with only short range spatial correlations. The particle is found to exhibit turbulent-like diffusion under very general situations, without the apriori introduction of power law noise or scaling in the background pro

A. Leclair

We solve for the exact atom-field eigenstates of a single atom in a three dimensional spherical cavity, by mapping the problem onto the anisotropic Kondo model. The spectrum has a rich bound state structure in comparison with models where the rotating wave approximation is made. It is shown how to obtain the Jaynes-Cummings model states in the limit of weak

M. A. Treyer, R. S. Ellis, B. Milliard, J. Donas

We present the first results of an ongoing spectroscopic survey of galaxies selected in the rest-frame ultraviolet. The source catalogue was constructed from a flux-limited sample of stars, galaxies and QSOs imaged at 2000 Åwith the FOCA balloon-borne camera (Milliard et al. 1992). The redshift distribution obtained for 45 galaxies spans 0<z<0.3 and a high f

Chao-Hsi Chang, Cong-Feng Qiao, Jian-Xiong Wang

Within the framework of QED we investigate the inclusive J/ψproduction at $e^+e^-$ colliders. It is expected to be as a further test to the charmonium production mechanisms and QED. We find that at the energies of CESR, BEPC, and TRISTAN (e.g. 4.0 GeV \leq \sqrt s \leq 60 GeV), the contributions of the concerned electromagnetic processes to the $J/ψ$ inclusi

S. O. Alexeyev, M. V. Pomazanov

Four-dimensional black hole solutions generated by the low energy string effective action are investigated outside and inside the event horizon. A restriction for a minimal black hole size is obtained in the frame of the model discussed. Intersections, turning points and other singular points of the solution are investigated. It is shown that the position an

Hitoshi Nishino

We present a theory of N=2 chiral supergravity in (10+2)-dimensions. This formulation is similar to N=1 supergravity presented recently using null-vectors in 12D. In order to see the consistency of this theory, we perform a simple dimensional reduction to ten-dimensions, reproducing the type IIB chiral supergravity. We also show that our supergravity can be

Stathes D. Paganis

The role of Strangeness as a signal of the Quark Gluon Plasma in relativistic heavy ion experiments is discussed. The current experimental status is briefly presented. Several scenarios which explain the CERN data are discussed.

Hans Schoutens

Let K be an algebraically closed field of characteristic zero, endowed with a complete nonarchimedean norm. Let X be a K-rigid analytic variety and Σa semianalytic subset of X. Then the closure of Σin X with respect to the canonical topology is again semianalytic. The proof uses Embedded Resolution of Singularities.

Stanislaw D. Glazek

A matrix model of an asymptotically free theory with a bound state is solved using a perturbative similarity renormalization group for hamiltonians. An effective hamiltonian with a small width, calculated including the first three terms in the perturbative expansion, is projected on a small set of effective basis states. The resulting small hamiltonian matri

Keiichi Akama

By solving the compositeness condition, under which the Yukawa-type model coincides the NJL type model, we obtain the expressions for the effective coupling constants in terms of the compositeness scale at the next-to-leading order in 1/N. In the NJL model with a scalar composite, the next to leading contributions are too large for N_c=3. In the induced gaug

Hsiang-nan Li, B. Tseng

We include nonfactorizable soft gluon corrections into the perturbative QCD formalism for exclusive nonleptonic heavy meson decays, which combines factorization theorems and effective field theory. These corrections are classified according to their color structures, and exponentiated separately to complete the Sudakov resummation up to next-to-leading logar

J. A. Casas, G. B. Gelmini

We examine the conditions for a viable Affleck-Dine baryogenesis in supergravity (SUGRA) scenarios, finding surprisingly strong constraints on the type of SUGRA theory. These constraints are beautifully fulfilled by string-based SUGRA models provided that inflation is driven by a modulus (T) field.

T. M. Tripp, L. Lu, B. D. Savage

As part of a program to study the relationship between QSO Lyman alpha clouds and galaxies at low redshifts, we have obtained a high signal-to-noise far UV spectrum of H 1821+643 [z(em) = 0.297] with the G140L grating of the GHRS. The spectrum, which has a resolution of FWHM = 150 km/s and S/N ~ 100:1, is adequate for detection of weak Ly alpha clouds with e

M. Eracleous, J. P. Halpern, A. M. Gilbert, J. A. Newman

It has been suggested that the peculiar double-peaked Balmer lines of certain broad-line radio galaxies come from individual broad-line regions associated with the black holes of a supermassive binary. We continue to search for evidence of the radial velocity variations characteristic of a double-lined spectroscopic binary that are required in such a model.

Jose Wudka

The top-quark system as a probe for new physics is considered using a consistent, gauge-invariant effective Lagrangian approach. The magnitude of new effects is estimated and the results are applied to top production through W fusion. Other processes are also briefly discussed.

Lev I. Deych, Alexander A. Lisyansky

We show that an impurity embedded in an ionic crystal can give rise to a novel kind of local states. These states exist within a polariton gap of a material and are a mix of excitations of the crystal, such as phonons or excitons, and the transverse electromagnetic field. The electromagnetic component of the states along with the corresponding excitations of

R. Durrer, M. Kunz, C. Lineweaver, M. Sakellariadou

We compute cosmic microwave background angular power spectra for scaling seed models of structure formation. A generic parameterization of the energy momentum tensor of the seeds is employed. We concentrate on two regions of parameter space inspired by global topological defects: O(4) texture models and the large-N limit of O(N) models. We use $χ^{2}$ fittin

Paolo De Los Rios, Angelo Valleriani, Jose Luis Vega

Using the Bak-Sneppen model of biological evolution as our paradigm, we investigate in which cases noise can be substituted with a deterministic signal without destroying Self-Organized Criticality (SOC). If the deterministic signal is chaotic the universality class is preserved; some non-universal features, such as the threshold, depend on the time correlat

K. Kurokawa, M. Sasaki, M. Osaki, O. Hirota

This paper presents some examples of quantum reliability function for the quantum communication system in which classical information is transmitted by quantum states. In addition, the quantum Cut off rate is defined. They will be compared with Gallager&#39;s reliability function for the same system.

Katsunori Kawamura

For an infinitesimal symplectic action of a Lie algebra ${\goth g}$ on a symplectic manifold, we construct an infinitesimal crossed product of Hamiltonian vector fields and Lie algebra ${\goth g}$. We obtain its second crossed product in case ${\goth g}=R$ and show an infinitesimal version for a theorem type of Takesaki duality.

Adel Bilal, Frank Ferrari

We present a detailed study of the analytic structure, BPS spectra and superconformal points of the $ N=2 $ susy $ SU(2) $ gauge theories with $ N_f=1,2,3 $ massive quark hypermultiplets. We compute the curves of marginal stability with the help of the explicit solutions for the low energy effective actions in terms of standard elliptic functions. We show th

Yu Shi, Ido Kanter, David Kessler

Distributions of triplets in some genetic sequences are examined and found to be well described by a 2-parameter Markov process with a sparse transition matrix. The variances of all the relevant parameters are not large, indicating that most sequences gather in a small region in the parameter space. Different sequences have very near values of the entropy ca

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

The spherically symmetric reduction of higher dimensional Einstein-scalar theory leads to lower dimensional dilatonic gravity with dilaton coupled scalar (for example, from 4D to 2D system). We calculate trace anomaly and anomaly induced effective action for 2D and 4D dilaton coupled scalars. The large-N effective action for 2D quantum dilaton-scalar gravity

Won Young Hwang, In Gyu Koh, Yeong Deok Han

We show that a secure quantum protocol for coin tossing exist. The existence of quantum coin tossing support the conjecture of D.Mayers [Phys.Rev.Lett. 78, 3414(1997)] that only asymmetrical tasks as quantum bit commitment are impossible.

S. J. Brodsky, F. Hautmann, D. E. Soper

Perturbative QCD predicts the behavior of scattering at high energies and fixed (sufficiently large) transferred momenta in terms of the BFKL pomeron (or short distance pomeron). We study the prospects for testing these predictions in two-photon processes at LEP200 and a possible future e+ e- collider. We argue that the total cross section for scattering two

J. Bland-Hawthorn, K. C. Freeman, P. J. Quinn

In spiral galaxies, the HI surface density declines with increasing radius to a point where it is seen to truncate dramatically in the best observed cases. It was anticipated that if the ambient radiation field is sufficiently strong, there exists a maximum radius beyond which the cold gas is unable to support itself against ionization. We have now succeeded

Hiromichi Nakazato

A one-dimensional scattering problem off a $δ$-shaped potential is solved analytically and the time development of a wave packet is derived from the time-dependent Schrödinger equation. The exact and explicit expression of the scattered wave packet supplies us with interesting information about the &#34;time delay&#34; by potential scattering in the asymptot

C. P. Sun H. B. Gao, H. F. Dong, S. R. Zhao

The microscopic approach quantum dissipation process presented by Yu and Sun [Phys. Rev., A49(1994)592, A51(1995)1845] is developed to analyze the wave function structure of dynamic evolution of a typical dissipative system, a single mode boson soaked in a bath of many bosons. In this paper, the wave function of total system is explicitly obtained as a produ

Alice Fialowski, Dmitry Fuchs

The notion of singular one-parameter deformation of a Lie algebra is introduced. It is shown that the complex infinite-dimensional Lie algebra of polynomial vector fields in C with trivial 1-jet at the origin has such singular deformation.

William Mitchell

We show that every Jonsson cardinal is Ramsey in the Steel core model, provided that this model exists and there is no model with a Woodin cardinal. This basic result is improved in two directions. First, we prove the same result for delta-Jonsson and delta-Erdos cardinals, where delta is any regular cardinal smaller than kappa. These notions correspond to J

V. E. Korepin, N. A. Slavnov

We consider the dynamical correlation functions of the quantum Nonlinear Schrodinger equation. In a previous paper we found that the dynamical correlation functions can be described by the vacuum expectation value of an operator-valued Fredholm determinant. In this paper we show that a Riemann-Hilbert problem can be associated with this Fredholm determinant.

I. Ya. Arefeva, I. V. Volovich

We consider a matrix model with d matrices NxN and show that in the limit of large N and d=0 the model describes the knot diagrams. The same limit in matrix string theory is also discussed. We speculate that a prototypical M(atrix) without matrix theory exists in void.

Yosuke Imamura

We investigate the zero modes of the Kaluza-Klein monopole in M-theory and show that the Born-Infeld action and the Chern-Simons term of a D6-brane are reproduced to quadratic order in the field strength of the U(1) field on the brane.

Hsin-Chia Cheng, Jonathan L. Feng, Nir Polonsky

If supersymmetric partners of the known particles have masses at the multi-TeV scale, they will not be directly discovered at planned future colliders and decouple from most observables. However, such superpartners also induce non-decoupling effects that break the supersymmetric equivalence of gauge boson couplings $g_i$ and gaugino couplings $h_i$ through s

Erwin Mirkes, Dieter Zeppenfeld

Dijet production in DIS is an important laboratory for testing our understanding of perturbative QCD. Flexible NLO Monte Carlo programs allow to investigate general jet definition schemes. For forward jet production at $p_{Tj} \approx Q$ and $x_{jet} >> x$ the NLO predictions fall well below HERA data, thus providing evidence for BFKL dynamics.

Stephen Rock, Peter Bosted

We compare data on the proton structure function from SLAC experiments in the range of x between 0.7 and 0.97 in and near the resonance region with previous empirical fits to Deep Inelastic Scattering and with calculations from parton distribution functions. The data is in rough agreement with the empirical fits, but is an order of magnitude higher than the

Eva-Maria Kabuss

A summary of the results on deep inelastic muon nucleon and muon nucleus scattering experiments performed by the NMC collaboration is presented.

Jose Wudka

I present a brief overview of the advantages of using a consistent effective Lagrangian approach in parameterizing virtual new physics effects. I then apply the formalism to certain top-quark processes.

Zhenping Li

Quantitative signatures of glueballs in $J/ψ$ radiative decays are discussed. Further experimental and theoretical investigations are sugessted.

Robin G. Stuart

It is shown how to construct exactly gauge-invariant S-matrix elements for processes involving unstable gauge particles such as the $W$ and $Z^0$ bosons. The results are applied to derive a physically meaningful expression for the cross-section $σ(e^+e^-\to Z^0Z^0)$ and thereby provide a solution to the long-standing problem of the unstable particle. The pro

K. G. Chetyrkin, B. A. Kniehl, M. Steinhauser

We present in analytic form the matching conditions for the strong coupling constant alpha_s^(n_f)(mu) at the flavour thresholds to three loops in the modified minimal-subtraction scheme. Taking into account the recently calculated coefficient beta_3 of the Callan-Symanzik beta function of quantum chromodynamics, we thus derive a four-loop formula for alpha_

Gia Dvali, Alex Pomarol

In conventional supergravity theories, supersymmetry is broken by a non-zero F-term, and the cosmological constant is fine tuned to zero by a constant in the superpotential W. We discuss a class of supergravity theories with vanishing F-terms but $W \not= 0$ being generated dynamically. The cosmological constant is assumed to be cancelled by a non-zero D-ter

C. D. Froggatt, M. Gibson, H. B. Nielsen

The combined requirements, of (i) a natural solution to the fermion mass hierarchy problem and (ii) an explanation of both the atmospheric and solar neutrino problems, lead to an essentially unique picture of neutrino masses and mixing angles. The electron and muon neutrinos are quasi-degenerate in mass with maximal mixing, giving $ν_e - ν_μ$ vacuum oscillat

Shuo-Hong Guo, Xiang-Qian Luo

We review the recent advances in the Hamiltonian formulation of lattice gauge theory for approaching the continuum physics. In particular, vacuum wave function and glueball spectrum calculations by coupled cluster method with truncation scheme preserving the continuum behavior are described.

John D. Barrow, Janna Levin

Yang-Mills color fields evolve chaotically in an anisotropically expanding universe. The chaotic behaviour differs from that found in anisotropic Mixmaster universes. The universe isotropizes at late times, approaching the mean expansion rate of a radiation-dominated universe. However, small chaotic oscillations of the shear and color stresses continue indef

Othmar Brodbeck, Markus Heusler

Using the Kaluza-Klein structure of stationary spacetimes, a framework for analyzing stationary perturbations of static Einstein-Yang-Mills configurations with bosonic matter fields is presented. It is shown that the perturbations giving rise to non-vanishing ADM angular momentum are governed by a self-adjoint system of equations for a set of gauge invariant

D. V. Gal&#39;tsov, E. E. Donets, M. Yu. Zotov

Singularities inside static spherically symmetric black holes in the SU(2) Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theories are investigated. Analytical formulas are presented describing oscillatory and power law metric behavior near spacelike singularities in generic solutions.

Johan Kustermans

Woronowicz introduced the functional calculus for normal operators in Hilbert C*-modules. The aim of this paper is to translate, if possible, some basic properties of the functional calculus in Hilbert spaces to the Hilbert C*-module framework.

J. Bonet Avalos, A. D. Mackie

The stochastic differential equations for a model of dissipative particle dynamics with both total energy and total momentum conservation in the particle-particle interactions are presented. The corresponding Fokker-Planck equation for the evolution of the probability distribution for the system is deduced together with the corresponding fluctuation-dissipat

V. S. Podolsky, A. A. Lisyansky

We derive the off-shell scattering matrix for a spherical scatterer. The result obtained generalizes the off-on-shell matrix commonly used in the theory of scalar waves propagation in random media.

V. S. Podolsky, A. A. Lisyansky

A new method of path averaging for waves propagating in a random dilute system of identical scatterers is developed. The scattering matrix of such a system is calculated. The method systematically takes into account repeating scatterings on the same scatterer and effects of correlations. Results obtained show the significant influence of new effects on the e

Lev I. Deych, D. Zaslavsky, A. A. Lisyansky

In order to study an influence of correlations on the localization properties of classical waves in random superlattices we introduce a generalized random Thue-Morse model as a four-state Markov process with two parameters that determine probabilities of different configurations. It is shown that correlations can bring about a considerable change in the tran

Pep Español

Dissipative particle dynamics (DPD) does not conserve energy and this precludes its use in the study of thermal processes in complex fluids. We present here a generalization of DPD that incorporates an internal energy and a temperature variable for each particle. The dissipation induced by the dissipative forces between particles is invested in raising the i

Parongama Sen, D. Stauffer, U. Gradmann

Effective Curie temperatures measured in Fe monolayer strips agree reasonable with computer sinulations of two-dimensional Ising model strips. The simulations confirm the domain structure seen already by Albano et al.

Jun Zang, S. A. Trugman, A. R. Bishop, H. Röder

In this paper, we study the zero temperature persistent current in a ferromagnetic Kondo lattice model in the strong coupling limit. In this model, there are spontaneous spin textures at some values of the external magnetic flux. These spin textures contribute a geometric flux, which can induce an additional spontaneous persistent current. Since this spin te

Stephane Cueille, Clement Sire

We show that models for homogeneous and heterogeneous nucleation of D-dimensional droplets in a d-dimensional medium are described in mean-field by a modified Smoluchowski equation for the distribution N(s,t) of droplets masses s, with additional terms accounting for exogenous growth from vapor absorption, and injection of small droplets when the model allow

Armando Vieira, M. Begona Torres, Carlos Fiolhais, L. Carlos Balbas

We compare Kohn-Sham results (density, cohesive energy, size and effect of charging) of the Spherical Averaged Pseudopotential Model with the Stabilized Jellium Model for clusters of sodium and aluminum with less than 20 atoms. We find that the Stabilized Jellium Model, although conceptually and practically more simple, gives better results for the cohesive

Y. N. Skryabin, A. V. Shchanov

The influence of disordering upon critical behavior of the system with hidden degrees of freedom is considered. It is shown that there is a tricritical behavior in the constrained system, while in the unconstrained system only phase transitions of the second order occur.

Ayumi Fujita

We numerically investigate the phenomenological nonlocal Ginzburg-Landau Hamiltonian for two-dimensional superconductors in a strong magnetic field by Langevin equation. We obtain a regular vortex lattice which is very near to the square lattice. We calculate the structure factor and Abrikosov factor at various temperatures. We also evaluate the specific hea

H. Tajima, J. Shiraishi, M. Kohmoto

We investigate a theoretical model applicable to molecular conductors, such as TTP and $M(dmit)_2$ salts [M=Ni, Pd, Pt], whose charge carriers orig inate from two kinds of molecular orbitals. The model Hamiltonian consists of two independent Hubbard chains. The degree of charge transfer between the two chains is calculated. The results qualitatively agree wi

K. Kimura, Y. Hatsugai, M. Kohmoto

A one-parameter family of models that interpolates between the periodic Anderson model with infinite repulsion at half-filling and a model whose ground state is exactly the Resonating-Valence-Bond state is studied. It is shown numerically that the excitation gap does not collapse. Therefore the ground states of the two models are adiabatically connected.

J. A. Braatz, A. S. Wilson, C. Henkel

A survey for H2O megamaser emission from 354 active galaxies has resulted in the detection of 10 new sources, making 16 known altogether. The galaxies surveyed include a distance-limited sample (covering Seyferts and LINERs with recession velocities < 7000 km s^{-1}) and a magnitude-limited sample (covering Seyferts and LINERs with m(B) <= 14.5). In order to

Roger W. Romani, James M. Cordes, I. -A. Yadigaroglu

We have detected weak soft X-ray emission from the Pulsar Wind Nebula trailing the high velocity star PSR 2224+65 (the `Guitar Nebula&#39;). This X-ray flux gives evidence of γ~10^7 eV particles in the pulsar wind and constrains the properties of the post-shock flow. The X-ray emission is most easily understood if the shocked pulsar wind is partly confined i

Nickolay Y. Gnedin, Lam Hui

We introduce an efficient and accurate alternative to full hydrodynamic simulations, Hydro-PM (HPM), for the study of the low column density Lyman-alpha forest. It consists of a Particle-Mesh solver, modified to compute, in addition to the gravitational potential, an effective potential due to the gas pressure. Such an effective potential can be computed fro

W. Dehnen, J. Bland-Hawthorn, A. Quirrenbach, G. Cecil

We present the kinematics of the ionized gas over the inner 140 arcsec (10 kpc) of NGC 1068 from observations with the HIFI Fabry-Perot interferometer. There is clear evidence for density wave streaming and bar-driven streaming across the field, with bi-symmetric arms that penetrate to within 200 pc of the nucleus. CO maps show linear structures along (altho

Ann Berit Saust

The relation between the Fourier coefficients determined by the light curves of RR Lyrae variables in the Sculptor dwarf galaxy, the M5 cluster, and the unique globular cluster omega-Centauri is investigated. A couple of recent papers claim that it is possible to determine both metallicity and absolute magnitude of RR Lyrae stars from their period and two of

Gabriele Ghisellini

The overall spectra (SED) of blazars, from radio to gamma-ray energies, seem to obey well defined trends, with a continuity of properties between blazars of different classes. To quantify this statement we can either investigate their observed properties (see Fossati et al., this volume), or try to determine their intrinsic physical parameters by applying sp

Thomas Buchert

The averaging problem for inhomogeneous cosmologies is discussed in the form of a disputation between two cosmologists, one of them (RED) advocating the standard model, the other (GREEN) advancing some arguments against it. Technical explanations of these arguments as well as the conclusions of this debate are given by BLUE.

M. Gabriel

We present the results of solar model computation done with the latest Livermore opacities. Models without diffusion, with hydrogen diffusion only and with hydrogen and heavy elements diffusion are considered. The influence of mixing below the convective envelope induced by rotation and angular momentum losses is also discussed. The sound speed of our best m

E. Poretti, C. Koen, P. Martinez, F. Breuer

We present multi-site photometric observations of the F0 IV star HR 2740=QW Pup which reveal it to be a Gamma Dor type variable pulsating with four frequencies: 1.0434, 0.9951, 1.1088, 0.9019 c\d. These data were obtained at the European Southern Observatory and South African Astronomical Observatory over a time baseline spanning from 1997 January 14 to 1997

J. Bland-Hawthorn, S. L. Lumsden, G. M. Voit, G. N. Cecil

The radio jet axis of NGC 1068 is characterised by energetic activity from x-ray to radio wavelengths. Detailed kinematic and polarization studies have shown that this activity is confined to bipolar cones centered on the AGN which intersect the plane of the disk. Thus, molecular clouds at 1 kpc distance along this axis are an important probe of the nuclear

Arturo Alvarez Vazquez

The aim of this paper is to construct an immersion of the Drinfeld moduli schemes in a finite product of infinite Grassmannians, such that they will be locally closed subschemes of these Grassmannians which represent a kind of flag varieties.

Predrag L. Stojkov

A new variant of the exact Fradkin representation of the Green&#39;s function $G_c(x,y|gU)$, defined for arbitrary external potential $U$, is presented. Although this new approach is very similar in spirit to that previously derived by Fried and Gabellini, for certain calculations this specific variant, with its prescribed approximations, is more readily uti

E. G. Berezhko, G. F. Krymsky, V. K. Yelshin, L. T. Ksenofontov

Spectrum and chemical composition of cosmic rays accelerated in supernova remnants are studied on a basis of kinetic approach. The cosmic ray transport equation with the Bohm diffusion coefficient has been numerically solved self-consistently with gas dynamic equations for the underlying flow. Comparison with observational results gives some indications that

Francesco Miniati, T. W. Jones, Andrea Ferrara, Dongsu Ryu

We have studied head-on collisions between equal-mass, mildly supersonic (Mach number 1.5) HI clouds, in a standard Two-phase ISM (T_cl = 74 K, n_cl = 22 cm^-3, χ= 100). We explore the role of various factors, including the radiative cooling parameter η= t_rad/t_coll (t_coll=R_c/v_c), evolutionary modifications on the cloud structure (by colliding clouds ``e

S. P. de Alwis

The M-theory origin of brane creation processes is discussed.

S. Majid

We show that noncommutative differential forms on $k[x]$, $k$ a field, are of the form $Ω^1=k_λ[x]$ where $k_λ\supset k$ is a field extension. We compute the case $C\supset R$ explicitly, where $Ω^1$ is 2-dimensional. We study the induced quantum de Rahm complex, its cohomology and the associated moduli space of flat connections.

B. Chibisov, M. Shifman

Domain-wall solutions in four-dimensional supersymmetric field theories with distinct discrete vacuum states lead to the spontaneous breaking of supersymmetry, either completely or partially. We consider in detail the case when the domain walls are the BPS-saturated states, and 1/2 of supersymmetry is preserved. Several useful criteria that relate the preser

L. S. Kisslinger, T. Meissner

It is essential to know the space-time structure of the nonlocal vacuum condensates for application to medium energy processes. Using the Dyson-Schwinger formalism in the rainbow approximation for the quark propagator, we study the nonlocal quark condensate and model forms for the nonperturbative gluon propagator constrained by fits to local condensates and

B. M. Lewis

There is an approximately 60% detection rate for 1612 MHz masers in association with red, color-selected IRAS sources, though few are detected from the bluer circumstellar shells of Mira variables. On the other hand and complementarily, past, pre-IRAS 22 GHz surveys detected many water masers in association with Mira variables. This paper reports on a 22 GHz

S. Kumano, M. Miyama

Chiral-odd structure function h1 is expected to be measured in polarized Drell-Yan process. We calculate two-loop anomalous dimensions for h1 in the minimal subtraction scheme. Dimensional regularization and Feynman gauge are used for calculating the two-loop contributions. Our results are important in studying Q^2 dependence of h1.

Christoph P. Hofmann

We investigate the low energy properties of Lorentz-invariant theories with a spontaneously broken rotation symmetry O(N) $\to$ O(N--1). The leading coefficients of the low temperature expansion for the partition function are calculated up to and including three loops. Emphasis is put into the special case N=3: it describes the antiferromagnet which has been

Stephen J. Paddison, Lawrence R. Pratt, Thomas Zawodzinski, David W. Reagor

Reported here are theoretical calculations on the triflic acid and water, establishing molecular scale information necessary to modeling of the structure, thermodynamics, and ionic transport of Nafion membranes. To characterize side chain flexibility and accessibility of the acid proton, free energies for rotation of both carbon-sulfur and sulfur-oxygen (hyd

F. Ghaboussi

The two dimensional substructure of general relativity and gravity, and the two dimensional geometry of quantum effect by black hole are disclosed. Then the canonical quantization of the two dimensional theory of gravity is performed. It is shown that the resulting uncertainty relations can explain black hole quantum effects. A quantum gravitational length i

Ken-ichiro Imura, Naoto Nagaosa

We study the effects of long-range Coulomb interaction (LRCI) on the quantum transport in FQH edges with $ν=1/(2k+1)$. We consider two models, i.e., the quasi-particle tunneling (QPT) model and the electron tunneling (ET) model at the point contact. The tunneling conductance $G(T)$ is obtained using the renormalization group treatment. In QPT model, it is fo

G. &#39;t Hooft

A model is proposed in which the Hawking particles emitted by a black hole are treated as an envelope of matter that obeys an equation of state, and acts as a source in Einstein&#39;s equations. This is a crude but interesting way to accommodate for the back reaction. For large black holes, the solution can be given analytically, if the equation of state is

John L. Tonry

B1422+231 and PG1115+080 are gravitational lens systems producing quadruple QSO images where there is real promise that time delays can constrain the Hubble constant. In addition, the lensing galaxies are both part of groups which can play an important role in modelling the lens potential. This article reports redshifts for the lensing galaxies and three nei

Chong Sheng Li, Robert J. Oakes, Jin Min Yang, Hong-Yi Zhou

We evaluate the supersymmetric QCD corrections to single top quark production via $q \bar q&#39;\to t \bar b$ at the Fermilab Tevatron in the minimal supersymmetric model. We find that within the allowed range of squark and gluino masses the supersymmetric QCD corrections can enhance the cross section by a few percent. The combined effects of SUSY QCD, SUSY

Max Tegmark

We assess the accuracy with which future galaxy surveys can measure cosmological parameters by deriving a handy approximation that we validate numerically. We find that galaxy surveys are quite complementary to future Cosmic Microwave Background (CMB) experiments. By breaking parameter degeneracies of the Planck CMB satellite in a cold dark matter cosmology,

J. J. Halliwell, E. Zafiris

We use the decoherent histories approach to quantum theory to compute the probability of a non-relativistic particle crossing $x=0$ during an interval of time. For a system consisting of a single non-relativistic particle, histories coarse-grained according to whether or not they pass through spacetime regions are generally not decoherent, except for very sp

Gerald Cliff

Let B be the crystal basis of the minus part of the quantized enveloping algebra of a semi-simple Lie algebra. Kashiwara has shown that B has a combinatorial description in terms of an embedding of B into the tensor product of B and k abstract crystals B_{i_j}, j=1,2,...,k, where the longest word in the Weyl group is s_{i_1}...s_{i_k}. We give an explicit de