December 1996 arXiv papers — page 2

A. A. Bolokhov, T. A. Bolokhov, I. S. Manida, M. V. Polyakov

The near-threshold expansion of the $ππ$ amplitude is developed using the crossing-covariant independent variables. The independent threshold parameters entering the real part of the amplitude in an explicitly Lorentz-invariant way are free from restrictions of isotopic and crossing symmetries. Parameters of the expansion of the imaginary part are recovered

I. V. Andreev

It is argued that distribution over the number of charged and neutral soft chiral pions are very broad if they are emitted coherently.

Michel Dubois-Violette, Thierry Masson

We study the noncommutative differential geometry of the algebra of endomorphisms of any SU(n)-vector bundle. We show that ordinary connections on such SU(n)-vector bundle can be interpreted in a natural way as a noncommutative 1-form on this algebra for the differential calculus based on derivations. We interpret the Lie algebra of derivations of the algebr

M. Ullner, B. Jönsson, C. Peterson, O. Sommelius

Monte Carlo simulations and variational calculations using a Gaussian ansatz are applied to a model consisting of a flexible linear polyelectrolyte chain as well as to an intrinsically stiff chain with up to 1000 charged monomers. Addition of salt is treated implicitly through a screened Coulomb potential for the electrostatic interactions. For the flexible

Suncica Elezovic-Hadzic, Milan Knezevic

We study the critical behavior of surface-interacting self-avoiding random walks on a class of truncated simplex lattices, which can be labeled by an integer $n\ge 3$. Using the exact renormalization group method we have been able to obtain the exact values of various critical exponents for all values of n up to n=6. We also derived simple formulas which des

Kazuo Hida

The low energy properties of the spin-1/2 random Heisenberg chain with ferromagnetic and antiferromagnetic interactions are studied by means of the density matrix renormalization group (DMRG) and real space renormalization group (RSRG) method for finite chains. The results of the two methods are consistent with each other. The deviation of the gap distributi

D. B. Bailey, A. M. Tikofsky, R. B. Laughlin

We compute the dynamical magnetic susceptibility of the t-J model in its commensurate flux phase at low hole doping. We compare the calculations with experiments and exact diagonalization studies.

R. Castro, T. Sauer

In principle, the state space of a chaotic attractor can be partially or wholly reconstructed from interspike intervals recorded from experiment. Under certain conditions, the quality of a partial reconstruction, as measured by the spike train prediction error, can be increased by adding noise to the spike creation process. This phenomenon for chaotic system

Fagen Xie, Gang Hu

Clustering bifurcations are investigated by considering models of globally coupled map lattices. Typical classes of clustering bifurcations are revealed. The clustering bifurcation thresholds of the coupled system are closely related to the bifurcation structures of single map. In particular, cluster-doubling bifurcation induced period-doubling bifurcations

E. Athanassoula, I. Puerari, A. Bosma

We use N-body simulations to study the formation of rings in a disc galaxy by the impact of a small spherical companion. Both barred and nonbarred target discs are considered. We discuss the effect of the properties of the target disc (distribution of mass in the disc, velocity dispersion, etc.) as well as of the mass and orbit of the companion on the proper

William H. Waller

Resolution of nearby giant HII regions into their stellar and nebular constituents provides fundamental insights for interpreting more distant and powerful starburst activity. The following summarizes recent advances in our understanding of the stellar populations and nebular energetics associated with giant HII regions. Photometry and spectroscopy of ionizi

B. M. Gaensler, R. N. Manchester, L. Staveley-Smith, A. K. Tzioumis

We present seven years of radio observations of SN 1987A made with the Australia Telescope Compact Array. At 1.4, 2.4, 4.8 and 8.6 GHz, the flux density of the radio remnant has increased monotonically since emission was redetected 1200 days after the explosion. On day 3200, the remnant was expanding at 2800 +/- 400 km/s, which we interpret as indicating sig

William H. Waller, Frank Varosi, Francois Boulanger, Seth W. Digel

Using the IRAS Infrared Sky Survey Atlas, we have made 60 x 60 deg mosaics of the far-infrared emission in the Milky Way. By applying a median normalizing spatial filter, we were able to eliminate the strong gradient in brightness towards the Galactic midplane. The resulting images reveal a "froth" of superposed filaments, voids, and shells. This fin

P. H. E. Tiesinga, T. J. Hagenaars, J. E. van Himbergen, Jorge V. José

We have numerically and analytically studied ac+dc driven Josephson-junction arrays with a single vortex or with a single vortex-antivortex pair present. We find single-vortex steps in the voltage versus current characteristics (I-V) of the array. They correspond microscopically to a single vortex phase-locked to move a fixed number of plaquettes per period

D. V. Ahluwalia

These notes present a critique of the standard three-flavor neutrino oscillation framwork. The design proposal of the MINOS at Fermilab based on a two mass eigenstate framework may require serious reconsideration if there is strong mixing between all three flavors of neutrinos. For the LSND and KARMEN neutrino oscillation experiments, the amplitude of neutri

Bo-yu Hou, Wen-li Yang

As the Yangian double with center,which is deformed from affine algebra by the additive loop parameter $\hbar$ ,we get the commuting relation and the bosonization of quantum $\hbar$-deformed Virasoro algebra. The corresponding Miura transformation, associated screening operators and the BRST charge have been studied. Moreover, we also constructe the bosoniza

Alexander Gorsky

We suggest the brane interpretation of the integrable dynamics behind the exact solution to the N=2 SUSY YM theory. Degrees of freedom of the Calogero type integrable system responsible for the appearance of the spectral Riemann surfaces originate from the collective coordinates of the dynamical branes. The second Whitham type integrable system corresponds t

K. Hamada

We study vertex operators for super Yang-Mills and multi D-branes in covariant form using Green-Schwarz formalism. We introduce the contact terms naturally and prove space-time supersymmetry and gauge invariance. The nonlinear realization of broken supersymmetry in the presence of D-branes is also discussed. The shift of fermionic coordinate δ^{(-)}Ψ=ηbecome

Chigak Itoi, Hisamitsu Mukaida, Yoshinori Sakamoto

We calculate connected correlators in Gaussian orthogonal, unitary and symplectic random matrix ensembles by the replica method in the 1/N-expansion. We obtain averaged one-point Green's functions up to the next-to-leading order O(1/N) and wide two-level correlators up to the first nontrivial order O(1/N^2) and wide three-level correlators up to the firs

J. Harnad

A comparison is made between bispectral operator pairs and dual pairs of isomonodromic deformation equations. Through examples, it is shown how operators belonging to rank one bispectral algebras may be viewed equivalently as defining 1-parameter families of rational first order differential operators with matricial coefficients on the Riemann sphere, whose

Chaz Schlindwein

The preservation theorems for semi-properness, hemi-properness, and pseudo-completeness hold for countable support iterations as well as revised countable support iterations, notwithstanding the fact that the "factor lemma" fails for the countable support versions. Example: The countable support iteration of Namba forcing over a ground model of CH do

Sanjay Jain

Random matrix theory (RMT) provides a common mathematical formulation of distinct physical questions in three different areas: quantum chaos, the 1-d integrable model with the $1/r^2$ interaction (the Calogero-Sutherland-Moser system), and 2-d quantum gravity. We review the connection of RMT with these areas. We also discuss the method of loop equations for

S. Higuchi, C. Itoi, S. M. Nishigaki, N. Sakai

We study critical and universal behaviors of unitary invariant non-gaussian random matrix ensembles within the framework of the large-N renormalization group. For a simple double-well model we find an unstable fixed point and a stable inverse-gaussian fixed point. The former is identified as the critical point of single/double-arc phase transition with a dis

I. Ya. Aref'eva, O. A. Rytchkov

An algebraic method for a general construction of intersecting p-brane solutions in diverse spacetime dimensions is discussed. An incidence matrix describing configurations of electric and magnetic fields is introduced. Intersecting p-branes are specified by solutions of a system of characteristic algebraic equations for the incidence matrix. This set of cha

Ernest Ma

Assuming the existence of a supersymmetric U(1) gauge factor at the TeV energy scale (motivated either by the superstring-inspired E_6 model or low-energy electroweak phenomenology), several important consequences are presented. The two-doublet Higgs structure at the 100 GeV energy scale is shown to be different from that of the Minimal Supersymmetric Standa

K. Adel, F. J. Ynduráin

We show how the sum of a hard singularity, $F_{2H}(x,Q^2_0)\sim x^{-λ}$ and a soft Pomeron $F_{2P}(x,Q^2_0)\sim Const.$ for the singlet piece of the structure function $F_{2S}=F_{2H}+F_{2P}$ for $Q_0^2\sim a few GeV^2$, plus a saturating expression for the strong coupling, $\tildeα_s(Q^2)=4π/β_0 log[(Q^2+Λ^2)/Λ^2]$ give an excellent description of experiment

Naoyuki Haba, Nobuhito Maru, Takeo Matsuoka

In the framework of the dynamical supersymmetry breaking we construct the messenger sector as the effective theory of supersymmetry breaking sector, which is based on SU(3) \times SU(2) model of Affleck, Dine and Seiberg. In our model, messenger superfields with non-renormalizable interaction are contained. By minimizing the scalar potential, we show that th

I. V. Baryakhtar

The Boltzmann type kinetic equation for solitons in Nonlinear Schrödinger equation has been constructed on the base of analysis of two soliton collision. Possible applications for Langmuir solitons in plasma and solitons in optic fiber are discussed.

Lam Hui, Nickolay Y. Gnedin

We develop an efficient method to study the effects of reionization history on the temperature-density relation of the intergalactic medium in the low density limit (overdensity less than 5). It is applied to the study of photo-reionization models in which the amplitude, spectrum and onset epoch of the ionizing flux, as well as the cosmology, are systematica

P. O. Petrucci, G. Henri

We present a new model of accretion disk where the disk luminosity is entirely due to the reprocessing of hard radiation impinging on the disk. The hard radiation itself is emitted by a hot point source above the disk, that could be physically realized by a strong shock terminating an aborted jet. This hot source contains ultra-relativistic leptons scatterin

Lothar Göttsche, Don Zagier

We prove structure theorems for the Donaldson invariants of 4-manifolds with b_+=1, similar to those of Kronheimer and Mrowka in the case b_+>1: We show that for a 4-manifold with b_+=1 and two different period points F, G on the boundary of the positive cone, the difference of the Donaldson invariants at F and G satisfies the k^{th}-order simple type condit

N. Chamoun

We use QCD sum rules to determine directly the leading-twist non-singlet operator matrix elements based on calculations of three-point correlator functions in configuration space. We find a different result from that obtained by integrating the structure functions' expressions obtained by Belyaev and Ioffe based on calculations of four-point correlators

G. E. Arutyunov, L. O. Chekhov, S. A. Frolov

It is shown that the classical L-operator algebra of the elliptic Ruijsenaars-Schneider model can be realized as a subalgebra of the algebra of functions on the cotangent bundle over the centrally extended current group in two dimensions. It is governed by two dynamical r and $\bar{r}$-matrices satisfying a closed system of equations. The corresponding quant

R. Rattazzi, U. Sarid

We explore some topics in the phenomenology of gauge-mediated SUSY-breaking scenarios having a large hierarchy of Higgs VEVs, $v_U/v_D = tanβ\gg 1$. Some motivation for this scenario is first presented. We then use a systematic, analytic expansion (including some threshold corrections) to calculate the $μ$ parameter needed for proper electroweak breaking and

M. Gedalin, T. C. Scott, Y. B. Band

We study solitary wave solutions of the higher order nonlinear Schrodinger equation for the propagation of short light pulses in an optical fiber. Using a scaling transformation we reduce the equation to a two-parameter canonical form. Solitary wave (1-soliton) solutions exist provided easily met inequality constraints on the parameters in the equation are s

H. Awata, H. Kubo, S. Odake, J. Shiraishi

Virasoro-type symmetries and their roles in solvable models are reviewed. These symmetries are described by the two-parameter Virasoro-type algebra $Vir_{p,q}$ by choosing the parameters p and q suitably.

V. M. Kustov

The Green function of the quark-antiquark system in the confining background field is analysed using the Feynman-Schwinger formalism. The Hamiltonian for the case of massive spinning quarks is obtained in the form containing essentially nonhermitian part. The eigenvalue problem for such type of the Hamiltonian is discussed, and it is shown that no complex ei

M. A. Ivanov, M. P. Locher, V. E. Lyubovitskij

We report the calculation of electromagnetic form factors of nucleons within a relativistic three-quark model with Gaussian shape for the nucleon-quark vertex. The allowed region for two adjustable parameters, the range parameter $Λ_N$ in the Gaussian and the constituent quark mass $m_q$, is obtained from fitting the data for magnetic moments and electromagn

Alexandr K. Guts

The following mechanism of action of Time machine is considered. Let space-time $<V^4, g_{ik}>$ be a leaf of a foliation F of codimension 1 in 5-dimensional Lorentz manifold $<V^5, G_{AB}>$. If the Godbillon-Vey class $GV(F) \neq 0$ then the foliation F has resilient leaves. Let $V^4$ be a resilient leaf. Hence there exists an arbitrarily small neighborhood

Rafael Herrera, Simon M. Salamon

We investigate the geometry and topology of a standard moduli space of stable bundles on a Riemann surface, and use a generalization of the Verlinde formula to derive results on intersection pairings.

L. N. Shchur, J. R. Heringa, H. W. J. Blöte

We investigate the mechanism that leads to systematic deviations in cluster Monte Carlo simulations when correlated pseudo-random numbers are used. We present a simple model, which enables an analysis of the effects due to correlations in several types of pseudo-random-number sequences. This model provides qualitative understanding of the bias mechanism in a

Vl. V. Papoyan, A. M. Povolotsky

We apply the renormalization group approach to the sandpile on the triangular lattice. The only attractive fixed point is found. The obtained fixed point height probabilities are compared with numerical simulations. The value of critical exponent of avalanche size distribution is found to be $τ=1.36$. The probabilities of the sand transition are compared wit

Yukiyasu Ozeki

We derive a rigorous dynamical relation on aging phenomena -- the aging relation -- for Ising spin glasses using the method of gauge transformation. The waiting-time dependence of the auto-correlation function in the zero-field-cooling process is equivalent with that in the field-quenching process. There is no aging on the Nishimori line; this reveals argume

J. I. Katz

The recent discovery of a planet in an orbit with eccentricity $e = 0.63 \pm 0.08$ around the Solar-type star 16 Cyg B, together with earlier discoveries of other planets in orbits of significant eccentricity, raises the question of the origin of these orbits, so unlike the nearly circular orbits of our Solar system. In this paper I consider close encounters

J. I. Katz

The outstanding task of gamma-ray burst astronomy is to test the hypothesis that they are at cosmological distances. This can be done by determining the coordinates of at least a few bursts to ~ 15&#39;&#39; or better. If they are in distant galaxies, the next task is to determine from which component of the galaxies the bursts originate; sub-arcsecond posit

Xiangdong Shi

A formalism that simultaneously searches for the monopolar and dipolar peculiar velocities is presented. The formalism is applied to (1) the Mark III catalogue, (2) Lauer and Postman&#39;s Abell cluster catalogue, and (3) Riess et al.&#39;s Type Ia supernova sample. The emphasis is drawn to the monopolar peculiar velocities, i.e., peculiar Hubble flows, with

Thomas Vojta, D. Belitz, R. Narayanan, T. R. Kirkpatrick

We consider the quantum ferromagnetic transition at zero temperature in clean itinerant electron systems. We find that the Landau-Ginzburg-Wilson order parameter field theory breaks down since the electron-electron interaction leads to singular coupling constants in the Landau-Ginzburg-Wilson functional. These couplings generate an effective long-range inter

J. Kondev, J. B. Marston

We study the localization transition in the integer quantum Hall effect as described by the network model of quantum percolation. Starting from a path integral representation of transport Green&#39;s functions for the network model, which employs both complex (bosonic) and Grassman (fermionic) fields, we map the problem of localization to the problem of diag

N. Dorey, V. V. Khoze, M. P. Mattis

We construct the n-instanton action for the above model with gauge group SU(2), as a function of the collective coordinates of the general self-dual configurations of Atiyah, Drinfeld, Hitchin and Manin (ADHM). We calculate the quantum modulus u = <Tr(A^2)> at the 1-instanton level, and find a discrepancy with Seiberg and Witten&#39;s proposed exact solution

V. M. Belyaev, A. Oganesian

We consider the procedure of determination of induced quark condensates in the QCD sum rule approach. It is noted that the previous estimations of this value were very rough. It is shown, that the detailed analyses of this parameter of QCD vacuum leads to the conclusion that the value of the tensor susceptibility has opposite sign and much larger than estima

Chong-Sun Chu, Pei-Ming Ho

We give a natural definition of a Poisson Differential Algebra. Consistence conditions are formulated in geometrical terms. It is found that one can often locally put the Poisson structure on differential calculus in a simple canonical form by a coordinate transformation. This is in analogy with the standard Darboux&#39;s theorem for symplectic geometry. For

J. M. Landsberg

Let $X^n\subset C^{n+a}$ or $X^n\subset P^{n+a}$ be a patch of an analytic submanifold of an affine or projective space, let $x\in X$ be a general point, and let L^k be a linear space of dimension k osculating to order m at x. If m is large enough, one expects L to be contained in X and thus X contains a linear space of dimension kthrough almost every point.

M. K. Volkov

A chiral U(3)*U(3) Lagrangian containing, besides the usual meson fields, their first radial excitations is constructed. The Lagrangian is derived by bosonization of the Nambu-Jona-Lasinio quark model with separable non-local interactions, with form factors corresponding to 3-dimensional ground and excited state wave functions. The spontaneous breaking of ch

Ken-Ichi Aoki, Keiichi Morikawa, Jun-Ichi Sumi, Haruhiko Terao

We study the chiral critical behaviors of QED by using Non-Perturbative Renormalization Group (NPRG). Taking account of the non-ladder contributions, our flow equations are free from the gauge parameter ($α$) dependence. We clarify the chiral phase structure, and calculate the anomalous dimension of $\barψψ$, which is enhanced compared to the ladder approxim

Stephan Narison

We compute the masses and decay widths of gluonia using QCD spectral sum rules and low-energy theorems. In the scalar sector, one finds a gluonium having a mass $M_G=(1.5\pm 0.2)$ GeV, which decays mainly into the $U(1)_A$ channels $ηη&#39;$ and 4$π^0$. However, for a consistency of the whole approach, one needs broad-low mass gluonia (the $σ$ and its radial

A. V. Dotsenko

The report discusses the slave-fermion representations of the t-J model and describes another representation, in which fermions and bosons are completely commuting and in which the properties of fermions are directly related to the properties of physical holes. For a study of the system in the new representation at half-filling, interaction of fermions with

Mirjam Cvetic, Donam Youm

We present intersecting p-brane solutions of eleven-dimensional supergravity (M-branes) which upon toroidal compactification reduce to non-extreme ``rotating&#39;&#39; black holes. We identify harmonic functions, associated with each M-brane, and non-extremality functions, specifying a deviation from the BPS limit. These functions are modified due to the ang

R. Carroll

We discuss certain kernels on a Riemann surface, constructed mainly via Baker Akhiezer functions, and indicate relations to dispersionless theory.

R. Carroll, J. Chang

We survey some topics involving the Whitham equations, concentrating on the role of the Baker Akhiezer function in averaging. Some connections to symplectic geometry and Seiberg-Witten theory are indicated.

A. Herrera, O. Kechkin

The (3+d)-dimensional Einstein-Kalb-Ramond theory reduced to two dimensions is considered. It is shown that the theory allows two different Ernst-like $d \times d$ matrix formulations: the real non-dualized target space and the Hermitian dualized non-target space ones. The O(d, d) symmetry is written in a SL(2,R) matrix-valued form in both cases. The Kramer-

A. H. Bilge, T. Dereli, Ş. Koçak

Self-dual 2-forms in D=2n dimensions are characterised by an eigenvalue criterion. The equivalence of various definitions of self-duality is proven. We show that the self-dual 2-forms determine a n^2-n+1 dimensional manifold S_{2n} and the dimension of the maximal linear subspaces of S_{2n}$ is equal to the Radon-Hurwitz number of linearly independent vector

M. A. Ivanov, J. G. Korner, P. Kroll, V. E. Lyubovitskij

Exclusive semileptonic decays of bottom and charm baryons are considered within a relativistic three-quark model with a Gaussian shape for the baryon-three-quark vertex and standard quark propagators. We calculate the baryonic Isgur-Wise functions, decay rates and asymmetry parameters.

P. Jain, S. D. Joglekar

Phenomenological implications of the Z&#39; in SU(3)xSU(3)xU(1) extension of the standard model are studied. The model improves the fit for R_b as well as the high E_T jet cross section observed by CDF.

Maria Krawczyk

Present data do not rule out the light neutral Higgs particle h or A with mass below 40--50 GeV in the framework of the general 2HDM (&#34;Model II&#34;). The status of this model in a light of existing LEP I data and a potential of the new muon experiment (g-2), the measurement of photon-gluon and gluon-gluon fusion at HERA as well as photon-photon fusion a

Ken-Ichi Aoki, Keiichi Morikawa, Wataru Souma, Jun-ichi Sumi

The non-perturbative Wegner-Houghton renormalization group is analyzed by the local potential approximation in O(N) scalar theories in d-dimensions $(3\leq d\leq 4)$. The leading critical exponents νare calculated in order to investigate the effectiveness of the local potential approximation by comparing them with the other non-perturbative methods. We show

A. V. Belitsky

We calculate the leading twist valence quark distribution in the pion in the franework of QCD sum rules with nonlocal condensates. Particular attention has been paid to the correct account of the bilocal power corrections.

Carl R. Schmidt

A simple solution to the BFKL equation is obtained as a series in the number of real gluons emitted with transverse momentum greater than some small cutoff $μ$. This solution reveals physics inside the BFKL ladder which is hidden in the standard inclusive solution, and lends itself to a straightforward Monte Carlo implementation. With this approach one can e

Mark J. Stevens, Steve Plimpton

We present results of molecular dynamics simulations of strong, flexible polyelectrolyte chains in solution with added salt. The effect of added salt on the polyelectrolyte chain structure is fully treated for the first time as a function of polymer density. Systems above and below the Manning condensation limit are studied. The chain contraction due to adde

Stephen W. Pierson

The behavior of clean layered superconductors in the presence of a finite electric current and in zero-magnetic field behavior is addressed. The structure of the current temperature phase diagram and the properties of each of the four regions will be explained. We will discuss the expected current voltage and resistance characteristics of each region as well

R. S. Gonnelli, G. A. Ummarino, V. A. Stepanov

We discuss the limits and the correct utilization of the standard program for the inversion of Eliashberg equations and the determination of the electron-phonon spectral function and the coulomb pseudopotential from tunneling measurements in high-Tc superconductors. In order to compare the calculated density of states with the experimental one, we introduce

Yan V. Fyodorov, Alexander D. Mirlin

We study overlap of two different eigenfunctions as compared with self-overlap in the framework of an infinite-dimensional version of the disordered tight-binding model. Despite a very sparse structure of the eigenstates in the vicinity of Anderson transition their mutual overlap is still found to be of the same order as self-overlap as long as energy separa

H. Weber, W. Paul, W. Kob, K. Binder

We present Monte Carlo simulations of a dense polymer melt which shows glass-transition-like slowing-down upon cooling, as well as a build up of nematic order. At small wave vectors q this model system shows excess scattering similar to that recently reported for light-scattering experiments on some polymeric and molecular glass-forming liquids. For our mode

Hualin Shi, Wei-Mou Zheng

A Bose gas in an external potential is studied by means of the semi-classical approximation. Analytical results are derived for the energy of an interacting Bose gas in a generic power-law trapping potential. An expression for the chemical potential below the critical temperature is also obtained. The theoretical results are in qualitative agreement with a r

A. Ohnishi, J. Randrup

Interacting argon atoms are simulated with a recently developed quantum Langevin transport treatment that takes approximate account of the quantum fluctuations inherent in microscopic many-body descriptions based on wave packets. The mass distribution of the atomic clusters is affected significantly near the critical temperature and thus it may be important

J. Kumicak, X. de Hemptinne

Thermodynamic relations are derived from first principles of mechanics for non-equilibrium processes. Since the key role herein is played by the law of increase of entropy, the latter is analyzed at first. It is shown that its derivation for isolated systems does not allow one to say too much about thermodynamic properties in non-equilibrium conditions. From

Michael E. Flatte, Jeff M. Byers

The electronic structure near defects (such as impurities) in superconductors is explored using a new, fully self-consistent technique. This technique exploits the short-range nature of the impurity potential and the induced change in the superconducting order parameter to calculate features in the electronic structure down to the atomic scale with unprecede

Yu Shi

It is shown that calculus can apply on a fractal structure with the condition that the infinitesimal limit of change of the variable is larger than the lower cut-off of the fractal structure, and an assumption called local decomposability. As an application, it is shown that the angular projection of a fractal distribution in 3-dimensional space is not homog

Paul H. Frampton, Otto C. W. Kong

A spontaneously-broken CP provides an alternative to the KM mechanism for CP violation with the advantage that the strong CP problem is solved. We consider, for such a model with a new gauged U(1), the incorporation of low-energy supersymmetry and find the constraints on alignment and squark degeneracy. The conclusion is that although the $\barθ$ constraints

Yu Shi

The power-law dependence of the angle in the angular projection of galaxy distribution is explained by assuming that in the spherical shells within a small angle the distributions are also fractal. If this local angular fractal is possessed, a fractal structure is angularly-isotropic at each occupied point though inhomogeneous, and is compatible with the pre

M. L. Kulic, V. Oudovenko

In the recent theory of strong correlations by Kulic and Zeyher it has been shown that by lowering doping concentration a forward peak in the charge scattering channel is developed. Accordingly, near the optimal doping the nonmagnetic scattering is pronounced in the d-channel and its effect on d-wave pairing is reduced. As a consequence, d-wave pairing is ro

R. Girard, E. Davoust

We have counted the number of references in 1179 papers published in Astronomy and Astrophysics over twenty years. The number of references has increased by 60% between 1975 and 1995, reflecting the increase (by the same amount) of the literature which must be cited, and of the number of pages per paper. There are 1.5 times more references in predominantly o

M. Praehofer, H. Spohn

We generalize the surface growth model of Gates and Westcott to arbitrary inclination. The exact steady growth velocity is of saddle type with principal curvatures of opposite sign. According to Wolf this implies logarithmic height correlations, which we prove by mapping the steady state of the surface to world lines of free fermions with chiral boundary con

A. Volmer, T. Nattermann

Wearless dry friction of an elastic block of weight N, driven by an external force F over a rigid substrate, is investigated. The slider and substrate surfaces are both microscopically rough, interacting via a repulsive potential that depends on the local overlap. The model reproduces Amontons&#39;s laws which state that the friction force is proportional to

H. G. Dosch, J. Kripfganz, A. Laser, M. G. Schmidt

The effective action describing the long range fluctuations in the high temperature phase of the electroweak standard theory is a strongly coupled SU(2)-Higgs-model in three dimensions. We outline in detail a model in which the spatial correlation scales in this phase are calculated as inverse relativistic bound state masses. Selection rules for these states

L. Wilets, M. A. Alberg, S. Pepin, Fl. Stancu

We present a study of the $^4$He charge distribution based on realistic nucleonic wave functions and incorporation of the nucleon&#39;s quark substructure. The central depression of the proton point density seen in modern four-body calculations is too small by itself to lead to a correct description of the charge distribution. We utilize six-quark structures

A. D. Martin, R. G. Roberts, M. G. Ryskin, W. J. Stirling

We present a formulation which allows heavy quark (c, b, ...) mass effects to be explicitly incorporated in both the coefficient functions and the splitting functions in the parton evolution equations. We obtain a consistent procedure for evolution through the threshold regions for c anti-c and b anti-b production in deep inelastic scattering, which allows t

C. M. Canali, W. Stephan, L. Y. Gorelik, R. I. Shekhter

We study a model of two concentric onedimensional rings with incommensurate areas $A_1$ and $A_2$, in a constant magnetic field. The two rings are coupled by a nonhomogeneous inter-ring tunneling amplitude, which makes the one-particle spectrum chaotic. For noninteracting particles the energy of the many-body ground state and the first excited state exhibit

H. Russ, M. H. Soffel, M. Kasai, G. Börner

For the first time we calculate quantitatively the influence of inhomogeneities on the global expansion factor by averaging the Friedmann equation. In the framework of the relativistic second-order Zel&#39;dovich-approximation scheme for irrotational dust we use observational results in form of the normalisation constant fixed by the COBE results and we chec

Yasumichi Aoki

We study the finite-temperature electroweak phase transition of the minimal standard model within the four-dimensional SU(2) gauge-Higgs model. Monte Carlo simulations are performed for intermediate values of the Higgs boson mass in the range $50 \lesssim M_H \lesssim 100$GeV on a lattice with the temporal size $N_t=2$. The order of the transition is systema

Michael Martin Nieto

After beginning with a short historical review of the concept of displaced (coherent) and squeezed states, we discuss previous (often forgotten) work on displaced and squeezed number states. Next, we obtain the most general displaced and squeezed number states. We do this in both the functional and operator (Fock) formalisms, thereby demonstrating the necess

Roberto Alvarez, Martin van Hecke, Wim van Saarloos

In many pattern forming systems that exhibit traveling waves, sources and sinks occur which separate patches of oppositely traveling waves. We show that simple qualitative features of their dynamics can be compared to predictions from coupled amplitude equations. In heated wire convection experiments, we find a discrepancy between the observed multiplicity o

E. L. Lomon

Experimental evidence has been growing for the existence of both molecular and exotic dibaryons. The former are dominated by hadron and the latter by quark-gluon degrees of freedom. Exotic dihadrons are of particular interest because their properties are closely related to the parameters and non-perturbative properties of QCD models. Molecular structures pro

Nimai C. Mukhopadhyay, J. -F. Zhang, M. Benmerrouche

We analyze the available data on eta photo- and electroproduction, around W~1535 MeV, in the framework of the effective Lagrangian approach, and extract, in a nearly model-independent fashion, the electrostrong amplitude for the gamma+N--> N*(1535)--> N+eta processes. Quark model approaches are shown to be quite inadequate to explain this property at all Q^2

Tomasz S. Mrowka, Peter S. Ozsváth, Baozhen Yu

In this paper, we investigate the Seiberg-Witten gauge theory for Seifert fibered spaces. The monopoles over these three-manifolds, for a particular choice of metric and perturbation, are completely described. Gradient flow lines between monopoles are identified with holomorphic data on an associated ruled surface, and a dimension formula for such flows is c

Lionel Carminati, Bruno Iochum, Daniel Kastler, Thomas Schucker

Connes has extended Einstein&#39;s principle of general relativity to noncommutative geometry. The new principle implies that the Dirac operator is covariant with respect to Lorentz and internal gauge transformations and the Dirac operator must include Yukawa couplings. It further implies that the action for the metric, the gauge potentials and the Higgs sca

Flavio S. Nogueira

The N component scalar tricritical theory is considered in a non-perturbative setting. We derive non-perturbative beta functions for the relevant couplings in $d\leq 3$. The beta functions are obtained through the use of an exact evolution equation for the so called effective average action. In d=3 it is established the existence of an ultraviolet stable fix

Christian Wieczerkowski

The renormalized trajectory of massless $ϕ^4$-theory on four dimensional Euclidean space-time is investigated as a renormalization group invariant curve in the center manifold of the trivial fixed point, tangent to the $ϕ^4$-interaction. We use an exact functional differential equation for its dependence on the running $ϕ^4$-coupling. It is solved by means o

Vadim Zeitlin

We comment on the calculation of the Chern-Simons coefficient in (2+1)-dimensional gauge theories at finite chemical potential made by A.N.Sissakian, O.Yu.Shevchenko and S.B.Solganik (hep-th/9608159 and hep-th/9612140).

H. Lu, S. Mukherji, C. N. Pope

We study the relationship between static p-brane solitons and cosmological solutions of string theory or M-theory. We discuss two different ways in which extremal p-branes can be generalised to non-extremal ones, and show how wide classes of recently discussed cosmological models can be mapped into non-extremal p-brane solutions of one of these two kinds. We

Jorgen Randrup

Approximate mean-field equations of motion for the classical chiral field are developed within the linear sigma model by means of a Hartree factorization. Both the approximate and the unapproximated equations of motion are augmented with a Rayleigh cooling term to emulate a uniform expansion, thereby allowing the extraction of observables relevant to the det