June 1997 arXiv papers — page 15

Alexandre Kabanov, Takashi Kimura

We obtain a simple, recursive presentation of the tautological (κ, ψ, and λ) classes on the moduli space of curves in genus zero and one in terms of boundary strata (graphs). We derive differential equations for the generating functions for their intersection numbers which allow us to prove a simple relationship between the genus zero and genus one potential

Davor Palle

Relationships between gauge, conformal and discrete symmetries in particle physics are analysed. We study also the effect of the electroweak mixing on the cancellation of SU(2) anomalous actions. It is shown that the relation theta_{W} = 2(theta_{12}+theta_{23}+theta_{13}) between the Weinberg angle and the Cabibbo-Kobayashi-Maskawa angles should be satisfie

S. Bertolini, J. O. Eeg, M. Fabbrichesi, E. I. Lashin

After updating the determination of the combination of Kobayashi-Maskawa elements $ \Im V_{td}V^*_{ts}$ according to our new estimate of the parameter $\hat B_K$, we study the CP-violating ratio $ε'/ε$ by means of hadronic matrix elements computed to $O(p^4)$ in the chiral expansion. It is the first time that this order in chiral perturbation theory is i

Arnd Surig

In the standard procedure for calculating the decay rate of a metastable vacuum the solution of the classical Euclidean equation of motion of the background field is needed. On the other hand radiative corrections have to be taken into account already in the equation of motion. Hence, the latter one has to be the functional derivative of the effective action

V. M. Ruutu, V. B. Eltsov, M. Krusius, Yu. G. Makhlin

We use neutron absorption in rotating 3He-B to heat locally a 10 micrometer-size volume into normal phase. When the heated region cools back in microseconds, vortex lines are formed. We record with NMR the number of lines as a function of superflow velocity and compare to the Kibble-Zurek theory of vortex-loop freeze-out from a random network of defects. The

Tomohiro Harada

A stability analysis of a spherically symmetric star in scalar-tensor theories of gravity is given in terms of the frequencies of quasi-normal modes. The scalar-tensor theories have a scalar field which is related to gravitation. There is an arbitrary function, the so-called coupling function, which determines the strength of the coupling between the gravita

Hong Chen Fu, Ryu Sasaki

A new approach to probability theory based on quantum mechanical and Lie algebraic ideas is proposed and developed. The underlying fact is the observation that the coherent states of the Heisenberg-Weyl, $su(2)$, $su(r+1)$, $su(1,1)$ and $su(r,1)$ algebras in certain symmetric (bosonic) representations give the ``probability amplitudes'' (or the ``sq

T. H. Baker, P. J. Forrester

The Al-Salam & Carlitz polynomials are $q$-generalizations of the classical Hermite polynomials. Multivariable generalizations of these polynomials are introduced via a generating function involving a multivariable hypergeometric function which is the $q$-analogue of the type-$A$ Dunkl integral kernel. An eigenoperator is established for these polynomials an

J. C. Brunelli, A. Das

We give a Lax description for the system of polytropic gas equations. The special structure of the Lax function naturally leads to the two infinite sets of conserved charges associated with this system. We obtain closed form expressions for the conserved charges as well as the generating functions for them. We show how the study of these generating functions

G. F. Helminck, J. W. van de Leur

In this paper we give a geometric description in terms of the Grassmann manifold of Segal and Wilson, of the reduction of the KP hierarchy known as the vector $k$-constrained KP hierarchy. We also show in a geometric way that these hierarchies are equivalent to Krichever's general rational reductions of the KP hierarchy.

R. A. Sharipov

For the equations $y''=P(x,y) + 3Q(x,y)y' + 3R(x,y){y'}^2 + S(x,y){y'}^3$ the problem of equivalence is considered. Some classical results are resumed in order to prepare the background for the study of special subclass of such equations, which arises in the theory of dynamical systems admitting the normal shift.

J. Harnad, Alexander R. Its

The Fredholm determinants of a special class of integral operators K supported on the union of m curve segments in the complex plane are shown to be the tau-functions of an isomonodromic family of meromorphic covariant derivative operators D_l. These have regular singular points at the 2m endpoints of the curve segments and a singular point of Poincare index

L. L. Salcedo

We study how the entropic uncertainty relation for position and momentum conjugate variables is minimized in the subspace of one-dimensional antisymmetric wave functions. Based partially on numerical evidence and partially on analytical results, a conjecture is presented for the sharp bound and for the minimizers. Conjectures are also presented for the corre

R. Vilela Mendes

A quantum scar is a wave function which displays an high intensity in the region of a classical unstable periodic orbit. Saddle scars are states related to the unstable harmonic motions along the stable manifold of a saddle point of the potential. Using a semiclassical method it is shown that, independently of the overall structure of the potential, the loca

Hiroshi Ito, S. E. Koonin, Ryoichi Seki

Spin-polarization response functions are examined for high-energy $(\vec{e},e'\vec{p})$ reaction by computing the full 18 response functions for the proton kinetic energy $T_{p'}=$ 0.515 GeV and 3.179 GeV with an 16O target. The Dirac eikonal formalism is applied to account for the final-state interactions. The formalism is found to yield the respons

Gerald A. Miller

A light front treatment of the nuclear wave function is developed and applied, using the mean field approximation, to infinite nuclear matter. The nuclear mesons are shown to carry about a third of the nuclear plus momentum; but their momentum distribution has support only at for vanishingly small values of the plus momentum, so the mesons do not contribute

V. V. Flambaum, O. K. Vorov

Approximate analytical formulas for the self-consistent renormalization of P,T-odd and P-odd weak nuclear potentials by the residual nucleon-nucleon strong interaction are derived. The contact spin-flip nucleon-nucleon interaction reduces the constant of the P,T-odd potential 1.5 times for the proton and 1.8 times for the neutron. Renormalization of the P-od

H. Beer, P. Mohr, H. Oberhummer, T. Rauscher

Astrophysical neutron capture rates of light and heavy nuclei have been measured and calculated. For the measurements the activation technique was applied at the 3.75 MV Karlsruhe Van de Graaff accelerator, and at the Geel electron linear accelerator (GELINA) the time-of-flight (TOF) method was used. The calculations were performed using direct and compound

Ta Lê Loi, Alexandru Zaharia

Let g:X -> Y be a smooth (i.e. C^\infty differentiable) map between two smooth manifolds. In analogy with the case of complex polynomial functions, we say that y_0 in Y is a typical value of g if there exists an open neighbourhood U of y_0 in Y, such that the restriction g:g^{-1}(U) -> U is a C^\infty trivial fibration. If y_0 in Y is not a typical value of

Hermann Pfitzner, Georg Schluechtermann

We prove that in the setting of operator spaces the result of Davis, Figiel, Johnson and Pelczynski on factoring weakly compact operators holds accordingly. Though not related directly to the main theorem we add a remark on the description of weakly compact subsets in the dual of noncommutative vector valued ${\rm L}_1$.

Robert Judd

We show that the Schreier sets $\mathcal{S}_α\ (α<ω_1)$ satisfy the following dichotomy property. For every hereditary collection $\cf$ of finite subsets of $\N$, either there exists infinite $M=(m_i)_1^{\infty}\subseteq\N$ such that $\cs_α(M)=\{\{m_i:i\in E\}:E\in\cs_α\}\subseteq\cf$, or there exist infinite $M=(m_i)_1^{\infty},N\subseteq\N$ such that $\cf[

Yi-Yen Wu

The weakly-coupled heterotic string is known to have problems of dilaton/moduli stabilization, supersymmetry breaking (by hidden-sector gaugino condensation), gauge coupling unification (or the Newton&#39;s constant), QCD axion, as well as cosmological problems. We study these problems by adopting the viewpoint that they arise mostly due to our limited calcu

S. Bilke, Z. Burda, B. Petersson

We study universality properties of the Weingarten hyper-cubic random surfaces. Since a long time ago the model with a local restriction forbidding surface self-bendings has been thought to be in a different universality class from the unrestricted model defined on the full set of surfaces. We show that both models in fact belong to the same universality cla

H. C. Pauli

The canonical front form Hamiltonian for non-Abelian SU(N) gauge theory in 3+1 dimensions is mapped non-perturbatively on an effective Hamiltonian which acts only in the Fock space of a quark and an antiquark. The approach is based on the novel method of iterated resolvents and on discretized light-cone quantization, driven to the continuum limit. It is free

Ph. Brax, Neil Turok

We propose a stringy mechanism whereby a large hierarchy between symmetry breaking scales is generated. This mechanism is based upon the existence of a fifth dimension compactified on a segment. We focus on a simple supersymmetric model with one massless Higgs field in the 3 of SU(3) and another one in the $\bar 3$ on each four dimensional end-point of the f

N. I. Starkov, N. P. Zotov

We consider the diffractive photoproduction of $π^+π^- , K^+K^- , D^+D^-$ meson pairs with high masses and transverse momenta in the framework of the Söding model. The total and differential cross sections are calculated for these processes. The role of the form factors is stressed.

Mrinal Dasgupta

Results are presented for the leading power-suppressed (1/Q) contributions to shape variables in deep inelastic lepton scattering. These are then combined with available leading order perturbative estimates.

B. A. Li

Based on an effective chiral theory the 10 coefficients of ChPT are predicted. There is no new parameter. The current quark masses, m_η, f_{K}, and f_η are determined too.

Robert Fleischer, Thomas Mannel

Measurements of the combined branching ratios for $B^\pm \to π^\pm K$ and $B_d \to π^\mp K^\pm$ allow interesting constraints on the CKM angle $γ$, the ratio $r \equiv |T&#39;|/|P&#39;|$ of the current-current and penguin operator contributions to $B_d \to π^\mp K^\pm$, and the CP asymmetry in that decay. Present CLEO results for these branching ratios indic

B. -J. Schaefer, H. -J. Pirner

The Heat Kernel Method is applied to the constituent quark model. We calculate the effect of thermal quark fluctuations on the meson action and the resulting quark condensate and pi pi-scattering amplitude at finite temperature. The quarks produce a chiral phase transition only by their effect on the mesonic coupling constants. The s-wave isospin zero pi pi-

V. A. Petrov, A. V. Prokudin

It is established in the paper that experimental data on deeply virtual exclusive electroproduction of $ρ^0$- and $ϕ$-mesons may be described fairly well in the framework of a generalized Regge approach without additional, $Q^2$-dependent, singularities in the J-plane.

Sven Soff, D. Ardouin, C. Spieles, S. A. Bass

We present a new technique for observing the strangelet production in quark matter based on unlike particle correlations. A simulation is presented with a two-phase thermodynamical model.

Frank Cuypers

Ces notes de cours visent a decrire de maniere pedagogique certaines extensions populaires du modele standard des interactions fortes et electrofaibless. Les sujets abordes comprennent le secteur de Higgs, le modele symetrique gauche-droit, la grande unification et la supersymetrie. L&#39;accent est mis sur les consequences phenomenologiques et les methodes

David B. Kaplan

Talk presented at Rencontres de Moriond &#34;Electroweak Interactions and Unified Theories&#34;, March 15-22, 1997, based on work with F. Lepeintre and M. Schmaltz, hep-ph/9705411.

Laura Reina, Giulia Ricciardi, Amarjit Soni

We present a complete calculation of the Leading Order QCD corrections to the quark level decay amplitude for b -> s gamma gamma and study their relevance for both the inclusive branching ratio BR(B -> X_s gamma gamma) and for the exclusive decay channel B_s -> gamma gamma. In addition to the uncertainties in the short distance calculation, due to the choice

J. F. Gunion, R. Vogt

We compute the predictions of intrinsic charm for deep-inelastic scattering at high-Q^2 and compare to HERA data. With the inclusion of constraints from low-energy data, enhancements beyond the predictions of standard structure functions are very modest, but peaking in the leptoquark mass variable is present near 200 GeV. Ultimately, the ability of HERA to p

Sergio Caracciolo, Maria Serena Causo, Andrea Pelissetto

We study three-dimensional self-avoiding walks in presence of a one-dimensional excluded region. We show the appearance of a universal sub-leading exponent which is independent of the particular shape and symmetries of the excluded region. A classical argument provides the estimate: $Δ= 2 ν- 1 \approx 0.175(1)$. The numerical simulation gives $Δ= 0.18(2)$.

Sergio Caracciolo, Maria Serena Causo, Andrea Pelissetto

In this paper we offer some simple and quite general arguments which suggest that the first subleading exponent $Δ$ does not depend on the set of broken symmetries, but only on the dimensionality of the excluded region. An explicit value for this exponent is conjectured. We reserve analytical and numerical details to a forthcoming paper.

D. I. Santiago, D. Kalligas, R. V. Wagoner

We study the cosmological evolution of massless single-field scalar-tensor theories of gravitation from the time before the onset of $e^+e^-$ annihilation and nucleosynthesis up to the present. The cosmological evolution together with the observational bounds on the abundances of the lightest elements (those mostly produced in the early universe) place const

Milan Mijic

A Schroedinger picture analysis of time dependent quantum oscillators, in a manner of Guth and Pi, clearly identifies two physical mechanisms for possible decoherence of vacuum fluctuations in early universe: turning of quantum oscillators upside-down, and rapid squeezing of upside-right oscillators so that certain squeezing factor diverges. In inflationary

Mohammad Nouri-Zonoz

Using the quasi-Maxwell form of the vacuum Einstein equations and demanding the presence of a cylindrically symmetric radial gravomagnetic field, we find the solution to the Einstein equations which represents the gravity field of a line gravomagnetic monopole. We show that this is the generalization of the Levi-Civita&#39;s cylindrically symmetric static sp

A. W. Sandvik, R. R. P. Singh, D. K. Campbell

A quantum Monte Carlo algorithm is constructed starting from the standard perturbation expansion in the interaction representation. The resulting configuration space is strongly related to that of the Stochastic Series Expansion (SSE) method, which is based on a direct power series expansion of exp(-beta*H). Sampling procedures previously developed for the S

D. Shahar, M. Hilke, C. C. Li, D. C. Tsui

This paper describes an experimental identification and characterization of a new low temperature transport regime near the quantum Hall-to-insulator transition. In this regime, a wide range of transport data are compactly described by a simple phenomenological form which, on the one hand, is inconsistent with either quantum Hall or insulating behavior and,

G. Milde, S. Kobe

Exact solutions for the learning problem of autoassociative networks with binary couplings are determined by a new method. The use of a branch-and-bound algorithm leads to a substantial saving of computational time compared with complete enumeration. As a result, fully connected networks with up to 40 neurons could be investigated. The network capacity is fo

D. P. Belanger

New advances in experiments on the random-field Ising model, as realized in dilute antiferromagnets, have brought us much closer to a full characterization of the static and dynamic critical behavior of the unusual phase transition in three dimensions (d=3). The most important experiments that have laid the ground work for our present understanding are revie

B. Eisenblaetter, L. Santen, A. Schadschneider, M. Schreckenberg

The cellular automaton model for traffic flow exhibits a jamming transition from a free-flow phase to a congested phase. In the deterministic case this transition corresponds to a critical point with diverging correlation length. In the presence of noise, however, no consistent picture has emerged up to now. We present data from numerical simulations which s

Ph. Jacquod, D. L. Shepelyansky

We study the level spacing statistics P(s) in many-body Fermi systems and determine a critical two-body interaction strength Uc at which a crossover from Poisson to Wigner-Dyson statistics takes place. Near the Fermi level the results allow to find a critical temperature Tch above which quantum chaos and thermalization set in.

Francesco Sciortino, Linda Fabbian, Sow-Hsin Chen, Piero Tartaglia

In this article we study in detail the Q-vector dependence of the collective dynamics in simulated deeply supercooled SPC/E water. The evolution of the system has been followed for 250 ns at low T, allowing a clear identification of a two step relaxation process. We present evidence in favor of the use of the mode coupling theory for supercooled liquid as fr

Ulf Hermjakob, Raymond J. Mooney

We present a knowledge and context-based system for parsing and translating natural language and evaluate it on sentences from the Wall Street Journal. Applying machine learning techniques, the system uses parse action examples acquired under supervision to generate a deterministic shift-reduce parser in the form of a decision structure. It relies heavily on

E. V. Gotthelf, G. Vasisht

We clarify the nature of the small-diameter supernova remnant (SNR) Kes 73 and its central compact source, 1E 1841-045, using X-ray data acquired with the ASCA Observatory. We introduce a spatio-spectral decomposition technique necessary to disentangle the ASCA spectrum of the compact source from the barely resolved shell-type remnant. The source spectrum (1

Michael B. Christiansen, Norman K. Glendenning

We demonstrate that the form and location (not the size or spacing) of the energetically preferred geometrical structure of the crystalline quark-hadron mixed phase in a neutron star is very sensitive to finite size terms beyond the surface term. We consider two independent approaches of including further finite size terms, namely the multiple reflection exp

P. Saracco, A. Iovino, B. Garilli, D. Maccagni

We present K&#39;-band galaxy counts in the magnitude range $13 < K&#39; < 20$, obtained from two independent surveys near the South Galactic Pole, covering an area of $\sim 40 arcmin^2$ and $\sim 170 arcmin^2$, including $\sim 200$ and $\sim 1000$ objects respectively up to a magnitude limit $K&#39; \sim 20.0$ and $K&#39;\sim 19.0$. At magnitudes $K > 18.5$

Konrad Kuijken

It has been known that recent microlensing results towards the bulge imply mass densities that are surprisingly high given dynamical constraints on the Milky Way mass distribution. We derive the maximum optical depth towards the bulge that may be generated by axisymmetric structures in the Milky Way, and show that observations are close to surpassing these l

K. A. Postnov

Stochastic gravitational waves (GW) associated with unresolved astrophysical sources at frequency bands of the ongoing GW interferometers LIGO/VIRGO and LISA are studied. We show that GW noise from rotating galactic neutron stars with low magnetic fields may reach the advanced LIGO sensitivity level at frequency $f\sim 100$ Hz. Within LISA frequency band (10

M. Heydari-Malayeri, F. Courbin, G. Rauw, O. Esslinger

On the basis of sub-arcsecond optical imaging we resolve and study the core components of the LMC OB association LH 39. The central star of the association, the rare transition object R84, is also investigated using CASPEC echelle spectroscopy. A new, powerful image restoration code that conserves the fluxes allows us to obtain the magnitudes and colors of t

Yutaka Fujita, Junji Fukumoto, Katsuya Okoshi

We present the results of a variety of simulations concerning the evolution of multiphase (inhomogeneous) hot interstellar medium (ISM) in elliptical galaxies. We assume the gases ejected from stars do not mix globally with the circumferential gas. The ejected gas components evolve separately according to their birth time, position, and origin. We consider c

Julia Pryadko, Vahe Petrosian

This paper extends our earlier work on the acceleration of low-energy electrons by plasma turbulence to include the effects of finite temperature of the plasma. We consider the resonant interaction of thermal electrons with the whole transverse branch of plasma waves propagating along the magnetic field. We show that our earlier published results for acceler

Deepto Chakrabarty

Rapid UBVRI photometry of this ultracompact LMXB pulsar has detected 7.67 s optical pulsations in all five bands. The optical pulsations, which are at the same frequency as the X-ray pulsations, are understood as reprocessing of pulsed X-rays in the accretion disk or on the companion surface. The optical pulsed fraction is 6%, independent of wavelength, indi

Deepto Chakrabarty, Paul Roche

We present multiwavelength observations of this S-type symbiotic LMXB which consists of a 2-min X-ray pulsar accreting from an M6 III giant. This is the only symbiotic system definitely known to contain a neutron star. The steady interstellar extinction toward the binary (Av=5) contrasts the variable N_H inferred from X-ray measurements, most likely evidence

Alexander Belopolsky

Geometrical meaning of superstring pictures is discussed in details. An off-shell generalization of the picture changing operation and its inverse are constructed. It is demonstrated that the generalised operations are inverse to each other on-shell while off-shell their product is a projection operator.

Manash Mukherjee, Gunther Karner

We obtain a new characterization for irrational numbers of constant type -- defined as irrationals with bounded partial quotients in their continued fraction expansion. The result is essential in the formulation of stability criteria for orbits of quantum twist maps in a class of dynamical systems.

Ioannis Bakas, Michele Bourdeau, Gabriel Lopes Cardoso

We consider the low-energy effective field theory of heterotic string theory compactified on a seven-torus, and we construct electrically charged as well as more general solitonic solutions. These solutions preserve 1/2, 1/4 and 1/8 of N=8, D=3 supersymmetry and have Killing spinors which exist due to cancellation of holonomies. The associated space-time lin

Igor Halperin, Ariel Zhitnitsky

We argue that a large fraction of the proton spin comes from a contribution due to a nonperturbative intrinsic charm component of the proton. An account of this contribution removes an apparent contradiction between the data and exact Kühn-Zakharov low energy theorem. On the other hand, we show that a large intrinsic charm spin component of the proton is imp

H. J. Bussemaker, A. Deutsch, E. Geigant

A cellular automaton model is presented for random walkers with biologically motivated interactions favoring local alignment and leading to collective motion or swarming behavior. The degree of alignment is controlled by a sensitivity parameter, and a dynamical phase transition exhibiting spontaneous breaking of rotational symmetry occurs at a critical param

S. A. Bludman

Direct observations of the supposedly universal primordial deuterium abundance imply a relatively large baryon density $Ω_B= (0.019-0.030)h^{-2}$ (95% C.L.). On the other hand, concordance between the previously accepted $^4 He$ and $^7 Li$ abundances and standard Big Bang Nucleosynthesis requires the thrice smaller value $Ω_B=(0.005-0.010)h^{-2}$ (95% C.L.)

Paul B. Slater

We study four distinct families of Gibbs canonical distributions defined on the standard complex, quaternionic, real and classical (nonquantum) two-level systems. The structure function or density of states for any two-level system is a simple power (1, 3, 0 or -1) of the length of its polarization vector, while the magnitude of the energy of the system, in

H. J. Bussemaker, T. R. Kirkpatrick

Using an effective-field-theory (nonlinear sigma model) description of interacting electrons in a disordered metal ring enclosing magnetic flux, we calculate the moments of the persistent current distribution, in terms of interacting Goldstone modes (diffusons and cooperons). At the lowest or Gaussian order we reproduce well-known results for the average cur

Albion Lawrence, Nikita Nekrasov

We analyze the vector multiplet prepotential of d=4, N=2 type IIA compactifications. We find that the worldsheet instanton corrections have a natural interpretation as one-loop corrections in five dimensions, with the extra dimension being compactified on a circle of radius $g_{s}\ell_{s}$. We argue that the relation between spacetime and worldsheet instanto

E. I. Chiang, P. Goldreich

We derive hydrostatic, radiative equilibrium models for passive disks surrounding T Tauri stars. Each disk is encased by an optically thin layer of superheated dust grains. This layer re-emits directly to space about half the stellar energy it absorbs. The other half is emitted inward and regulates the interior temperature of the disk. The heated disk flares

M. Kolesik, M. A. Novotny, P. A. Rikvold

Iron sesquilayers grown at room temperature on W(110) exhibit a pronounced coercivity maximum near a coverage of 1.5 atomic monolayers. On lattices which faithfully reproduce the morphology of the real films, a kinetic Ising model is utilized to simulate the domain-wall motion. Simulations reveal that the dynamics is dominated by the second-layer islands, wh

Antonio Dobado, Antonio L. Maroto

In this note we provide a simple explanation of the recent finding of anisotropy in electromagnetic (EM) propagation claimed by Nodland and Ralston (astro-ph/9704196). We consider, as a possible origin of such effect, the effective coupling between EM fields and some tiny background torsion field. The coupling is obtained after integrating out charged fermio

Charles Radin, Lorenzo Sadun

We classify all subgroups of $SO(3)$ that are generated by two elements, each a rotation of finite order, about axes separated by an angle that is a rational multiple of $π$. In all cases we give a presentation of the subgroup. In most cases the subgroup is the free product, or the amalgamated free product, of cyclic groups or dihedral groups. The relations

Paul Benioff

Validation of a presumably universal theory, such as quantum mechanics, requires a quantum mechanical description of systems that carry out theoretical calculations and experiments. The description of quantum computers is under active development. No description of systems to carry out experiments has been given. A small step in this direction is taken here

F. Krüger, L. M. Sehgal

As a sequel to the calculation of the CP-violating asymmetry in the decay rates of b -> d l^+l^- and \bar{b} -> \bar{d} l^+l^-, we address in this paper the asymmetry in exclusive channels \bar{B} -> pi e^+e^- and \bar{B} -> rho e^+e^-, using form factors from two different models. In the invariant mass region 1GeV < \sqrt{s} < M_{J/psi}, the partial width a

J. -P. Kneib, D. Alloin, Y. Mellier, S. Guilloteau

We present a new investigation of the Cloverleaf (z=2.558) based on the combination of archival HST/WFPC2 data, recent IRAM CO(7-6) maps and wide field CFHT/FOCAM images. The deepest WFPC2 observation shows a significant overdensity of I ~ 23--25 galaxies around the Cloverleaf that we interpret as the presence of a cluster of galaxies along the line of sight

Dror Bar-Natan, Stavros Garoufalidis, Lev Rozansky, Dylan P. Thurston

Path integrals don&#39;t really exist, but it is very useful to dream that they do exist, and figure out the consequences. Apart from describing much of the physical world as we now know it, these dreams also lead to some highly non-trivial mathematical theorems and theories. We argue that even though non-trivial flat connections on S^3 don&#39;t really exis

Jens Lieberum

We prove a refinement of Vogel&#39;s statement that the Vassiliev invariants of knots coming from semisimple Lie algebras do not generate all Vassiliev invariants. This refinement takes into account the second grading on Vassiliev invariants induced by cabling of knots. As an application we get an amelioration of the actually known lower bounds for the dimen

Takahiro T. Nakamura, Takahiko Matsubara, Yasushi Suto

The observed two-point correlation functions of galaxies in redshift space become anisotropic due to the geometry of the universe as well as due to the presence of the peculiar velocity field. On the basis of linear perturbation theory, we expand the induced anisotropies of the correlation functions with respect to the redshift $z$, and obtain analytic formu

S. Arnouts, V. de Lapparent, G. Mathez, A. Mazure

We present the photometric sample of a faint galaxy survey carried out in the southern hemisphere, using CCDs on the 3.60m and NTT-3.5m telescopes at La Silla (ESO). The survey area is a continuous strip of 0.2 deg x 1.53 deg located at high galactic latitude (-83 deg) in the Sculptor constellation. The photometric survey provides total magnitudes in the ban

Haye Hinrichsen, Roberto Livi, David Mukamel, Antonio Politi

A simple two dimensional model of a phase growing on a substrate is introduced. The model is characterized by an adsorption rate q, and a desorption rate p. It exhibits a wetting transition which may be viewed as an unbinding transition of an interface from a wall. For p=1, the model may be mapped onto an exactly soluble equilibrium model exhibiting complete

Hideyasu Yamashita

This paper presents some methods of representing canonical commutation relations in terms of hyperfinite-dimensional matrices, which are constructed by nonstandard analysis. The first method uses representations of a nonstandard extension of finite Heisenberg group, called hyperfinite Heisenberg group. The second is based on hyperfinite-dimensional represent

Minoru Wakimoto

In this note we give a new construction of the N=2 superconformal algebra using currents of the affine superalgebra $\hat{sl}(2 | 1)$ and free bosonic fields, and also the N=4 superconformal algebra without central charge in terms of currents of $\hat{sl}(2 | 2)$ and free bosonic fields. Arguments on commutants and invariant subspaces are added.

J. N. Bahcall, P. I. Krastev

We calculate accurately the number of solar neutrino events expected as a function of solar zenith angle, with and without neutrino oscillations, for detectors at the locations of Super-Kamiokande, SNO, and the Gran Sasso National Laboratory. Using different earth models to estimate geophysical uncertainties, and different solar models to estimate solar unce

Ruediger Schack, Carlton M. Caves

Hypersensitivity to perturbation is a criterion for chaos based on the question of how much information about a perturbing environment is needed to keep the entropy of a Hamiltonian system from increasing. In this paper we give a brief overview of our work on hypersensitivity to perturbation in classical and quantum systems.

Gerrit Burgers

Anomalies during an El Nino are dominated by a single, irregularly oscillating, mode. Equatorial dynamics has been linked to delayed-oscillator models of this mode. Usually, the El Nino mode is regarded as an unstable mode of the coupled atmosphere system and the irregularity is attributed to noise and possibly chaos. Here a variation on the delayed oscillat

David G. Madland

We report on our progress in the calculation of nuclear ground-state properties using effective Lagrangians whose construction is constrained by QCD scales and chiral symmetry. Good evidence is found that QCD and chiral symmetry apply to finite nuclei.

V. V. Flambaum, O. K. Vorov

A method to calculate the mean squared matrix element of weak interaction between compound states is developed. The result is expressed in terms of matrix elements of the nucleon-nucleon strong and weak interactions times the Fermi distribution functions at finite temperature. Numerical calculations for $^{233}$Th are in excellent agreement with recent measu

P Papazoglou, D Zschiesche S Schramm, H Stöcker, W Greiner

We investigate the properties of hadronic matter and nuclei be means of a generalized $SU(3)\times SU(3)$ $σ$ model with broken scale invariance. In mean-field approximation, vector and scalar interactions yield a saturating nuclear equation of state. Finite nuclei can be reasonably described, too. The condensates and the effective baryon masses at finite ba

Josef Sollfrank, Pasi Huovinen, P V Ruuskanen

We present a phenomenological model for the initial conditions needed in a one-fluid hydrodynamical description of ultrarelativistic nuclear collisions at CERN--SPS. The basic ingredient is the parametrization of the baryon stopping, i.e. the rapidity distribution, as a function of the thickness of the nuclei. We apply the model to S + S and Pb + Pb collisio

FOPI Collaboration, B. Hong, N. Herrmann, J. L. Ritman

Charged pion spectra measured in 58Ni-58Ni collisions at 1.06, 1.45 and 1.93 AGeV are interpreted in terms of a thermal model including the decay of Delta resonances. The transverse momentum spectra of pions are well reproduced by adding the pions originating from the Delta-resonance decay to the component of thermal pions, deduced from the high transverse m

Joaquin Bustoz, Sergei K. Suslov

We prove orthogonality relations for some analogs of trigonometric functions on a $q$-quadratic grid and introduce the corresponding $q$-Fourier series. We also discuss several other properties of this basic trigonometric system and the $q$-Fourier series.

Vladimir Kanovei

We prove that if $\leq$ is an analytic partial order then either $\leq$ can be extended to a (boldface) $Δ^1_2$ linear order similar to an antichain in $2^{<ω_1}$ ordered lexicographically or a certain Borel partial order $\leq_0$ embeds in $\leq.$ Some corollaries for analytic equivalence relations are given, for instance, if $E$ is a $Σ^1_1[z]$ equivalence

Giovanni Amelino-Camelia, Jerzy Lukierski, Anatol Nowicki

We describe the deformed covariant phase space corresponding to the so-called kappa-deformation of D=4 relativistic symmetries, with quantum ``time&#39;&#39; coordinate and Heisenberg algebra obtained according to the Heisenberg double construction. The associated modified uncertainty relations are analyzed, and in particular it is shown that these relations

Cl. Gabriel, Ph. Spindel, S. Massar, R. Parentani

We compute the transition amplitudes between charged particles of mass $M$ and $m$ accelerated by a constant electric field and interacting by the exchange of quanta of a third field. We work in second quantization in order to take into account both recoil effects induced by transitions and the vacuum instability of the charged fields. In spite of both effec

Ph. Brax, Neil Turok

We investigate the natural occurence of exponentially small couplings in effective field theories deduced from higher dimensional models. We calculate the coupling between twisted fields of the Z_3 Abelian orbifold compactification of the heterotic string. Due to the propagation of massive Kaluza-Klein modes between the fixed points of the orbifold, the mass

Kazuo Fujikawa, Kazumi Okuyama

A Lorentz covariant matrix regularization of membrane thories is studied.It is shown that the action for a bosonic membrane can be defined by matrix regularization in a Lorentz covariant manner. The generator of area preserving diffeomorphism can also be consistently defined by matrix regularization, and we can make the area preserving gauge symmetry manifes

Silas R. Beane

We study a 2N-flavor effective theory of N-flavor QCD. With the axial anomaly accounted for in the effective theory by a &#39;t Hooft interaction, only QCD conserved currents survive. However, there is a residual discrete symmetry with interesting properties. With non-vanishing quark masses, this S_2 symmetry is broken unless \barθ=0 or pi. We further show t

I. Jack, D. R. T. Jones, M. A. Samuel

We present a prediction for the four loop $β$-function for SQCD based on the method of Asymptotic Padé Approximants.

Y. J. Feng, C. S. Lam

The graphical method discussed previously can be used to create new gauges not reachable by the path-integral formalism. By this means a new gauge is designed for more efficient two-loop QCD calculations. It is related to but simpler than the ordinary background-field gauge, in that even the triple-gluon vertices for internal lines contain only four terms, n

Silas R. Beane

We consider the possibility that QCD with N flavors has a useful low-energy description with 2N flavors. Specifically, we investigate a free theory of 2N quarks. Although the free theory is U(N)_L X U(N)_R invariant, it admits a larger U(2N) invariance. However, when the axial anomaly is accounted for in the effective theory by a &#39;t Hooft interaction, on