April 1998 arXiv papers — page 11

Per Bylund, Jaume Gudayol

Given a compact pseudo-metric space, we associate to it upper and lower dimensions, depending only on the metric. Then we construct a doubling metric for which the measure of a dillated ball is closely related to these dimensions.

Siegfried Bosch, Qing Liu

Let A_K be an abelian variety over a discrete valuation field K. Let A be the Neron model of A_K over the ring of integers O_K of K and A_k its special fibre. We study the set of rational points of the group of components ϕ_A of A_k. In particular, we look at the cases where A_K is a Jacobian or where A_K is an abelian variety having semi-stable reduction. W

George Androulakis, Peter G. Casazza, Denka N. Kutzarova

We give new examples of weak Hilbert spaces.

Roman Vershynin

We find a natural class of transformations ("flattened perturbations") of a norming M-basis in a Banach space X, which give a strong norming M-basis in X. This simplifies and generalizes the positive answer to the "strong M-basis problem" solved by P. Terenzi. We also show that in general one cannot achieve uniformly minimality applying stand

Peter G. Casazza, Mark C. Lammers

We show that the classification problem for genus n Banach spaces can be reduced to the unconditionally primary case and that the critical case there is n=2. It is further shown that a genus n Banach space is unconditionally primary if and only if it contains a complemented subspace of genus (n-1). We begin the process of classifying the genus 2 spaces by sh

Haskell P. Rosenthal

This work introduces operator space analogues of the Separable Extension Property (SEP) for Banach spaces; the Complete Separable Extension Property (CSEP) and the Complete Separable Complemention Property (CSCP). The results use the technique of a new proof of Sobczyk's Theorem, which also yields new results for the SEP in the non-separable situation, e

V. Farmaki

A system of uniform families on an infinite subset $M$ of $\nn$ is a collection $(\cca_ξ)_{ξ<ω_1}$ of families of finite subsets of $\nn$ (where, $\cca_k$ consists of all $k$--element subset of $M$, for $k\in \nn$) with the properties that each $\cca_ξ$ is thin (i.e. it does not contain proper initial segments of any of its element) and the Cantor--Bendixson

Boris Dubrovin

Lecture 1. Algebraic properties of correlators in 2D topological field theory. Moduli of a 2D TFT and WDVV equations of associativity. Lecture 2. Equations of associativity and Frobenius manifolds. Deformed flat connection and its monodromy at the origin. Lecture 3. Semisimplicity and canonical coordinates. Lecture 4. Classification of semisimple Frobenius m

Steven Dale Cutkosky

Suppose that X to Y is a generically finite map of nonsingular varieties over a field of characteristic zero, and v is a valuation of the function field of X. We prove that it is possible to perform a sequence of monoidal transforms X&#39; to X and Y&#39; to Y so that X&#39; to Y&#39; is a monomial mapping at the center of v. We deduce from this that a birat

Renata Kallosh, Antoine Van Proeyen

We show that the background field method applied to supergravity in adS space-time provides the path integral for the theory in the bulk with conformal symmetry associated with the isometry of the adS space. This in turn allows to establish the rigid conformal invariance of the generating functional for the supergravity correlators on the boundary.

C. G. Carvalhaes, L. V. Belvedere, R. L. P. G. do Amaral, N. A. Lemos

A foundational investigation of the basic structural properties of two-dimensional anomalous gauge theories is performed. The Hilbert space is constructed as the representation of the intrinsic local field algebra generated by the fundamental set of field operators whose Wightman functions define the model. We examine the effect of the use of a redundant fie

Karim Benakli

We provide the first example of a cosmological solution of the Horava-Witten supergravity. This solution is obtained by exchanging the role of time with the radial coordinate of the transverse space to the five-brane soliton. On the boundary this corresponds to rotating an instanton solution into a tunneling process in a space with Lorentzian signature, lead

E. Sharpe

In this paper we conjecture a reformulation of the monomial-divisor mirror map for (2,2) mirror symmetry, valid at a boundary of the moduli space, that is easily extended to also include tangent bundle deformations -- an important step towards understanding (0,2) mirror symmetry. We check our conjecture in a few simple cases, and thereby illustrate how to pe

J. C. Peng, G. T. Garvey, T. C. Awes, M. E. Beddo

The Drell-Yan cross section ratios, $σ(p+d)/σ(p+p)$, measured in Fermilab E866, have led to the first determination of $\bar d(x) / \bar u(x)$, $\bar d(x) - \bar u(x)$, and the integral of $\bar d(x) - \bar u(x)$ for the proton over the range $0.02 \le x \le 0.345$. The E866 results are compared with predictions based on parton distribution functions and var

S. Keller

In this contribution I briefly summarize several topics related to the measurement of the W-boson mass, M_W, at hadron colliders.

P. Piwnicki, S. P. Klevansky, P. Rehberg

The transition amplitude for $πK$ scattering is evaluated within the SU(3) Nambu--Jona-Lasinio model. Ordering terms according to the expansion in $1/N_c$ leads to a box-like diagram, $t$ channel diagrams that admit scalar isoscalar $(σ,σ&#39;)$ exchanges, and a $u$ channel exchange of a scalar isodoublet $σ_K$ that has quantum numbers corresponding to the $

S. F. King, M. Oliveira

Lepton flavour violation has been proposed as a significant test of supersymmetric unification. Here we show that such signals are also a generic feature of supersymmetric string unified models in which there is no simple unified gauge group. In realistic models of this kind which involve third family Yukawa unification and large values of $\tan β$, there ar

H. Meyer-Ortmanns, T. Reisz

Dynamical linked cluster expansions are linked cluster expansions with hopping parameter terms endowed with their own dynamics. This amounts to a generalization from 2-point to point-link-point interactions. We develop an associated graph theory with a generalized notion of connectivity and describe an algorithmic generation of the new multiple-line graphs.

Andrew R Liddle, Anne M Green

Primordial black holes may form in the early Universe, for example from the collapse of large amplitude density perturbations predicted in some inflationary models. Light black holes undergo Hawking evaporation, the energy injection from which is constrained both at the epoch of nucleosynthesis and at the present. The failure as yet to unambiguously detect p

A. Garrett Lisi

This paper shows how to obtain the spinor field and dynamics from the vielbein and geometry of General Relativity. The spinor field is physically realized as an orthogonal transformation of the vielbein, and the spinor action enters as the requirement that the unit time form be the gradient of a scalar time field.

Pablo A. Venegas, Edson Sardella

We investigate the flux penetration patterns and matching fields of a long cylindrical wire of circular cross section in the presence of an external magnetic field. For this study we write the London theory for a long cylinder both for the mixed and Meissner state, with boundary conditions appropriate for this geometry. Using the Monte Carlo Simulated Anneal

Th. M. Nieuwenhuizen, C. N. A. van Duin

In realistic spinglasses, such as CuMn, AuFe and EuSrS, magnetic atoms are located at random positions. Their couplings are determined by their relative positions. For such systems a field theory is formulated. In certain limits it reduces to the Hopfield model, the Sherrington-Kirkpatrick model, and the Viana-Bray model. The model has a percolation transiti

R. A. Broglia, G. Tiana, S. Pasquali, H. E. Roman

Studies of how protein fold have shown that the way protein clumps form in the test tube is similar to how proteins form the so-called ``amyloid&#39;&#39; deposits that are the pathological signal of a variety of diseases, among them the memory disorder Alzheimer&#39;s. Protein aggregation have traditionally been connected to either unfolded or native states

M. C. W. van Rossum, Th. M. Nieuwenhuizen

A tutorial discussion of the propagation of waves in random media is presented. In first approximation the transport of the multiple scattered waves is given by diffusion theory, but important corrections are present. These corrections are calculated with the radiative transfer or Schwarzschild-Milne equation, which describes intensity transport at the ``mes

Reimer Kuehn, Uta Horstmann

We review a model--based rather than phenomenological approach to low--temperature anomalies in glasses. Specifically, we present a solvable model inspired by spin--glass theory that exhibits both, a glassy low--temperature phase, and a collection of double-- and single--well configurations in its potential energy landscape. The distribution of parameters ch

Krzysztof Rosciszewski, Klaus Doll, Beate Paulus, Peter Fulde

Electron-correlation effects on cohesive energy, lattice constant and bulk compressibility of rutile are calculated using an ab-initio scheme. A competition between the two groups of partially covalent Ti-O bonds is the reason that the correlation energy does not change linearly with deviations from the equilibrium geometry, but is dominated by quadratic ter

D. S. Hall, M. R. Matthews, J. R. Ensher, C. E. Wieman

We present studies of the time-evolution of a two-component system of Bose-Einstein condensates (BEC) in the |F=1, mf=-1> and |2,1> spin states of Rb-87. The two condensates are created with a well-defined relative phase and complete spatial overlap. In subsequent evolution they undergo complex relative motions which tend to preserve the total density profil

K. Anagnostopoulos, P. Bialas, G. Thorleifsson

We study with Monte Carlo methods an ensemble of c=-5 gravity graphs, generated by coupling a conformal field theory with central charge c=-5 to two-dimensional quantum gravity. We measure the fractal properties of the ensemble, such as the string susceptibility exponent gamma_s and the intrinsic fractal dimensions d_H. We find gamma_s = -1.5(1) and d_H = 3.

M. Alava, H. Rieger

The sensitivity of the random field Ising model to small random perturbations of the quenched disorder is studied via exact ground states obtained with a maximum-flow algorithm. In one and two space dimensions we find a mild form of chaos, meaning that the overlap of the old, unperturbed ground state and the new one is smaller than one, but extensive. In thr

J. C. Woo, W. S. Kim, H. S. Ko, Y. A. Leem

In Zeeman spectra of a GaAs-AlGaAs quantum wire array with superlattice period lp, the zero-field shift is found to increase in steps of (2 pi hbar/ e)lp^{-2} at the cyclotron radius Rc ~lp, lp/2, and lp/3. This shift, caused by spin-Landau orbit coupling and quantized in units of the flux quantum 2 pi hbar /e,is a manifestation of the gauge invariance, and

Jean-Sebastien Caux

We present a nonperturbative calculation of all multifractal scaling exponents at strong disorder for critical wavefunctions of Dirac fermions interacting with a non-Abelian random vector potential in two dimensions. The results, valid for an arbitrary number of fermionic flavours, are obtained by deriving from Conformal Field Theory an effective Gaussian mo

Bertrand Berche, Pierre Emmanuel Berche, Ferenc Iglói, Gábor Palágyi

We consider a system with randomly layered ferromagnetic bonds (McCoy-Wu model) and study its critical properties in the frame of mean-field theory. In the low-temperature phase there is an average spontaneous magnetization in the system, which vanishes as a power law at the critical point with the critical exponents $β\approx 3.6$ and $β_1 \approx 4.1$ in t

Shiyi Chen, Ciprian Foias, Darryl D. Holm, Eric Olson

We propose the viscous Camassa-Holm equations as a closure approximation for the Reynolds-averaged equations of the incompressible Navier-Stokes fluid. This approximation is tested on turbulent channel flows with steady mean. Analytical solutions for the mean velocity and the Reynolds shear stress across the entire channel are obtained, showing good agreemen

R. Moderski, M. Sikora, J. -P. Lasota

We investigate whether models based on the assumption that jets in quasars are powered by rotating black holes can explain the observed radio dichotomy of quasars. We show that in terms of the ``spin paradigm&#39;&#39; models, radio-loud quasars could be objects in which the black hole&#39;s rotation rate corresponds to an equilibrium between spin-up by accr

P. de Bernardis, S. Masi

We review the topic of Cosmic Microwave Background Anisotropy measurements carried out by means of balloon-borne telescopes. After a short description of the experimental methodology, we outline the peculiar problems of these experiments, and we describe the main results obtained and the perspects for future developments.

A. Bottino, F. Donato, N. Fornengo, P. Salati

We analyze the data of low-energy cosmic-ray antiproton spectrum, recently published by the BESS Collaboration, in terms of newly calculated fluxes for secondary antiprotons and for a possible contribution of an exotic signal due to neutralino annihilation in the galactic halo. We single out the relevant supersymmetric configurations and discuss their explor

K. Nandra, J. Clavel, R. A. Edelson, I. M. George

We have undertaken near-continuous monitoring of the Seyfert 1 galaxy NGC 7469 in the X-ray with RXTE over a ~30d baseline. The source shows strong variability with a root-mean-square (rms) amplitude of ~16 per cent, and peak-to-peak variations of a factor of order 2. Simultaneous data over this period were obtained in the ultraviolet (UV) using IUE, making

Alexander Kusenko

Acoustic shock waves passing through colliding cold neutron stars can cause repetitive superconducting phase transitions in which the proton condensate relaxes to its equilibrium value via coherent oscillations. As a result, a resonant non-thermal production of gamma rays in the MeV energy range with power up to 10^(52) erg/s can take place during the short

S. Le Bohec, B. Degrange, M. Punch, A. Barrau

A new method of shower-image analysis is presented which appears very powerful as applied to those Cherenkov Imaging Telescopes with very high definition imaging capability. It provides hadron rejection on the basis of a single cut on the image shape, and simultaneously determines the energy of the electromagnetic shower and the position of the shower axis w

Maximilian Ruffert, H. -Thomas Janka

Three-dimensional hydrodynamical simulations are presented for the direct head-on or off-center collision of two neutron stars, employing a basically Newtonian PPM code but including the emission of gravitational waves and their back-reaction on the hydrodynamical flow. A physical nuclear equation of state is used that allows us to follow the thermodynamical

Y. Sobouti, V. Rezania

We use the post Newtonian (pn) order of Liouville&#39;s equation (pnl) to study the normal modes of oscillation of a relativistic system. In addition to classical modes, we are able to isolate a new class of oscillations that arise from perturbations of the space-time metric. In the first pn order; a) their frequency is an order q smaller than the classical

Robert Schmidt, Joachim Wambsganss

The light curves of the two images of the double quasar Q0957+561 as obtained by Kundic et al. (1997) are almost identical, except for an overall time delay and scaling factor. This allows us to put limits on the amount of microlensing that took place during the time interval corresponding to the monitoring observations. We perform numerical simulations in w

David W. Hogg, Judith G. Cohen, Roger Blandford, Michael A. Pahre

Equivalent widths of [OII] 3727 A lines are measured in 375 faint galaxy spectra taken as part of the Caltech Faint Galaxy Redshift Survey centered on the Hubble Deep Field. The sensitivity of the survey spectra to the [OII] line is computed as a function of magnitude, color and redshift. The luminosity function of galaxies in the [OII] line and the integrat

Mariano Mendez, Tomaso Belloni, Michiel van der Klis

We analyze RXTE/PCA observations of the black hole candidate and galactic superluminal source GRO J1655-40 during its recent outburst. We show that during its decay to quiescence, GRO J1655-40 goes through the high, intermediate, and low state (and that at the beginning of its decay it might have even shown signatures of a very high state), just like other b

Mirek Giersz

A revision of Stodolkiewicz&#39;s Monte-Carlo code is used to simulate evolution of star clusters. The new method treats each superstar as a single star and follows the evolution and motion of all individual stellar objects. The first calculations for isolated, equal-mass N-body systems with three-body energy generation according to Spitzer&#39;s formulae sh

Yasushi Suto, Tetsu Kitayama, Shin Sasaki

Cosmological implications of clusters of galaxies are discussed with particular attention to their importance in probing the cosmological parameters. More specifically we compute the number counts of clusters of galaxies, Log $N$ -- Log $S$ relation, in X-ray and submm bands on the basis of the Press--Schechter theory. We pay particular attention to a set of

S. Y. Sazonov, R. A. Sunyaev

It has been recently realized (Rephaeli 1995) that the relativistic corrections to the spectral distortions of the cosmic microwave background (CMB) measured in the direction of clusters of galaxies containing hot gas are significant and should be detectable with the forthcoming experiments. In the present paper we calculate the correction terms that are pro

Zurab Kakushadze, Gary Shiu, S. -H. Henry Tye

We consider six and four dimensional ${\cal N}=1$ supersymmetric orientifolds of Type IIB compactified on orbifolds. We give the conditions under which the perturbative world-sheet orientifold approach is adequate, and list the four dimensional ${\cal N}=1$ orientifolds (which are rather constrained) that satisfy these conditions. We argue that in most cases

Victor M. Yakovenko, Hsi-Sheng Goan

We derive the effective action for a moving magnetic-field-induced spin-density wave (FISDW) in quasi-one-dimensional conductors at zero and nonzero temperatures by taking the functional integral over the electron field. The effective action consists of the (2+1)D Chern-Simons term and the (1+1)D chiral anomaly term, both written for a sum of the electromagn

Mike Bisset, Otto C. W. Kong, Cosmin Macesanu, Lynne H. Orr

We present a parametrization of the supersymmetric standard model without R-parity that permits efficient phenomenological analyses of the full model without a priori assumptions. Under the parametrization, which is characterized by a single vacuum expectation value for the scalar components of the Y=-1/2 superfields, the expressions for tree-level mass matr

Maxim Olshanii

We calculate, within the pseudopotential approximation, a one-dimensional scattering amplitude and effective one-dimensional interaction potential for atoms confined transversally by an atom waveguide or highly elongated ``cigar&#39;&#39;-shaped atomic trap. We show that in the low-energy scattering regime, the scattering process degenerates to a total refle

Hong Liu, A. A. Tseytlin

We consider the role of N=4 conformal supergravity in the relation between N=4 SYM theory and D=5 gauged supergravity expanded near the Anti de Sitter background. We discuss the structure of the SYM effective action in conformal supergravity background, in particular, terms related to conformal anomaly. Solving the leading-order Dirichlet problem for the met

John F. Donoghue, Barry R. Holstein, Bugra Borasoy

The use of SU(3) chiral perturbation theory in the analysis of low energy meson-baryon interactions is discussed. It is emphasized that short distance effects, arising from propagation of Goldstone bosons over distances smaller than a typical hadronic size, are model-dependent and can lead to a lack of convergence in the SU(3) chiral expansion if they are in

Andrew DeBenedictis

The renormalised value of $<ϕ^2>$ is calculated for a massless, conformally coupled scalar field in the Hartle-Hawking vacuum state. This calculation is a first step towards the calculation of the gravitational back reaction of the field in a black cosmic string spacetime which is asymptotically anti-DeSitter and possesses a non constant dilaton field. It is

Jens O. Andersen

Dimensional reduction and effective field theory methods are applied to the Two Higgs Doublet Model at finite temperature. A sequence of two effective three-dimensional field theories which are valid on successively longer distance scales is constructed. The resulting Lagrangian can be used to study different aspects of the phase transition in this model as

Pushan Majumdar, H. S. Sharatchandra

The problem of Wu-Yang ambiguities in 3 dimensions is related to the problem of existence of torsion free driebeins for an arbitrary potential. The ambiguity is only at the level of boundary conditions. We also find that in 3 dimensions any smooth Yang-Mills field tensor can be uniquely written as the non-Abelian magnetic field of a smooth Yang-Mills potenti

P. Meszaros, M. J. Rees

Gamma ray burst outflows may entrain small blobs or filaments of dense, highly ionized metal rich material. Such inhomogeneities, accelerated by the flow to Lorentz factors in the range 10-100, could have a significant coverage factor, and give rise to broad features, especially due to Fe K-edges, which influence the spectrum below the MeV range, leading to

Ting-Wai Chiu

The square root of the positive definite hermitian operator $D_w^{\dagger} D_w$ in Neuberger&#39;s proposal of exactly massless quarks on the lattice is implemented by the recursion formula $Y_{k+1} = {1/2} (Y_k + D_w^{\dagger} D_w Y_k^{-1})$ with $Y_0 = \Id$, where $Y_k^2$ converges to $D_w^{\dagger} D_w$ quadratically. The spectrum of the lattice Dirac ope

Yuichi Chikira, Naoyuki Haba, Yukihiro Mimura

The sliding singlet mechanism is one of the most interesting solutions of the triplet-doublet splitting problem. We analyze this mechanism in the gauge mediated supersymmetry breaking scenario. We show that the sliding singlet mechanism does not work in the naive gauge mediation scenario because of the singlet linear terms derived from the gravity, although

O. B. Zaslavskii

New approach to exact solvability of dilaton gravity theories is suggested which appeals directly to structure of field equations. It is shown that black holes regular at the horizon are static and their metric is found explicitly. If a metric possesses singularities the whole spacetime can be divided into different sheets with one horizon on each sheet betw

Shervgi S. Shahverdiyev, I. V. Tyutin

The existence of a local solution to the Sp(2) master equation for gauge field theory is proven in the framework of perturbation theory and under standard assumptions on regularity of the action. The arbitrariness of solutions to the Sp(2) master equation is described, provided that they are proper. It is also shown that the effective action can be chosen to

A. N. Leznov

The problem of construction of irreducible representations of quantum $A^q_n$ algebras is solved at the level of explicit integration of the linear (inhomogeneous) system in finite differences in the n-dimensional space. The general solution of this system is given explicitly and particular ones, which correspond to the irreducible representations are select

Vladislav G. Bagrov, Boris F. Samsonov, L. A. Shekoyan

N-order Darboux transformation operator is defined on the basis of a general notion of transformation operators. Factorisation properties of this operator are studied. The Darboux transformation operator technique is applied to construct and investigate potentials with bound states at arbitrary energies for the spectral problem on semiaxis.

N. Mosyagin, M. Kozlov, A. Titov

Calculations of transition energies between low-lying states of mercury atom are performed in the frame of combined CI/MBPT2 method. Results of all-electron relativistic calculations (using the Dirac-Coulomb Hamiltonian) are compared with experimental data and results of other four-component calculations. The results of the RECP calculations are compared wit

A. Akmal, V. R. Pandharipande, D. G. Ravenhall

Properties of dense nucleon matter and the structure of neutron stars are studied using variational chain summation methods and the new Argonne v18 two-nucleon interaction. The neutron star gravitational mass limit obtained with this interaction is 1.67 M_{solar}. Boost corrections to the two-nucleon interaction, which give the leading relativistic effect of

T. D. Palev

The Holstein-Primakoff and the Dyson realizations of the Lie superalgebra $gl(n/m)$ are generalized to the class of the quantum superalgebras $U_q[gl(n/m)]$ for any $n$ and $m$. It is shown how the elements of $U_q[gl(n/m)]$ can be expressed via $n-1$ pairs of Bose creation and annihilation operators and $m$ pairs of Fermi creation and annihilation operators

O. B. Zaslavskii

A. Ghosh and P. Mitra made the proposal how to explain the area law for the entropy of extreme black holes in some model calculations. I argue that their approach implicitly operates with strongly singular geometries and says nothing about the contribution of regular metrics of extreme black holes into the partition function.

Machiko Hatsuda, Kiyoshi Kamimura

We present Wess-Zumino actions for general IIA D-p-branes in explicit forms. We perform the covariant and irreducible separation of the fermionic constraints of IIA D-p-branes into the first class and the second class. A necessary condition which guarantees this separation is discussed. The generators of the local supersymmetry (kappa symmetry) and the kappa

Z. Guralnik

We find aspects of electrically confining large $N$ Yang-Mills theories on $T^2 \times R^{d-2}$ which are consistent with a $GL(2,Z)$ duality. The modular parameter associated with this $GL(2,Z)$ is given by ${m\over N} + iΛ^2 A$, where $A$ is the area of the torus, $m$ is the t&#39;Hooft twist on the torus, and $Λ^2$ is the string tension. $N$ is taken to i

Seungwon Baek, J. S. Shim, H. S. Song, Chaehyun Yu

It is shown that the transition amplitudes of radiative electroweak processes like $e^-e^+ \to ν_e \olν_e \ga$, $\ga e^- \to ν_e \olν_e e^-$, and $ν_e e^- \to ν_e e^- \ga$ can be reduced and factorized into simpler forms in the Standard Model. This method can be used in reducing many calculations of complicated radiative electroweak processes in general.

J. W. Negele

An elementary introduction is presented to the study of hadron structure using lattice QCD. Following a brief review of relevant aspects of path integrals, the discrete lattice path integral is presented for gluon and quark fields and used to calculate physical observables. Essential aspects of instanton physics are reviewed, and it is shown how the instanto

Gilvan Alves

We present the first results of detector R & D done for the proposed Forward Proton Detector at D0. From a menu of options we have chosen a scintillating fiber based detector with multi-anode photomultiplier readout.

Wu Zhong Chao

If one introduces causality into quantum cosmology, then the prescription for the no-boundary universe should be revised. We show that the thermodymanic arrow of time associated with the perturbation modes should be reversed at the maximum expansion for the oscillating Hawking model. To an observer equipped with the time arrow, the universe will terminate it

Joerg Schmalian, David Pines, Branko Stojkovic

We derive in detail a novel solution of the spin fermion model which is valid in the quasi-static limit pi T<<omega_sf, found in the intermediate (pseudoscaling) regime of the magnetic phase diagram of cuprate superconductors, and use it to obtain results for the temperature and doping dependence of the single particle spectral density, the electron-spin flu

Martin Greiner, Hans C. Eggers, Peter Lipa

We have found an analytic expression for the multivariate generating function governing all n-point statistics of random multiplicative cascade processes. The variable appropriate for this generating function is the logarithm of the energy density, ln epsilon, rather than epsilon itself. All cumulant statistics become sums over derivatives of ``branching gen

Virgil Baran, Aldo Bonasera

The asymptotic distance between trajectories $d_{\infty}$, is studied in detail to characterize the occurrence of chaos. We show that this quantity is quite distinct and complementary to the Lyapunov exponents, and it allows for a quantitave estimate for the folding mechanism which keeps the motion bounded in phase space. We study the behaviour of $d_{\infty

P. A. Yecko, Z. Kollath, J. R. Buchler

A one-dimensional turbulent convection model in the form of a time-dependent diffusion equation for the turbulent energy is incorporated into our numerical pulsation code. The effect of turbulent convection on the structural rearrangement of the static equilibrium star is taken into account, and the linear eigenvalues (periods and growth-rates) for the compl

P. Tozzi

The X-ray emission from clusters of galaxies is one of the most pursued observational probe to investigate the distribution of dark matter and the related density parameter Omega0. The crucial link to derive the statistics of observables from a dynamical theory is constituted by the physics for the diffuse baryons (or ICP) responsible of the X-ray emission.

Luca Zampieri, Monica Colpi, Stuart L. Shapiro, Ira Wasserman

We present the first fully relativistic investigation of matter fallback in a supernova. We investigate spherically symmetric supernova fallback using a relativistic radiation hydrodynamics Lagrangian code that handles radiation transport in all regimes. Our goal is to answer the fundamental question: did SN1987A produce a black hole and, if so, when will th

F. Combes

Galaxy evolution depends strongly on the environment. Dynamical interactions and subsequent evolution make galaxies more concentrated, with higher surface densities, and also trigger star-formation, which consumes the available cold gas. Already at z=0, a large variety of galaxy types are observed, with different evolution stages, from the unevolved gas rich

Masaaki Sakano, Katsuji Koyama, Takeshi Tsuru, Hisamitsu Awaki

We present results of ASCA deep exposure observations of the hardest X-ray source discovered in the ASCA Large Sky Survey (LSS) project, designated as AX J131501+3141. We extract its accurate X-ray spectrum, taking account of the contamination from a nearby soft source (AX J131502+3142), separated only by 1&#39;. AX J131501+3141 exhibits a large absorption o

Anthony G. A. Brown, Fredrick M. Walter, Adriaan Blaauw

We review the current knowledge of the population of `older&#39; stars in the Orion OB1 association, specifically those in subgroups 1a and 1b. We briefly outline the history of the subject and then continue with a summary of the present state of knowledge of the early-type stars in Orion OB1. New results from the Hipparcos parallaxes and proper motions will

B. Dutta, R. N. Mohapatra

It has recently shown that in supersymmetric left-right models with automatic R-parity conservation, the theory below the $W_R$ scale is given by MSSM with massive neutrinos and a pair of doubly charged superfields with masses in the 100 GeV range (with or without an extra pair of heavy Higgs doublets (M \geq 10 TeV) depending on the model). In this paper we

Juan Maldacena, Andrew Strominger

The duality relating near-horizon microstates of black holes obtained as orbifolds of a subset of AdS3 to the states of a conformal field theory is analyzed in detail. The SL(2,R) invariant vacuum on AdS3 corresponds to the NS-NS vacuum of the conformal field theory. The effect of the orbifolding is to produce a density matrix, the temperature and entropy of

A. H. Vartanian

Using the matrix Riemann-Hilbert factorisation approach for non-linear evolution systems which take the form of Lax-pair isospectral deformations, the higher order asymptotics as $t \to \pm \infty$ $(x/t \sim {\cal O}(1))$ of the solution to the Cauchy problem for the modified non-linear Schrödinger equation, $i \partial_{t} u + {1/2} \partial_{x}^{2} u + |

Asher Peres, Daniel Terno

Given a finite set of linearly independent quantum states, an observer who examines a single quantum system may sometimes identify its state with certainty. However, unless these quantum states are orthogonal, there is a finite probability of failure. A complete solution is given to the problem of optimal distinction of three states, having arbitrary prior p

Costas Efthimiou

This paper offers a solution method that allows one to find exact values for a large class of convergent series of rational terms. Sums of this form arise often in problems dealing with Quantum Field Theory.

Yukihiro Okuno, Kazumasa Miyake

The weak antiferromagnetism of URu${}_{2}$Si${}_{2}$ is discussed on the basis of a duality model which takes into account salient features of both itinerant fermions and &#34;localized&#34; component of spin degrees of freedom. The problem is analyzed in the framework of induced-moment mechanism by taking a singlet-singlet crystal field scheme together with

Paul R. Shapiro, Alejandro C. Raga, Garrelt Mellema

The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other primordial gas-clouds and photoevaporating them. Results are presented of the first gas dynamical simulations of this process, including radiative transfer, along with some observational diag

Gordon Baym

In the 1950&#39;s Hanbury Brown and Twiss showed that one could measure the angular sizes of astronomical radio sources and stars from correlations of signal intensities, rather than amplitudes, in independent detectors. Their subsequent correlation experiments demonstrating quantum bunching of photons in incoherent light beams were seminal in the developmen

A. Strumia

We compute the two-loop corrections to the coefficient of the b --> s gamma magnetic penguin present in the limits of heavy top and/or heavy higgs. This kind of corrections affects in a significant way the observables measured at LEP. On the contrary we find that, due to a numerical accident, the correction to BR(B --> X_s gamma) is negligible (below the 1%

M. Mangin-Brinet, J. Carbonell, C. Gignoux

Exact boundary conditions at finite distance for the solutions of the time-dependent Schrodinger equation are derived. A numerical scheme based on Crank-Nicholson method is proposed to illustrate its applicability in several examples.

Akira Shimizu, Masamichi Yamanishi

We consider generation of an electrical pulse by an optical pulse in the ``virtual excitation&#39;&#39; regime. The electronic system, which is any electro-optic material including a quantum well structure biased by a dc electric field, is assumed to be coupled to an external circuit. It is found that the photon frequency is subject to an extra red shift in

Akira Shimizu, Teruaki Okushima, Kazuki Koshino

Using microscopic models in which both photons and excitons are treated as microscopic degrees of freedom, we discuss polaritons of two cases: One is the case when excitonic parameters are time dependent. The time dependence causes creation of polaritons from a &#34;false vacuum.&#34; % We present the creation spectra of both % the lower- and upper-branch po

Akira Shimizu

Measurement and fluctuations are closely related to each other in quantum mechanics. This fact is explicitly demonstrated in the case of a quantum non-demolition photodetector which is composed of a double quantum-wire electron interferometer.

Daniel C. Cohen, Alexander I. Suciu

The k-th Fitting ideal of the Alexander invariant B of an arrangement A of n complex hyperplanes defines a characteristic subvariety, V_k(A), of the complex algebraic n-torus. In the combinatorially determined case where B decomposes as a direct sum of local Alexander invariants, we obtain a complete description of V_k(A). For any arrangement A, we show that

John Ellis, N. E. Mavromatos, D. V. Nanopoulos

We first review the interpretation of world-sheet defects as $D$ branes described by a critical theory in 11 dimensions, that we interpret as $M$ theory. We then show that $D$-brane recoil induces dynamically an anti-de-Sitter (AdS) space-time background, with criticality restored by a twelfth time-like dimension described by a Liouville field. Local physics

K. Zarembo

Background field method is used to perform renormalization group transformations for Schrödinger equation in QCD. The dependence of the ground state wave functional on rapidly oscillating fields is found.

A. B. Arbuzov, E. A. Kuraev, F. F. Tikhonin, B. G. Shaikhatdenov

QED radiative corrections to the cross-section of muon-antimuon annihilation into Higgs boson and photon are calculated within the 1-loop approximation. We write down the expression for cross-section in the form of Drell-Yan process, taking into account higher order leading logs. The non-singlet structure functions of fermions are shown to obey here evolutio

Wolfgang Bock, Maarten F. L. Golterman, Yigal Shamir

We review the status of our recent work on the gauge-fixing approach to lattice chiral gauge theories. New numerical results in the reduced version of a model with a U(1) gauge symmetry are presented which strongly indicate that the factorization of the correlation functions of the left-handed neutral and right-handed charged fermion fields, which we establi