January 1999 arXiv papers — page 4

L. Prado,

Nucleon form factors are evaluated in the spacelike region in a light-front framework. Our phenomenological model is based on a relativistic formulation of the Hamiltonian dynamics. The baryon dynamics is solved in the CMS with relativistic kinetic energy, linearly rising confining potential and a residual interaction based on instanton-induced forces, the s

W. C. Haxton

These lectures cover three topics in neutrino astrophysics. The solar neutrino problem is reviewed, with particular emphasis on the microphysics of the standard solar model, detector responses, the quantum mechanics of the MSW mechanism, and the possibility of spin-flavor oscillations. In the second lecture the electromagnetic properties of Dirac and Majoran

R. Benton Metcalf, Joseph Silk

Dark matter may consist of weakly interacting elementary particles or of macroscopic compact objects. We show that the statistics of the gravitational lensing of high redshift supernovae strongly discriminate between these two classes of dark matter candidates. We develop a method of calculating the magnification distribution of supernovae, which can be inte

N. Dorey, T. J. Hollowood, V. V. Khoze, M. P. Mattis

We present a self-contained study of ADHM multi-instantons in SU(N) gauge theory, especially the novel interplay with supersymmetry and the large-N limit. We give both field- and string-theoretic derivations of the N=4 supersymmetric multi-instanton action and collective coordinate integration measure. As a central application, we focus on certain n-point fu

N. Gisin, S. Popescu

We consider two different ways to encode quantum information, by parallel or anti-parallel pairs of spins. We find that there is more information in the anti-parallel ones. This purely quantum mechanical effect is due to entanglement, not of the states but occuring in the course of the measuring process. We also introduce a range of quantum information proce

B. G. Sidharth

We throw further light on a recently discussed Kerr-Newman type formulation of Fermions and the related cosmological scheme which predicted an ever expanding universe, as indeed has subsequently been confirmed. In the spirit of the correspondence principle, it is shown how the quark picture emerges at the Compton wavelength and the Big Bang scenario at the P

Martin Konopka, Vladimir Buzek

We propose a method for entangling a system of two-level atoms in photonic crystals. The atoms are assumed to move in void regions of a photonic crystal. The interaction between the atoms is mediated either via a defect mode or via resonant dipole-dipole interaction. We show that these interactions can produce pure entangled atomic states. We analyze the pro

Christof Zalka

I investigate whether it would technologically and economically make sense to build database search engines based on Grover's quantum search algorithm. The answer is not fully conclusive but in my judgement rather negative.

Hendry I. Elim

An exact solution of the energy shift in each quantum mechanical energy levels in a one dimensional symmetrical linear harmonic oscillator has been investigated. The solution we have used here is firstly derived by manipulating Schrodinger differential equation to be confluent hypergeometric differential equation. The final exact numerical results of the ene

Igor P. Omelyan

It is shown that the dielectric properties of interaction site models of polar fluids can be investigated in computer experiment using not only the charge fluctuations but also correlations corresponding to a current of moving charges. This current can be associated with a generalized dynamical polarization or separated into electric and magnetic components.

Timur Zh. Esirkepov

As an alternative to solving of Poisson equation in Particle-in-Cell methods, a new construction of current density exactly satisfying continuity equation in finite differences is developed. This procedure called density decomposition is proved to be the only possible linear procedure for defining the current density associated with the motion of a particle.

S. G. Arutunian, N. M. Dobrovolski, M. R. Mailian, I. G. Sinenko

The method for measurement of transverse profile (emittance) of the bunch by detecting of radiation arising scattering at of the bunch on the scanning wire is wide-spread. In this work the information about scattering bunch is proposed to measure using the oscillation frequency of the tightened scanning wire. In such way the system of radiation (or secondary

Z. K. Silagadze

A curious observation was made that the rank statistics of scientific citation numbers follows Zipf-Mandelbrot's law. The same pow-like behavior is exhibited by some simple random citation models. The observed regularity indicates not so much the peculiar character of the underlying (complex) process, but more likely, than it is usually assumed, its more

Robert J. Perry

Light-front quantum chromodynamics may lead to an accurate constituent approximation for the low-energy properties of hadrons. This requires a cutoff that violates explicit gauge invariance and Lorentz covariance, leading to the calculation of a renormalized QCD hamiltonian using a similarity renormalization group. Renormalization repairs broken symmetries,

Robert J. Perry, Sergio Szpigel

The Schrodinger equation with a two-dimensional delta-function potential is a simple example of an asymptotically free theory that undergoes dimensional transmutation. Renormalization requires the introduction of a mass scale, which can be lowered perturbatively until an infrared cutoff produced by non-perturbative effects such as bound state formation is en

Thomas Strohmer

A shift-invariant system is a collection of functions $\{g_{m,n}\}$ of the form $g_{m,n}(k) = g_m(k-an)$. Such systems play an important role in time-frequency analysis and digital signal processing. A principal problem is to find a dual system $γ_{m,n}(k) = γ_m(k-an)$ such that each function $f$ can be written as $f = \sum < f, γ_{m,n} > g_{m,n}$. The mathe

Otmar Scherzer, Thomas Strohmer

We study numerical methods for the solution of general linear moment problems, where the solution belongs to a family of nested subspaces of a Hilbert space. Multi-level algorithms, based on the conjugate gradient method and the Landweber--Richardson method are proposed that determine the &#34;optimal&#34; reconstruction level a posteriori from quantities th

Martin Lorenz

Let G be a finite group acting by automorphism on a lattice A, and hence on the group algebra S=k[A]. The algebra of G-invariants in S is called an algebra of multiplicative invariants. We investigate when algebras of multiplicative invariants are semigroup algebras. In particular, we present an explicit version of a result of Farkas stating that multiplicat

Jinho Baik, Percy Deift, Kurt Johansson

We investigate the probability distribution of the length of the second row of a Young diagram of size $N$ equipped with Plancherel measure. We obtain an expression for the generating function of the distribution in terms of a derivative of an associated Fredholm determinant, which can then be used to show that as $N\to\infty$ the distribution converges to t

Peter W. Michor, Izu Vaisman

A class of n-ary Poisson structures of constant rank is indicated. Then, one proves that the ternary Poisson brackets are exactly those which are defined by a decomposable 3-vector field. The key point is the proof of a lemma which tells that an n-vector $(n\geq3)$ is decomposable iff all its contractions with up to n-2 covectors are decomposable.

A. O. Prishlyak

Theorems on the existence of vector fields with given sets of Indexes of isolated Singular points are proved for the cases of closed manifolds, pairs of manifolds, manifolds with boundary, and gradient fields. It is proved that, on a two-dimensional manifold, an index of an isolated Singular point of the gradient field is not greater than one.

A. O. Prishlyak

A theorem on the existence of the unique minimal topologic handle decomposition of differentiable simply connected five-dimensional manifolds is proved. For a decomposition of this sort, the number of handles of each index is given.

Fritz Gesztesy, Konstantin A. Makarov, Serguei N. Naboko

We introduce the concept of a spectral shift operator and use it to derive Krein&#39;s spectral shift function for pairs of self-adjoint operators. Our principal tools are operator-valued Herglotz functions and their logarithms. Applications to Krein&#39;s trace formula and to the Birman-Solomyak spectral averaging formula are discussed.

Rugang Ye

We construct equivariant and Bott-type Seiberg-Witten Floer homology and cohomology for 3-manifolds, in particular rational homology spheres, and prove their diffeomorphism invariance. We present several versions of the equivariant theory: the singular version, the de Rham version and the Cartan version, with the first playing the most important role. These

Guofang Wang, Rugang Ye

We construct Bott-type and equivariant Seiberg-Witten Floer homology and cohomology for 3-manifolds, in particular rational homology spheres, and prove their diffeomorphism invariance. This paper is a revised version of math.DG/9701010. Some typos are removed.

Holger Guenther, Carl Herrmann, Jan Louis

Quantum corrections in the hypermultiplet moduli space of type IIA string theories compactified on Calabi-Yau threefolds are investigated.

Ofer Aharony, Jacek Pawelczyk, Stefan Theisen, Shimon Yankielowicz

We test the AdS/CFT correspondence in the case of a d=4 N=2 SCFT by comparing chiral anomalies which are of order N in the &#39;t Hooft large N limit. These include corrections of order 1/N to the conformal anomaly, thus testing the correspondence beyond the extreme large N limit. The field theory anomalies are reproduced by terms in the 7-brane effective ac

Jorge Ananias Neto, Emanuel R. de Oliveira, Wilson Oliveira

The SU(2) collective coordinates quantization of the Born-Infeld Skyrmions Lagrangean is performed. The obtainment of the classical Hamiltonian from this special Lagrangean is made by using an approximate way: it is derived from the expansion of this non-polynomial Lagrangean up to second-order variable in the collective coordinates, using for this some caus

Ian Kogan, Oleg Soloviev

We propose a world-sheet realization of the zigzag-invariant strings as a perturbed WZNW model at large negative level. We argue that the gravitational dressing produces additional fixed points of the dressed renormalization beta function. One of these new critical points can be interpreted as a zigzag-invariant string model.

Viqar Husain

We describe a class of diffeomorphism invariant SU(N) gauge theories in N^2 dimensions, together with some matter couplings. These theories have (N^2-3)(N^2-1) local degrees of freedom, and have the unusual feature that the constraint associated with time reparametrizations is identically satisfied. A related class of SU(N) theories in N^2-1 dimensions has t

M. Cvetic, H. Lu, C. N. Pope, T. A Tran

We obtain the closed-form absorption probabilities for minimally-coupled massless scalars propagating in the background of D=5 single-charge and D=4 two-charge black holes. These are the only two examples of extremal black holes with non-vanishing absorption probabilities that can be solved in closed form for arbitrary incident frequencies. In both cases, th

Jesús Puente Peñalba

The principle of equivalence is translated into the language of the world-volume field theories that define matrix and string theories. This idea leads to explore possible matrix descriptions of M-theory compactifications. An interesting case is the relationship between D=6 N=1 U(M) SYM and Matrix Theory on K3.

S. Ying

It is found that, in addition to the conventional ones, a local approach to the relativistic quantum field theories at both zero and finite density consistent with the violation of Bell like inequalities should contain, and provide solutions to at least three additional problems, namely, 1) the statistical gauge invariance 2) the dark components of the local

J. Balla, M. V. Polyakov, C. Weiss

The spin-dependent twist-3 and 4 nucleon matrix elements d^(2) and f^(2) describing power corrections to the Bjorken and Ellis-Jaffe sum rules are computed in the instanton vacuum. A systematic expansion in the small packing fraction of the instanton medium, rho / R << 1, is performed. We find that the twist-3 matrix element d^(2) is suppressed [of order (rh

A. Ioannisian, G. Raffelt

We discuss the Cherenkov process $ν\toνγ$ in the presence of a homogeneous magnetic field. The neutrinos are taken to be massless with only standard-model couplings. The magnetic field fulfills the dual purpose of inducing an effective neutrino-photon vertex and of modifying the photon dispersion relation such that the Cherenkov condition $ω<|{\bf k}|$ is fu

A. Ioannisian

We discuss $ν- γ$ interactions in the presence of a homogeneous magnetic field with energies less than pair production threshold. The neutrinos are taken to be massless with only standard-model couplings. The magnetic field fulfills the dual purpose of inducing an effective neutrino-photon vertexes and of modifying the photon dispersion relation. Our conclus

G. I. Smirnov

Nucleon structure function ratios r(x) = F2A(x)/F2D(x) measured in the range of atomic masses A larger or equal 4 are analyzed with the aim to determine the pattern of the x and A dependence of F2(x) modifications caused by nuclear environment. It is found that the x and A dependence of the deviations of the r(x) from unity can be factorized in the entire ra

A. N. Mitra

This article aims at an integrated formulation of BSE&#39;s for 2- and 3-quark hadrons under the Markov-Yukawa Transversality Principle (MYTP) which provides a deep interconnection between the 3D and 4D BSE forms, and hence offers a unified treatment of 3D spectroscopy with 4D quark-loop integrals for hadronic transitions. For the actual dynamics, an NJL-typ

A. D. Martin, M. G. Ryskin, T. Teubner

We estimate the cross section for gamma p -> Upsilon p by two independent methods. First, by studying the corrections to the naive leading-order QCD formula and, second, by using parton-hadron duality. The estimates are in good agreement with each other and with the recent measurements of the cross section at HERA.

Jonathan M. Butterworth, Valery A. Khoze, Wolfgang Ochs

The intensity of the soft bremsstrahlung depends on the colour charges of the hard- scattered partons. This intensity is larger in dijet production with resolved photons by the factor C_A/C_F=9/4 in comparison with direct photoproduction for particular configurations. It is investigated how these effects are reflected in Monte Carlo models.

P. Checchia, E. Piotto, F. Simonetto

The hypothesis of a real Cabibbo-Kobayashi-Maskawa matrix has been considered and found to be disfavoured by present measurements even when neglecting results from CP violation in neutral Kaon decay. This result contradicts statements reported in hep-ph/9810333.

E. Gotsman, E. Levin, U. Maor

We present a two channel eikonal calculation in which the rescattering through a diffractive channel is included in addition to the elastic channel. Considering the spread of the experimental data, we find that we can obtain a very good description of $\s_{tot}$, $\s_{el}$ and $B_{el}$ in the ISR - Tevatron energy range. In this range of energy the diffracti

K. R. Nasriddinov, B. N. Kuranov, T. A. Merkulova

The τ\to ω,ϕπ^- ν_τdecays of the τlepton are studied using the method of phenomenological SU(3) * SU(3) chiral Lagrangians. It is shown that the obtained value for the τ\to ϕπν_τdecay probability is very sensitive to deviations from the mixing angle. Calculated partial widths for these decays are compared with the available experimental and theoretical data.

Andrzej J. Buras

A non-technical description of the Operator Product Expansion and Renormalization Group techniques as applied to weak decays of mesons is presented. We use this opportunity to summarize briefly the present status of the next-to-leading QCD corrections to weak decays and their implications for the unitarity triangle, the ratio epsilon prime/epsilon, the radia

Jinghua Fu, Lianshou Liu, Yuanfang Wu

It is shown that an event sample from the Monte Carlo simulation of a random cascading αmodel with fixed dynamical fluctuation strength is intermittent but not chaotic, while the variance of dynamical fluctuation strength in different events will result in both the intermittency and the chaotic behavior. This shows that fractality and chaoticity are two conn

J. I. Silva-Marcos

We give a new mechanism for generating very small, and almost degenerate, neutrino masses, without resorting to the see-saw mechanism or unnatural small Yukawa couplings. It requires the existence of at least 4 families with an almost democratic structure for the Yukawa couplings. It is also proven that this structure can account for large lepton mixings of

J. Boucrot

The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the $\bd$ meson oscillation frequency is $\dmd =

Serge Droz, Daniel J. Knapp, Eric Poisson, Benjamin J. Owen

We prove that the oft-used stationary-phase method gives a very accurate expression for the Fourier transform of the gravitational-wave signal produced by an inspiraling compact binary. We give three arguments. First, we analytically calculate the next-order correction to the stationary-phase approximation, and show that it is small. This calculation is esse

Jolien D. E. Creighton

In order to analyze data produced by the kilometer-scale gravitational wave detectors that will begin operation early next century, one needs to develop robust statistical tools capable of extracting weak signals from the detector noise. This noise will likely have non-stationary and non-Gaussian components. To facilitate the construction of robust detection

L. H. Ford, Thomas A. Roman

Although quantum field theory allows local negative energy densities and fluxes, it also places severe restrictions upon the magnitude and extent of the negative energy. The restrictions take the form of quantum inequalities. These inequalities imply that a pulse of negative energy must not only be followed by a compensating pulse of positive energy, but tha

Songrit Maneewongvatana, David M. Mount

We present an empirical analysis of data structures for approximate nearest neighbor searching. We compare the well-known optimized kd-tree splitting method against two alternative splitting methods. The first, called the sliding-midpoint method, which attempts to balance the goals of producing subdivision cells of bounded aspect ratio, while not producing a

Shimon Levit, Dror Orgad

We study the statistics of quasiparticle and quasihole levels in small interacting disordered systems within the Hartree-Fock approximation. The distribution of the inverse compressibility, given according to Koopmans&#39; theorem by the distance between the two levels across the Fermi energy, evolves from a Wigner distribution in the non-interacting limit t

L. Brey, E. Demler, S. Das Sarma

We make a number of precise experimental predictions for observing the various magnetic phases and the quantum phase transitions between them in the $ν$=2 bilayer quantum Ha ll system. In particular, we analyze the effect of an external bias voltage on the quantum phase diagram, finding that a finite bias should readily enable the experimental observation of

S. W. Pierson, M. Friesen, S. M. Ammirata, J. C. Hunnicutt

The value of the dynamic critical exponent $z$ is studied for two-dimensional superconducting, superfluid, and Josephson Junction array systems in zero magnetic field via the Fisher-Fisher-Huse dynamic scaling. We find $z\simeq5.6\pm0.3$, a relatively large value indicative of non-diffusive dynamics. Universality of the scaling function is tested and confirm

A. V. Balatsky, P. Bourges

It is shown that the momentum space width of the peak in the spin susceptibility, Im$χ(q,ω)$, is linearly proportional to the superconducting $T_c$: $T_c = \hbar v^*Δq$ with $\hbar v^* \simeq 35 meV$Å. This relation is similar to the linear relation between incommensurate peak splitting and $T_c$ in LaSrCuO superconductors, as first proposed by Yamada et al.

A. Maritan, M. P. Riva, A. Trovato

Exact bounds are obtained for the quenched free energy of a polymer with random hydrophobicities in the presence of an interface separating a polar from a non polar solvent. The polymer may be ideal or have steric self-interactions. The bounds allow to prove that a ``neutral&#39;&#39; random polymer is localized near the interface at any temperature, whereas

M. Cristina Marchetti, David R. Nelson

Patterned irradiation of cuprate superconductors with columnar defects allows a new generation of experiments which can probe the properties of vortex liquids by confining them to controlled geometries. Here we show that an analysis of such experiments that combines an inhomogeneous Bose glass scaling theory with the hydrodynamic description of viscous flow

W. Wernsdorfer, T. Ohm, C. Sangregorio, R. Sessoli

Below 360 mK, Fe magnetic molecular clusters are in the pure quantum relaxation regime and we show that the predicted square-root time relaxation is obeyed, allowing us to develop a new method for watching the evolution of the distribution of molecular spin states in the sample. We measure as a function of applied field H the statistical distribution P(ξ_H)

J. K. Freericks, Ch. Gruber, N. Macris

The simplest statistical-mechanical model of crystalline formation (or alloy formation) that includes electronic degrees of freedom is solved exactly in the limit of large spatial dimensions and infinite interaction strength. The solutions contain both second-order phase transitions and first-order phase transitions (that involve phase-separation or segregat

S. M. Chitanvis

We have advanced our previous static theory of polymer entanglement involving an extended Cahn-Hilliard functional, to include time-dependent dynamics. We go beyond the Gaussian approximation, to the one-loop level, to compute the frequency dependent storage and loss moduli of the system. The three parameters in our theory are obtained by fitting to availabl

Yshai Avishai, Daniel Berend, Richard Berkovits

Fluctuation of Coulomb blockade peak spacings in large two-dimensional semiconductor quantum dots are studied within a model based on the electrostatics of several electron islands among which there are random inductive and capacitive couplings. Each island can accommodate electrons on quantum orbitals whose energies depend also on an external magnetic field

Peter Markos

Distribution of the conductance P(g) at the critical point of the metal-insulator transition is presented for three and four dimensional orthogonal systems. The form of the distribution is discussed. Dimension dependence of P(g) is proven. The limiting cases $g\to\infty$ and $g\to 0$ are discussed in detail and relation $P(g)\to 0$ in the limit $g\to 0$ is p

Pere Colet, Daniel Walgraef, Maxi San Miguel

We study the nature of the instability of the homogeneous steady states of the subcritical Ginzburg-Landau equation in the presence of group velocity. The shift of the absolute instability threshold of the trivial steady state, induced by the destabilizing cubic nonlinearities, is confirmed by the numerical analysis of the evolution of its perturbations. It

R. M. L. Evans

The width of the distribution of species in a polydisperse system is employed in a small-variable expansion, to obtain a well-controlled and compact scheme by which to calculate phase equilibria in multi-phase systems. General and universal relations are derived, which determine the partitioning of the fluid components among the phases. The analysis applies

A. Mourachkine

We present electron-tunneling spectroscopy of slightly overdoped Bi2212 single crystals at low temperature using a break-junction technique. Below Tc, we observe, at least, two different superconducting gaps. We show that (i) the largest superconducting gap occurs due to pairing of spinons; (ii) the second superconducting gap has the d-wave symmetry; (iii) t

W. Wonneberger

Quasi one-dimensional conductors which undergo a Peierls transition to a charge density wave state at a temperature T_P show a region of one-dimensional fluctuations above T_P. The Ginzburg-Landau-Langevin theory for the frequency dependent collective conductivity from conductive fluctuations into the charge density wave state is developed. By inclusion of a

Marco Rosa-Clot, Stefano Taddei

We discuss two numerical methods, based on a path integral approach described in a previous paper (I), for solving the stochastic equations underlying the financial markets: the Monte Carlo approach, and the Green function deterministic numerical method. Then, we apply the latter to some specific financial problems. In particular, we consider the pricing of

A. Kadigrobov, R. I. Shekhter, M. Jonson, Z. Ivanov

Giant oscillations of the conductance of a superconductor - ferromagnet - superconductor Andreev interferometer are predicted. The effect is due to the resonant transmission of normal electrons through Andreev levels when the voltage $V$ applied to the ferromagnet is close to $2h_0/e$ ($h_0$ is the spin-dependant part of the electron energy). The effect of b

Marco Rosa-Clot, Stefano Taddei

We use a path integral approach for solving the stochastic equations underlying the financial markets, and we show the equivalence between the path integral and the usual SDE and PDE methods. We analyze both the one-dimensional and the multi-dimensional cases, with point dependent drift and volatility, and describe a covariant formulation which allows genera

F. Simmel, David Abusch-Magder, D. A. Wharam, M. A. Kastner

We present an experimental study of the fluctuations of Coulomb blockade peak positions of a quantum dot. The dot is defined by patterning the two-dimensional electron gas of a silicon MOSFET structure using stacked gates. This permits variation of the number of electrons on the quantum dot without significant shape distortion. The ratio of charging energy t

Sibel P. Bayrakci, Ophelia K. C. Tsui, N. P. Ong, K. Kishio

The dependence of the Josephson plasma frequency omega_p in Bi_2Sr_2CaCu_2O_8 on a tilted field H is reported. Measurements over a large range of B and tilt angle theta allow a detailed comparison with a recent calculation by Koshelev. With a slight modification of the model, close agreement is obtained. From the fits, we find values for the in-plane correla

T. Kapitaniak, K. Zyczkowski, U. Feudel, C. Grebogi

There exist measuring devices where an analog input is converted into a digital output. Such converters can have a nonlinear internal dynamics. We show how measurements with such converting devices can be understood using concepts from symbolic dynamics. Our approach is based on a nonlinear one-to-one mapping between the analog input and the digital output o

James S. Ulvestad

Supermassive black holes, with masses of 10^6 to more than 10^9 solar masses, are among the most spectacular objects in the Universe, and are laboratories for physics in extreme conditions. The primary goal of ARISE (Advanced Radio Interferometry between Space and Earth) is to use the technique of Space VLBI to increase our understanding of black holes and t

N. Prantzos

Nuclear gamma-ray lines constitute the most genuine diagnostic tool of nuclear astrophysics, since they allow for an unambiguous identification of isotopic species. Continuous improvement in instrumentation led to the discovery of several radioactive species in the past 15 years (Al26, Co56, Co57, Ti44) in various astrophysical sites (SN1987A and SN1991T, Ca

E. V. Gotthelf, R. Petre, G. Vasisht

A new ASCA observation of 1E 161348-5055, the central compact X-ray source in the supernova remnant RCW 103, reveals an order-of-magnitude decrease in its 3 - 10 keV flux since the previous ASCA measurement four years earlier. This result is hard to reconcile with suggestions that the bulk of the emission is simple quasi-blackbody, cooling radiation from an

Christopher F. McKee

Giant molecular clouds (GMCs) are the sites of star formation in the Galaxy. Many of their properties can be understood in terms of a model in which the GMCs and the star-forming clumps within them are in approximate pressure equilibrium, with turbulent motions treated as a separate pressure component.

J. G. Cohen

Spectra with a high signal-to-noise ratio of 79 stars which are just below the main sequence turnoff of M71 are presented. They yield indices for the strength of the G band of CH and the ultraviolet CN band at 3885 Å. These indices are each to first order bimodal and they are anti-correlated. There are approximately equal numbers of CN weak/CH strong and CN

J. G. Cohen

Spectra with a high signal-to-noise ratio of 50 stars which are just below the main sequence turnoff and are members of M13 are presented. They yield indices for the strength of the CH and the ultraviolet CN band. There is no evidence for a variation in the strength of either feature from star to star in this intermediate-metallicity galactic globular cluste

D. L. Khokhlov

Scenario of baryogenesis is considered in which primordial plasma starting from the Planck scale consists of primordial particles being the precursors of electrons and clusters of particles being the precursors of protons. Equilibrium between the precursors of protons and the precursors of electrons is defined by the proton-electron mass difference. At the t

Alexander K. Konopelko

Arrays of imaging air Cherenkov telescopes (IACTs) like VERITAS, HESS have been recently proposed as the instruments of the next generation for ground based very high energy gamma-ray astronomy invading into 50-100 GeV energy range. Here we present results of design studies for the future IACT arrays which have been performed by means of Monte Carlo simulati

R. Fabbri, S. Cortiglioni, S. Cecchini, M. Orsini

We present the cosmological and astrophysical objectives of the SPOrt mission, which is scheduled for flying on the International Space Station (ISS) in the year 2002 with the purpose of measuring the diffuse sky polarized radiation in the microwave region. We discuss the problem of disentangling the cosmic background polarized signal from the Galactic foreg

S. Cortiglioni, S. Cecchini, E. Carretti, M. Orsini

The Sky Polarization Observatory (SPOrt) is presented as a project aimed to measure the diffuse sky polarized emission, from the International Space Station, in the frequency range 20-90 GHz with 7 degrees of HPBW. The SPOrt experimental configuration is described with emphasis on the aspects that make SPOrt the first European scientific payload operating at

Rob Ivison, Ian Smail, Andrew Blain, Jean-Paul Kneib

We discuss observations of the submm-selected galaxy, SMM J02399-0136, and what has been learnt about it during the year following its discovery. SMM J02399-0136 was the first distant galaxy detected in submm surveys with SCUBA. Its association with a massive, gas-rich starburst/AGN at z=2.8 has lead to suggestions that the prevalence of AGN in the early Uni

A. Fontana, S. D&#39;Odorico, R. Fosbury, E. Giallongo

We present the deep UBVRI observations of the HDF-S NICMOS field obtained as part of the Science Verification of the VLT Unit 1 telescope. The images have been used to construct object catalogs and to obtain photometric redshifts. The effective field of view is $\simeq 70\times70$ arcsec$^2$, and the formal $5σ$ limiting magnitudes (in a 2 FWHM aperture) are

Ue-Li Pen

Recent indications of a neutrino mass raise the possibility that the dark matter may be hot, which would be a severe challenge for structure formation theory. We argue that generic defect theories fare very well in hot dark matter cosmologies, and also work in the presence of curvature or a cosmological constant. If this model is correct, then the MAP and PL

Jonathan E. Grindlay

Cataclysmic variables (CVs) are tracers of dynamical evolution in globular clusters. A significant sample has been found by the relatively shallow \Halpha surveys conducted with HST thus far in just three globulars: NGC 6397 (3), NGC 6752 (2), and $ω$-Cen (2). These are identified with the low luminosity x-ray sources discovered in these globulars with simil

Katrin Becker, Melanie Becker

We analyze the hypermultiplet moduli space describing the universal sector of type IIA theory compactified on a Calabi-Yau threefold. The classical moduli space is described in terms of the coset $SU(2,1)/U(2)$. The flux quantization condition of the antisymmetric tensor field of M-theory implies discrete identifications for the scalar fields describing this

Michael Binger, Chueng-Ryong Ji

We have developed a quantum field theoretic framework for scalar and pseudoscalar meson mixing and oscillations in time. The unitary inequivalence of the Fock space of base (unmixed) eigenstates and the physical mixed eigenstates is proven and shown to lead to a rich condensate structure. This is exploited to develop formulas for two flavor boson oscillation

S. Deser, R. Jackiw

We study the higher-derivative extensions of the D=3 Abelian Chern--Simons topological invariant that would appear in a perturbative effective action&#39;s momentum expansion. The leading, third-derivative, extension I_ECS turns out to be unique. It remains parity-odd but depends only on the field strength, hence no longer carries large gauge information, no

W. Hwang, P. L. Krapivsky, S. Redner

We study the dynamics of an age-structured population in which the life expectancy of an offspring may be mutated with respect to that of its parent. When advantageous mutation is favored, the average fitness of the population grows linearly with time $t$, while in the opposite case the average fitness is constant. For no mutational bias, the average fitness

I. P. Ennes, S. G. Naculich, H. Rhedin, H. J. Schnitzer

One-instanton predictions for the prepotential are obtained from the Seiberg-Witten curve for the Coulomb branch of N=2 supersymmetric gauge theory for the product group \prod_{n=1}^{m} SU(N_n) with a massless matter hypermultiplet in the bifundamental representation (N_n,\bar N_{n+1}) of SU(N_n) x SU(N_{n+1}) for n=1 to m-1, together with N_0 and N_{m+1} ma

Thomas B. Schroeder, Srikanth Sastry, Jeppe C. Dyre, Sharon C. Glotzer

An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this ``inherent dynamics&#39;&#39; approach we find direct numerical evidence for the long held view that below a crossover temperature, $T

C. Wexler, G. G. Dussel

A simple parametrization for the octupole collective variables is proposed and the symmetries of the wave functions are discussed in terms of the solutions corresponding to the vibrational limit. [PACS: 21.60Ev, 21.60.Fw, 21.10.Re]

Dylan P. Thurston

It has been folklore for several years in the knot theory community that certain integrals on configuration space, originally motivated by perturbation theory for the Chern-Simons field theory, converge and yield knot invariants. This was proposed independently by Gaudagnini, Martellini, and Mintchev and Bar-Natan. The analytic difficulties involved in provi

Ph. de Forcrand, M. D&#39;Elia

In a numerical experiment, we remove center vortices from an ensemble of lattice SU(2) gauge configurations. This removal adds short-range disorder. Nevertheless, we observe long-range order in the modified ensemble: confinement is lost and chiral symmetry is restored (together with trivial topology), proving that center vortices are responsible for both phe

Sonia Stanciu

We study the possible D-brane configurations in an AdS_3 x S^3 x T^4 background with a NS-NS B field. We use its WZW model description and the boundary state formalism, and we analyze the bosonic and the N=1 supersymmetric cases separately. We also discuss the corresponding classical open string sigma model. We determine the spacetime supersymmetry preserved

G. Arutyunov, S. Frolov

We compute the 3-point function of the stress-energy tensor in the d-dimensional CFT from the AdS_{d+1} gravity. For d=4 the coefficients of the three linearly independent conformally covariant forms entering the 3-point function are exactly the same as given by the free field computations in the ${\cal N}=4$ SYM just as expected from the known renormalizati

R. Escribano, J. M. Frere

A phenomenological analysis on various decay processes is performed using an energy-dependent $η-η&#39;$ mixing angle scheme. Special attention is given to the radiative couplings between lowest-lying vector and pseudoscalar mesons. The agreement between our predictions and the experimental values is remarkable. This analysis opens a connection to two-angle

E. Lisi, Subir Sarkar, F. L. Villante

Recently we presented a simple method for determining the correlated uncertainties of the light element abundances expected from big bang nucleosynthesis, which avoids the need for lengthy Monte Carlo simulations. We now extend this approach to consider departures from the Standard Model, in particular to constrain any new light degrees of freedom present in

Y. Umemoto, S. Hirenzaki, K. Kume

We have developed a phenomenological quasi-deuteron model to describe photodisintegration reactions of $^3$He and $^4$He at intermediate photon energies, and compared the results with experimental data obtained by TAGX group in which contributions from photon absorption by $pn$ pair were selectively observed. The data can be reproduced reasonably well, howev