January 2001 arXiv papers — page 25

David Siegel, Erik Talvila

For continuous boundary data, including data of polynomial growth, modified Poisson integrals are used to write solutions to the half space Dirichlet and Neumann problems in $\mathbb{R}^{n}$. Pointwise growth estimates for these integrals are given and the estimates are proved sharp in a strong sense. For decaying data, a new type of modified Poisson integra

Do Ngoc Diep

The so called quantized algebras of functions on affine Hecke algebras of type A and the corresponding q-Schur algebras are defined and their irreducible unitarizable representations are classified.

Peter A. Loeb, Erik Talvila

This paper shows how the Lebesgue integral can be obtained as a Riemann sum and provides an extension of the Morse Covering Theorem to open sets. Let $X$ be a finite dimensional normed space; let $μ$ be a Radon measure on $X$ and let $Ω\subseteq X$ be a $μ$-measurable set. For $λ\geq1$, a $μ$-measurable set $S_λ(a)\subseteq X$ is a $λ$-Morse set with tag $a\

Erik Talvila

The Riemann-Lebesgue Lemma says that the Fourier transform of an absolutely integrable function on the real line tends to zero as the transform parameter tends to infinity. When the integral is allowed to converge conditionally, the transform can have arbitrarily rapid pointwise growth as the transform parameter tends to infinity. Smoothness of the function

Erik Talvila

We give necessary and sufficient conditions for differentiating under the integral sign an integral that depends on a parameter. The conditions require the equality of two iterated integrals and depend on being able to integrate every derivative. The Henstock integral is thus used in an essential way.

Erik Talvila

Some divergent trigonometric integrals have appeared in standard tables for many years, listed as converging. We give a simple proof that these integrals diverge and trace their history. The original error was made when a (startlingly) famous mathematician incorrectly differentiated under the integral sign with some convergent integrals that depend on a para

Malgorzata Rowicka-Kudlicka

We consider quantum group theory on the Hilbert space level. We find all unitary representations of three braided quantum groups related to the quantum ``ax+b'' group. First we introduce an auxiliary braided quantum group, which is apparently not related to the quantum ``ax+b'' group, but easy to work with. We find all unitary representations

Reinhard Oehme

Superconvergence relations for the transverse gauge field propagator can be used in order to show that the corresponding gauge quanta are not elements of the physical state space, as defined by the BRST algebra. With a given gauge group, these relations are valid for a limited region in the number of matter fields, indicating a phase transition at the bounda

Naresh Dadhich, S. G. Ghosh

We first obtain the analogue of Vaidya's solution on the brane for studying the collapse of null fluid onto a flat Minkowski cavity on the brane. Since the back-reaction of the bulk onto the brane is supposed to strengthen gravity on the brane, it would favour formation of black hole as against naked singularity. That is the parameter window in the initi

J. Bogaerts, A. Sevrin, J. Troost, W. Troost

We probe the effective worldvolume theory of a set of coinciding D-branes by switching on constant electro-magnetic fields on them. The comparison of the mass spectrum predicted by string theory with the mass spectrum obtained from the effective action provides insights in the structure of the effective theory.

Aida X. El-Khadra, Andreas S. Kronfeld, Paul B. Mackenzie, Sinead M. Ryan

We present a lattice QCD calculation of the form factors and differential decay rates for semileptonic decays of the heavy-light mesons $B$ and $D$ to the final state $πlν$. The results are obtained with three methodological improvements over previous lattice calculations: a matching procedure that reduces heavy-quark lattice artifacts, the first study of la

M. M. Block, F. Halzen

Using an eikonal analysis, we simultaneously fit a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, together with cosmic ray data (using Glauber theory), to predict proton-air and proton-proton cross sections at energies near \sqrt s \approx 30 TeV. The p-air cosmic ray measurements g

R. Arnowitt, B. Dutta, Y. Santoso

We consider the neutralino proton cross section for detection of Milky Way dark matter for a number of supergravity models with gauge unification at the GUT scale: models with universal soft breaking (mSUGRA), models with nonuniversal soft breaking, and string inspired D-brane models. The parameter space examined includes m_{1/2}<1 TeV and tan β< 50, and the

J. D. Vergados

The detection of the theoretically expected dark matter is central to particle physics and cosmology. Current fashionable supersymmetric models provide a natural dark matter candidate which is the lightest supersymmetric particle (LSP). The allowed parameter space of such models combined with fairly well understood physics (quark substructure of the nucleon

I. Zborovsky

The formation length of particles produced in the relativistic collisions of hadrons and nuclei has relevance to fundamental principles of physics at small interaction distances. The relation is expressed by z scaling observed in the differential cross sections for the inclusive reactions at high energies. The scaling variable reflects the length of the elem

K. Fialkowski

A rewiew of the development of formalism to describe correlations and fluctuations in multiparticle production is presented. The milestones of history of this development and some obvious sources of correlations in experimental data are recalled. Some recent subjects concerning the correlations are shortly discussed.

Hans Peter Nilles

Although the cosmological constant has primarily cosmological consequences, its smallness poses one of the basic problems in particle physics. Various attempts have been made to explain this mystery, but no satisfactory solution has been found yet. The appearance of extra dimensions in the framework of brane world systems seems to provide some new ideas to a

Wojciech Krolikowski

A particular form of mixing matrix for three active and one sterile neutrinos is proposed. Its $3\times 3 $ part describing three active neutrinos arises from the popular bimaximal mixing matrix that works satisfactorily in solar and atmospheric experiments if the LSND effect is ignored. Then, the sterile neutrino, effective in the fourth row and fourth colu

K. C. Chou, Y. L. Wu

CP violation, fermion masses and mixing angles including that of neutrinos are studied in an SUSY SO(10)$\times Δ(48)\times$ U(1) model. The nonabelian SU(3) discrete family symmetry $Δ(48)$ associated with a simple scheme of U(1) charge assignment on various fields concerned in superpotential leads to unique Yukawa coupling matrices with zero textures. Thir

D. Yu. Peressounko, Yu. E. Pokrovsky

In the frame of 2+1 Bjorken hydrodynamics we describe simultaneously hadron yields and midrapidity pt distributions of direct photons, unflavored, and strange hadrons measured in Pb+Pb collisions at SpS. We find, that a reasonably quantitative description of these data is possible only if we introduce some radial velocity at the beginning of the one-fluid hy

John D. Barrow, Janna Levin

Twins travelling at constant relative velocity will each see the other&#39;s time dilate leading to the apparent paradox that each twin believes the other ages more slowly. In a finite space, the twins can both be on inertial, periodic orbits so that they have the opportunity to compare their ages when their paths cross. As we show, they will agree on their

M. Pierri

Canonical quantization of the polarized Gowdy midi-superspace with a 3-torus spatial topology is carried out. As in an earlier work on the Einstein-Rosen cylindrical waves, symmetry reduction is used to cast the original problem in 4-dimensional space-times to a 3-dimensional setting. To our knowledge, this is the first complete, systematic treatment of the

A. C. V. V. de Siqueira

We use a metric of the type Friedmann-Robertson-Walker to obtain new exact solutions of Einstein equations for a scalar and massive field. The solutions have a permanent or transitory inflationary behavior.

Shmuel Kaniel, Yakov Itin

The equations of motion of massive particles in GR are completely determined by the field equation. We utilize the particular form of Einstein&#39;s field equation and propose for the $N$-body problem of the equations that are Lorentz invariant a novel algorithm for the derivation of the equations of motion from the field equations. It is: 1. Compute a stati

Spiros Cotsakis, John Miritzis

We show that the scalar-tensor $σ$-model action is conformally equivalent to general relativity with a minimally coupled wavemap with a particular target metric. Inflation on the source manifold is then shown to occur in a natural way due both to the arbitrary curvature couplings and the wavemap self-interactions.

Louisa Bokacheva, Andrew D. Kent, Marc A. Walters

The crossover between thermally assisted and pure quantum tunneling has been studied in single crystals of high spin (S=10) uniaxial molecular magnet Mn12 using micro-Hall-effect magnetometry. Magnetic hysteresis and relaxation experiments have been used to investigate the energy levels that determine the magnetization reversal as a function of magnetic fiel

Mohsen Sabouri-Ghomi, Nikolas Provatas, Martin Grant

We simulate solidification in a narrow channel through the use of a phase-field model with an adaptive grid. In different regimes, we find that the solid can grow in fingerlike steady-state shapes, or become unstable, exhibiting unsteady growth. At low melt undercoolings, we find good agreement between our results, theoretical predictions, and experiment. Fo

J. Tempere, J. T. Devreese, E. R. I. Abraham

The quantized vortex state is investigated in a Bose-Einstein condensate, confined in a multiply connected geometry formed by a Laguerre-Gaussian optical trap. Solving the Gross-Pitaevskii equation variationally, we show that the criterium for vortex stability is that the interatomic interaction strength must exceed a critical interaction strength. The time

Avishay Efrat, Moshe Schwartz

Random Ising systems on a general hierarchical lattice with both, random fields and random bonds, are considered. Rigorous inequalities between eigenvalues of the Jacobian renormalization matrix at the pure fixed point are obtained. These inequalities lead to upper bounds on the crossover exponents $\{ϕ_i\}$.

E. A. Jagla

A core-softened model of a glass forming fluid is numerically studied in the limit of very low temperatures. The model shows two qualitatively different behaviors depending on the strength of the attraction between particles. For no or low attraction, the changes of density as a function of pressure are smooth, although hysteretic due to mechanical metastabi

Jae-Weon Lee, In-Ho Lee, Sang Boo Nam

The notion of a finite pairing interaction energy range via Nam, results in the incomplete condensation in which not all states participate in pairings. Thestates not participating in pairings are shown to yield the lowenergy states responsible for the linear T dependence ofsuperelectron density at low T in a s-wave superconductor. Wepresent extensive quanti

S. R. Federman, M. Fritts, S. Cheng, K. M. Menningen

Band oscillator strengths for electronic transitions in CO were obtained at the Synchrotron Radiation Center of the University of Wisconsin-Madison. Our focus was on transitions that are observed in interstellar spectra with the Far Ultraviolet Spectroscopic Explorer; these transitions are also important in studies of selective isotope photodissociation wher

Koji Mukai, Manabu Ishida

We present the results of ASCA and RXTE observations of the early X-ray emission from the classical nova V382 Velorum. Its ASCA spectrum was hard (kT~10 keV) with a strong (10**23 cm**-2) intrinsic absorption. In the subsequent RXTE data, the spectra became softer both due to a declining temperature and a diminishing column. We argue that this places the X-r

S. Castro, R. W. Pogge, R. M. Rich, D. L. DePoy

We present two Keck HIRES spectra (R=40,000) of a bulge K3 giant taken on successive nights during the second caustic crossing of the binary microlensing event EROS BLG-2000-5. This caustic crossing served to effectively resolve the surface of the source star: the spectrum from the second night is dominated by the limb, while the spectrum from the first nigh

Tracy Beck, L. Prato, M. Simon

We present angularly resolved spectra of T Tau North and South in the 3 micron water ice feature and K-band. Most of the water ice absorption lies along the line of sight toward T Tau South, confirming that it is viewed through stronger extinction. A decrease in ice-band absorption toward T Tau S between December 1998 and January 2000, significant at the 2 s

J. C. N. de Araujo, O. D. Miranda, O. D. Aguiar

Recently Fuller & Shi proposed that the gravitational collapse of supermassive objects ($M \gtrsim 10^4M_\odot$) could be a cosmological source of $γ$-ray bursts (GRBs). The major advantage of their model is that supermassive object collapses are far more energetic than solar mass-scale compact mergers. Also, in their proposal the seeds of supermassive black

H. C. Harris, B. M. S. Hansen, J. Liebert, D. E. Vanden Berk

Early data taken during commissioning of the SDSS have resulted in the discovery of a very cool white dwarf. It appears to have stronger collision induced absorption from molecular hydrogen than any other known white dwarf, suggesting it has a cooler temperature than any other. While its distance is presently unknown, it has a surprisingly small proper motio

G. Chartas, M. Bautz, G. Garmire, C. Jones

An observation of the gravitationally lensed system 2016+112 with the Chandra X-ray Observatory has resolved a mystery regarding the proposed presence of a dark matter object in the lens plane of this system. The Chandra ACIS observation has clearly detected the lensed images of 2016+112 with positions in good agreement with those reported in the optical and

Jurgen Knodlseder, Gilbert Vedrenne

After the recent beautiful results on gamma-ray lines obtained with CGRO, the INTEGRAL mission with the imaging-spectrometer SPI will set the next milestone, combining improved sensitivity and angular resolution with a considerable increase in spectral resolution. SPI is expected to provide significant new information on galactic nucleosynthesis processes an

Peter A. Becker, Prasad Subramanian, Demosthenes Kazanas

The Newtonian ADAF model has been generalized recently to obtain the ADIOS model that includes outflows of energy and angular momentum. The utilization of a Newtonian gravitational potential limits the ability of the ADIOS model to describe the inner region of the disk, where any relativistic outflows are likely to originate. In this paper we modify the ADIO

Varun Sahni

I describe a new class of quintessence+CDM models in which late time scalar field oscillations can give rise to both quintessence and cold dark matter. Additionally, a versatile ansatz for the luminosity distance is used to reconstruct the quintessence equation of state in a model independent manner from observations of high redshift supernovae.

Hong Liu, Jeremy Michelson

We discuss the supergravity couplings of noncommutative D-branes by considering the disk amplitudes with one closed string insertion. The result confirms a recent proposal for the general form of the noncommutative Yang-Mills operators coupling to the massless closed string modes. The construction involves smearing Yang-Mills field variables along an open Wi

L. R. Abramo, F. Finelli

We investigate the evolution of cosmological perturbations in scenarios with a quintessence scalar field, both analytically and numerically. In the tracking regime for quintessence, we find the long wavelength solutions for quintessential perturbations. We discuss the possibility of isocurvature modes generated by the quintessence sector and their impact on

R. X. Xu, X. B. Xu, X. J. Wu

According to the observational limits on the radius and mass, the fastest rotating pulsar (PSR 1937+21) is probably a strange star, or at least some neutron star equations of state should be ruled out, if we suggest that a dipole magnetic field is relevant to its radio emission. We presume that the millisecond pulsar is a strange star with {\em much} low mas

Klaus Behrndt, Mirjam Cvetic

We provide the explicit gauging of all the SU(2,1) isometries of one N=2 supergravity hypermultiplet, which spans SU(2,1)/U(2) coset space parameterized in terms of two complex projective coordinate fields z_1 and z_2. We derive the full, explicit Killing prepotential that specifies the most general superpotential. As an application we consider the supersymm

R. X. Xu, J. W. Xu, G. J. Qiao

It is of great important to study pulsar beam shapes if we are concerned with emission theories and pulsar birth rate. Both observations and/or the inverse Compton scattering model show that different emission components are emitted from different heights. The relative longitude phase shifts due to different heights of emission components and to the toroidal

R. X. Xu, F. H. Busse

It is shown that protostrange stars (PSSs) can be convective and that there are two possible scenarios describing their turbulence. Besides the local turbulence on the scale which is less than the mean free path of neutrinos, large-scale (~1 km) convection also may occur with properties that are similar to those of convection in protoneutron stars (PNSs). We

Ofer Aharony

We discuss the field theory interpretation (via holographic duality) of some recently-discovered string theory solutions with varying flux, focusing on four dimensional theories with N=2 supersymmetry and with N=1 supersymmetry which arise as the near-horizon limits of &#34;fractional D3-branes&#34;. We argue that in the N=2 case the best interpretation of t

Brandon Carter, Jean-Philippe Uzan

This article synthesises and extends recent work on the cosmological consequences of dropping the usual Z_2 reflection symmetry postulate in brane world scenarios. It is observed that for a cosmological model of homogeneous isotropic type, the relevant generalised Birkhoff theorem establishing staticity of the external vacuum in the maximally symmetric ``bul

Da Qing Liu, Ying Chen, Ji Min Wu

An observation of autocorrelation of Wilson loops on lattice is presented, especially for the small seperation in Markov chain. We give a possible explanation for such behavior. We also present the dependence of autocorrelation behavior on the chosen operators in this paper.

Z. Haba, H. Kleinert

From a forward--backward path integral, we derive a master equation for the emission and absorption of gravitons by a massive quantum object in a heat bath of gravitons. Such an equation could describe collapse phenomena of dense stars. We also present a useful approximate Langevin equation for such a system.

Gilles Brassard

Can quantum communication be more efficient than its classical counterpart? Holevo&#39;s theorem rules out the possibility of communicating more than n bits of classical information by the transmission of n quantum bits --- unless the two parties are entangled, in which case twice as many classical bits can be communicated but no more. In apparent contradict

B. Georgeot, D. L. Shepelyansky

We show on the example of the Arnold cat map that classical chaotic systems can be simulated with exponential efficiency on a quantum computer. Although classical computer errors grow exponentially with time, the quantum algorithm with moderate imperfections is able to simulate accurately the unstable chaotic classical dynamics for long times. The algorithm

Subhash Kak

This paper shows that characteristic features of Puranic cosmology, such as alternating cosmic continents and oceans of successively doubling areas, can be traced to Vedic texts. The Rigveda speaks of seven regions of the universe, and Yajnavalkya, in Brihadaranyaka Upanishad, presents a cosmology that has all the essential features of the Puranic system. Th

Armando Barrañón

Alonso de la Veracruz conducted a physical study of image, regarding the activities of Soul in which image is produced, as organic operations. This research was particularly important since, at that time, image was systematically used to propagate the European culture in New Spain. Besides, Alonso uses the visual radius to criticize the magical attitude popu

Ingo Braun, Guido Ihlein, Franco Laeri, Jens U. Noeckel

Molecular sieves, such as nanoporous AlPO_4-5, can host a wide variety of laser active dyes. We embedded pyridine 2 molecules as a representative of a commercially available dye which fits into the channel pores of the host matrix. Many efficient dye molecules, such as rhodamines, do not fit into the pores. But the amount of encapsulated dyes can be increase

M. K. Banerjee, J. A. Tjon

Recently we showed that while the tensor force plays an important role in nuclear matter saturation in non-relativistic studies, it does not do so in relativistic studies. The reason behind this is the role of $M^*$, the sum of nucleon mass and its attractive self-energy in nuclear matter. Yet nonrelativistic calculations at a certain level of approximation

Andrey Tsiganov

We discuss some special classes of canonical transformations of the extended phase space, which relate integrable systems with a common Lagrangian submanifold. Various parametric forms of trajectories are associated with different integrals of motion, Lax equations, separated variables and action-angles variables. In this review we will discuss namely these

Larisa A. Khodarinova, I. A. Prikhodsky

Algebraic integrability of the elliptic Calogero--Moser quantum problem related to the deformed root systems $\pbf{A_{2}(2)}$ is proved. Explicit formulae for integrals are found.

Andrey N. Leznov

The $2n$ dimensional manifold with two mutually commutative operators of differentiation is introduced. Nontrivial multidimensional integrable systems connected with arbitrary graded (semisimple) algebras are constructed. The general solution of them is presented in explicit form.

Simon N. M. Ruijsenaars

We introduce and study a class of analytic difference operators admitting reflectionless eigenfunctions. Our construction of the class is patterned after the Inverse Scattering Transform for the reflectionless self-adjoint Schrödinger and Jacobi operators corresponding to KdV and Toda lattice solitons.

Harj S. Dhillon, Fjodor V. Kusmartsev, Karl E. Kürten

We discuss stationary solutions of the discrete nonlinear Schrödinger equation (DNSE) with a potential of the $ϕ^{4}$ type which is generically applicable to several quantum spin, electron and classical lattice systems. We show that there may arise chaotic spatial structures in the form of incommensurate or irregular quantum states. As a first (typical) exam

Oleg M. Kiselev

A special asymptotic solution of the Painlevé-2 equation with small parameter is studied. This solution has a critical point $t_*$ corresponding to a bifurcation phenomenon. When $t<t_*$ the constructed solution varies slowly and when $t>t_*$ the solution oscillates very fast. We investigate the transitional layer in detail and obtain a smooth asymptotic sol

Alexander Sergeev

A depending on a complex parameter $k$ superanalog ${\mathcal S}{\mathcal L}$ of Calogero operator is constructed; it is related with the root system of the Lie superalgebra ${\mathfrak{gl}}(n|m)$. For $m=0$ we obtain the usual Calogero operator; for $m=1$ we obtain, up to a change of indeterminates and parameter $k$ the operator constructed by Veselov, Chal

J. Lewis, D. Zagier

Recall that a Maass wave form on the full modular group Gamma=PSL(2,Z) is a smooth gamma-invariant function u from the upper half-plane H = {x+iy | y>0} to C which is small as y \to \infty and satisfies Delta u = lambda u for some lambda \in C, where Delta = y^2(d^2/dx^2 + d^2/dy^2) is the hyperbolic Laplacian. These functions give a basis for L_2 on the mod

Shouwu Zhang

The purpose of this paper is to generalize some results of Gross-Zagier [20] and Kolvyvagin [28] to totally real fields.

F. Reese Harvey, H. Blaine Lawson,

In this paper we present a new approach to Morse theory based on the de Rham-Federer theory of currents. The full classical theory is derived in a transparent way. The methods carry over uniformly to the equivariant and the holomorphic settings. Moreover, the methods are substantially stronger than the classical ones and have interesting applications to geom

I. A. Shereshevski\uı

I propose an orthogonalization procedure preserving the grading of the initial graded set of linearly independent vectors. In particular, this procedure is applicable for orthonormalization of any countable set of polynomials in several (finitely many) indeterminates.

Pavel Grozman

Let $M$ be an $n$-dimensional manifold, $V$ the space of a representation $ρ: GL(n)\longrightarrow GL(V)$. Locally, let $T(V)$ be the space of sections of the tensor bundle with fiber $V$ over a sufficiently small open set $U\subset M$, in other words, $T(V)$ is the space of tensor fields of type $V$ on $M$ on which the group $\Diff (M)$ of diffeomorphisms o

Johan Byström

In this paper we study homogenization of quasi-linear partial differential equations of the form $-\mbox{div}\left( a\left( x,x/\varepsilon _h,Du_h\right) \right) =f_h$ on $Ω$ with Dirichlet boundary conditions. Here the sequence $\left( \varepsilon _h\right) $ tends to $0$ as $h\rightarrow \infty $ and the map $a\left( x,y,ξ\right) $ is periodic in $y,$ mon

Alexander Fel&#39;shtyn

We show that the number of twisted conjugacy classes is infinite for any automorphism of non-elementary, Gromov hyperbolic group . An analog of Selberg theory for twisted conjugacy classes is proposed.

A. Boettcher

We give alternative proofs to (block case versions of) some formulas for Toeplitz and Fredholm determinants established recently by the authors of the title. Our proof of the Borodin-Okounkov formula is very short and direct. The proof of the Baik-Deift-Rains formulas is based on standard manipulations with Wiener-Hopf factorizations.

L. Cornalba

We show, with a 2-dimensional example, that the low energy effective action which describes the physics of a single D-brane is compatible with T-duality whenever the corresponding U(N) non-abelian action is form-invariant under the non-commutative Seiberg-Witten transformations.

Partha Mukhopadhyay, Ashoke Sen

We test the validity of the Siegel gauge condition for the lump solution of cubic open bosonic string field theory by checking the equations of motion of the string field components outside the Siegel gauge. At level (3,6) approximation, the linear and quadratic terms of the equations of motion of these fields are found to cancel within about 20%.

A. A. Belavin, S. Yu. Gubanov, B. L. Feigin

This is the abstract of the revised paper. The integrable XXZ model with a special open boundary condition is considered. We study Sklyanin transfer matrices after quantum group reduction in roots of unity. In this case Sklyanin transfer matrices satisfy a closed system of truncated functional equations. The algebraic reason for the truncation is found.The i

L. Cornalba

We discuss the general structure of the non-abelian Born-Infeld action, together with all of the alpha-prime derivative corrections, in flat D-dimensional space-time. More specifically, we show how the connection between open strings propagating in background magnetic fields and gauge theories on non-commutative spaces can be used to constrain the form of th

Paul M. Fishbane, Peter Kaus

We consider two-family neutrino oscillations in a medium of continuously-varying density as a limit of the process in a series of constant-density layers. We construct analytic expressions for the conversion amplitude at high energies within a medium with a density profile that is piecewise linear. We compare some cases to understand the type of effects that

John Womersley

I shall review the present status of Tevatron QCD studies, focusing on the production of jets, vector bosons, photons and heavy quarks. In general there is good agreement between the results of current calculational tools and the experimental data. The major areas of discrepancy arise when the input parton distributions become uncertain (for example, jets at

Javier Chavarriga, I. A. García

The Einstein field equations for several cosmological models reduce to polynomial systems of ordinary differential equations. In this paper we shall concentrate our attention to the spatially homogeneous diagonal G_2 cosmologies. By using Darboux&#39;s theory in order to study ordinary differential equations in the complex projective plane CP^2 we solve the

Don N. Page

If one surrounds a black hole with a perfectly reflecting shell and adiabatically squeezes the shell inward, one can increase the black hole area A to exceed four times the total entropy S, which stays fixed during the process. A can be made to exceed 4S by a factor of order unity before the one enters the Planck regime where the semiclassical approximation

Yu. V. Kalyuzhnyi, P. T. Cummings

The analytical solution of the recently proposed ideal chain polymer mean-spherical approximation (Yu.Kalyuzhnyi, Mol.Phys., 94, 735(1998)) is presented for the multicomponent mixture of charged hard-sphere linear chain flexible molecules. The solution apply to any mixture of chain molecules with arbitrary distribution of the charge and size of the beads alo

Tiziana Di Matteo, Tomaso Aste

An empirical analysis on Eurodollar interest rates daily data in the time period 1990-1996, is performed and compared with Libor data in the time period 1984-1998. The complementary cumulative distributions for the daily fluctuations at different maturity dates and the Power Spectral Density are computed. We find that the probability distribution shows `fat&

Luca Salasnich

We discuss thermal and dynamical properties of Bose condensates confined by an external potential. First we analyze the Bose-Einstein transition temperature for an ideal Bose gas in a generic power-law potential and d-dimensional space. Then we investigate the effect of the shape of the trapping potential on the properties of a weakly-interacting Bose conden

Shoji Yamamoto

We study the electronic structure of halogen-bridged binuclear metal (MMX) complexes with a two-band Peierls-Hubbard model. Based on a symmetry argument, various density-wave states are derived and characterized. The ground-state phase diagram is drawn within the Hartree-Fock approximation, while the thermal behavior is investigated using a quantum Monte Car

A. D. Chepelianskii, D. L. Shepelyansky

We study numerically and analytically the dynamics of particles on the Galton board, a regular lattice of disc scatters, in the presence of a constant external force and friction. It is shown that under certain conditions friction leads to the appearance of a strange chaotic attractor in an initially conservative Hamiltonian system. In this regime the partic

C. R. Benn

The WHT is unusually well-placed for exploitation of adaptive-optics (AO) technology. The site seeing is excellent (median 0.7 arcsec), dome seeing is negligible, and preliminary studies indicate that most of the atmospheric seeing originates in a well-defined layer at low altitude, which bodes well for future laser-guide-star AO. The Durham group have built

G. Cecil, J. Bland-Hawthorn, S. Veilleux, A. V. Filippenko

HST WFPC2 images are presented that span the inner 19 kpc diameter of the edge-on spiral galaxy NGC 3079; they are combined with ground-based Halpha+[N II] Fabry-Perot spectra and VLA images of radio polarization vectors and rotation measures. Ionized gas filaments within 9 kpc diameter project ~3 kpc above the disk, with the brightest forming the 1 kpc diam

Kazunari Shibata, Syuniti Tanuma

As a key to undertanding the basic mechanism for fast reconnection in solar flares, plasmoid-induced-reconnection and fractal reconnection are proposed and examined. We first briefly summarize recent solar observations that give us hints on the role of plasmoid (flux rope) ejections in flare energy release. We then discuss the plasmoid-induced-reconnection m

Arnon Dar

Recent observations suggest that gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in core collapse supernova explosions (SNe). The result of the event, probably, is not just a compact object plus a spherical ejecta: within days, a fraction of the parent star falls back to produce a thick accretion disk around the