December 2005 arXiv papers — page 15

Rouzbeh Allahverdi, Anupam Mazumdar

Motivated by our earlier paper \cite{am}, we discuss how the infamous gravitino problem has a natural built in solution within supersymmetry. Supersymmetry allows a large number of flat directions made up of {\it gauge invariant} combinations of squarks and sleptons. Out of many at least {\it one} generically obtains a large vacuum expectation value during i

J. M. Isidro

We prove that a gerbe with a connection can be defined on classical phase space, taking the U(1)-valued phase of certain Feynman path integrals as Cech 2-cocycles. A quantisation condition on the corresponding 3-form field strength is proved to be equivalent to Heisenberg's uncertainty principle.

Takao Sakaguchi

Direct photon production in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV has been measured in the $p_T$ range of 1$<$$p_T$$<$5 GeV/$c$. The yield as acfunction of centrality is in agreement with published data of the RHIC 2002 run, and with results from a new method that explores very low mass dileptons. The result is compared to several theoretical calculati

G. S. Adams, CLEO Collaboration

Using data acquired with the CLEO detector at the CESR e+e- collider at sqrt{s} = 3.773 GeV, we measure the cross section for the radiative return process e+e- --> gamma J/psi, J/psi --> mu+mu-, resulting in B(J/psi --> mu+mu-) x Gamma_ee(J/psi) = 0.3384 +- 0.0058 +- 0.0071 keV, Gamma_ee(J/psi) = 5.68 +- 0.11 +- 0.13 keV, and Gamma_tot(J/psi) = 95.5 +- 2.4 +

Stephen D. Hicks, C. L. Henley

We model the spontaneous assembly of a capsid (a virus&#39;s closed outer shell) from many copies of identical units, using entirely irreversible steps and only information local to the growing edge. Our model is formulated in terms of (i) an elastic Hamiltonian with stretching and bending stiffness and a spontaneous curvature, and (ii) a set of rate constan

Biswajit Banerjee

Phenomenological plastic flow stress models are used extensively in the simulation of large deformations of metals at high strain-rates and high temperatures. Several such models exist and it is difficult to determine the applicability of any single model to the particular problem at hand. Ideally, the models are based on the underlying (subgrid) physics and

Tae W. Kang, Alon Retter, Alex Liu, Mercedes Richards

We present the results of 37 nights of CCD unfiltered photometry of nova V2574 Oph (2004) from 2004 and 2005. We find two periods of 0.14164 d (~3.40 h) and 0.14773 d (~3.55 h) in the 2005 data. The 2004 data show variability on a similar timescale, but no coherent periodicity was found. We suggest that the longer periodicity is the orbital period of the und

A. L. Maroto

We explore the possibility that the rest frames of CMB, matter and dark energy differ one from another, i.e. they do not converge on very large scales. In such a case, the usual interpretation of the CMB dipole as being due to the relative motion of the observer with respect to the CMB rest frame is not appropriate. Instead, we find that the measured dipole

S. E. Derkachov, A. N. Manashov

It is shown that the transfer matrices of homogeneous sl(2) invariant spin chains with generic spin, both closed and open, are factorized into the product of two operators. The latter satisfy the Baxter equation that follows from the structure of the reducible representations of the sl(2) algebra.

Gastão A. Braga, Frederico Furtado, Jussara M. Moreira, Leonardo T. Rolla

We study the long-time asymptotics of a certain class of nonlinear diffusion equations with time-dependent diffusion coefficients which arise, for instance, in the study of transport by randomly fluctuating velocity fields. Our primary goal is to understand the interplay between anomalous diffusion and nonlinearity in determining the long-time behavior of so

M. Wouters, I. Carusotto

We analytically investigate the spatial coherence properties of the signal emission from one-dimensional optical parametric oscillators. Because of the reduced dimensionality, quantum fluctuations are able to destroy the long-range phase coherence even far above threshold. The spatial decay of coherence is exponential and, for realistic parameters of semicon

L. M. Winter, R. F. Mushotzky, C. S. Reynolds

We present the results of an archival XMM-Newton study of the bright X-ray point sources (L_X > 10^38 erg/s) in 32 nearby galaxies. From our list of approximately 100 point sources, we attempt to determine if there is a low-state counterpart to the Ultraluminous X-ray (ULX) population, searching for a soft-hard state dichotomy similar to that known for Galac

Andrzej J. Buras

I describe the early days of the photon structure functions. In particular I discuss the parton model result of Walsh and Zerwas (1973), leading order QCD calculation of Witten (1976) and next-to-leading QCD calculation of Bardeen and myself (1978). A very brief summary of the progress made from 1978 until 2005 is also given.

Pablo G. Camara

We review some of the features of Type IIA compactifications in the presence of fluxes. In particular, the case of $T^6/(Ω(-1)^{F_L} σ)$ orientifolds with RR, NS and metric fluxes is considered. This has revealed to possess remarkable properties such as vacua with all the closed string moduli stabilized, null or negative contributions to the RR tadpoles or s

Guido Altarelli, Richard D. Ball, Stefano Forte

We present a small x resummation for the GLAP anomalous dimension and its corresponding dual BFKL kernel, which includes all the available perturbative information and nonperturbative constraints. Specifically, it includes all the information coming from next-to-leading order GLAP anomalous dimensions and BFKL kernels, from the constraints of momentum conser

Sylvain Ribault

I show how the AdS2 D-branes in the Euclidean AdS3 string theory are related to the continuous D-branes in Liouville theory. I then propose new discrete D-branes in the Euclidean AdS3 which correspond to the discrete D-branes in Liouville theory. These new D-branes satisfy the appropriate shift equations. They give rise to two families of discrete D-branes i

Redamy Perez Ramos, Bruno Machet

After demonstrating their general expressions valid at all x, double differential 1-particle inclusive distributions inside a quark and a gluon jet produced in a hard process, together with the inclusive k-transverse distributions, are calculated at small x in the Modified Leading Logarithmic Approximation (MLLA), as functions of the transverse momentum of t

Phongpichit Channuie, Teparksorn Pengpan, Witsanu Puttawong

After introducing the generators and irreducible representations of the ${\rm su}(5)$ and ${\rm so}(6)$ Lie algebras in terms of the Schwinger&#39;s scillators, the general kernel solutions of the Kostant operators on eight-dimensional quotient spaces ${\rm su}(5)/{\rm su}(4)\times {\rm u}(1)$ and ${\rm so}(6)/{\rm so}(4)\times {\rm so}(2)$ are derived in te

Steven J. Miller, Eric T. Bradlow, Kevin Dayaratna

Articles in Marketing and choice literatures have demonstrated the need for incorporating person-level heterogeneity into behavioral models (e.g., logit models for multiple binary outcomes as studied here). However, the logit likelihood extended with a population distribution of heterogeneity doesn&#39;t yield closed-form inferences, and therefore numerical

Laurence Littenberg

Recent results in and future prospects for the study of rare kaon decays are reviewed.

S. L. Cherkas, V. L. Kalashnikov

The quasi-Heisenberg picture of minisuperspace model is considered. The The quasi-Heisenberg picture of minisuperspace model is considered. The suggested scheme consists in quantizing of the equation of motion and interprets all observables including the Universe scale factor as the time-dependent (quasi-Heisenbeg) operators acting in the space of solutions

B. M. Zupnik

We study the problem of reality in the geometric formalism of the 4D noncommutative gravity using the known deformation of the diffeomorphism group induced by the twist operator with the constant deformation parameters $\vt^{mn}$. It is shown that real covariant derivatives can be constructed via $\star$-anticommutators of the real connection with the corres

Srubabati Goswami, Werner Rodejohann

We analyze the constraints on neutrino mass spectra with extra sterile neutrinos as implied by the LSND experiment. The various mass related observables in neutrinoless double beta decay, tritium beta decay and cosmology are discussed. Both neutrino oscillation results as well as recent cosmological neutrino mass bounds are taken into account. We find that s

Richard D. Gill

We derive an asymptotic lower bound on the Bayes risk when N identical quantum systems whose state depends on a vector of unknown parameters are jointly measured in an arbitrary way and the parameters of interest estimated on the basis of the resulting data. The bound is an integrated version of a quantum Cram\'er-Rao bound due to Holevo (1982), and it there

S. Mieske, M. Hilker, L. Infante, A. Jordan

Various formation channels for the puzzling ultra-compact dwarf galaxies (UCDs) have been proposed in the last few years. To better judge on some of the competing scenarios, we present spectroscopic [Fe/H] estimates for a sample of 26 compact objects in the central region of the Fornax cluster, covering the magnitude range of UCDs and bright globular cluster

Simone Speziale

Recently, a proposal has appeared for the extraction of the 2-point function of linearised quantum gravity, within the spinfoam formalism. This relies on the use of a boundary state, which introduces a semi-classical flat geometry on the boundary. In this paper, we investigate this proposal considering a toy model in the (Riemannian) 3d case, where the semi-

Zhixin Qian

Inelastic lifetime of an electron quasiparticle in an electron liquid due to electron-electron interaction evaluated in previous work is calculated in an alternative way. Both the contributions of the &#34;direct&#34; and &#34;exchange&#34; processes are included. The results turn out to be exactly the same as those obtained previously, and hence confirm the

Sean Clark

The d-level or qudit one-way quantum computer (d1WQC) is described using the valence bond solid formalism and the generalised Pauli group. This formalism provides a transparent means of deriving measurement patterns for the implementation of quantum gates in the computational model. We introduce a new universal set of qudit gates and use it to give a constru

Hiroyuki Yoshiguchi, Shinji Mukohyama, Yuuiti Sendouda, Shunichiro Kinoshita

We show the dynamical stability of a six-dimensional braneworld solution with warped flux compactification recently found by the authors. We consider linear perturbations around this background spacetime, assuming the axisymmetry in the extra dimensions. The perturbations are expanded by scalar-, vector- and tensor-type harmonics of the four-dimensional Mink

N. Kawamoto, K. Miura, A. Ohnishi, T. Ohnuma

We study the phase diagram of quark matter at finite temperature (T) and finite chemical potential (mu) in the strong coupling limit of lattice QCD for color SU(3). We derive an analytical expression of the effective free energy as a function of T and mu, including baryon effects. The finite temperature effects are evaluated by integrating over the temporal

Masato Arai, Nobuchika Okada

We study vacuum structure of N=2 supersymmetric (SUSY) QCD, based on the gauge group SU(2) with N_f=2 flavors of massive hypermultiplet quarks, in the presence of non-zero baryon chemical potential (μ). The theory has a classical vacuum preserving baryon number symmetry, when a mass term, which breaks N=2 SUSY but preserves N=1 SUSY, for the adjoint gauge ch

V. Janis, A. Klic

We analyze the replica-symmetry-breaking construction in the Sherrington-Kirkpatrick model of a spin glass. We present a general scheme for deriving an exact asymptotic behavior near the critical temperature of the solution with an arbitrary number of discrete hierarchies of the broken replica symmetry. We show that all solutions with finite-many hierarchies

Samad Behroozi, Shahriar Rouhani, Mohammad Vahid Takook, Mohammad Reza Tanhayi

Conformally invariant wave equations in de Sitter space, for scalar and vector fields, are introduced in the present paper. Solutions of their wave equations and the related two-point functions, in the ambient space notation, have been calculated. The ``Hilbert&#39;&#39; space structure and the field operator, in terms of coordinate independent de Sitter pla

Vasilis Niarchos

In this paper we consider tree-level scattering in the minimal N=4 topological string and show that a large class of N-point functions can be recast in terms of corresponding amplitudes in the (1,k) minimal bosonic string. This suggests a non-trivial relation between the minimal N=4 topological strings, the (1,k) minimal bosonic strings and their correspondi

Supratik Pal, Sayan Kar

The `braneworld&#39; (described by the usual worldvolume action) is a D dimensional timelike surface embedded in a N dimensional ($N>D$) warped, nonfactorisable spacetime. We first address the conditions on the warp factor required to have an extremal flat brane in a five dimensional background. Subsequently, we deal with normal deformations of such extremal

David Pask, Adam Rennie, Aidan Sims

This paper is comprised of two related parts. First we discuss which k-graph algebras have faithful gauge invariant traces, where the gauge action of $\T^k$ is the canonical one. We give a sufficient condition for the existence of such a trace, identify the C*-algebras of k-graphs satisfying this condition up to Morita equivalence, and compute their K-theory

D. Ebert, R. N. Faustov, V. O. Galkin

The masses of heavy tetraquarks with hidden charm and bottom are calculated in the framework of the relativistic quark model. The tetraquark is considered as the bound state of a heavy-light diquark and antidiquark. The light quark in a heavy-light diquark is treated completely relativistically. The internal structure of the diquark is taken into account by

P. Kroll

Results from a recent analysis of the zero-skewness generalized parton distributions (GPDs) for valence quarks are reviewed. The analysis bases on a physically motivated parameterization of the GPDs with a few free parameters adjusted to the nucleon form factor data. The Fourier transforms of the GPDs representing quark densities in the impact parameter plan

Z. C. Tu, Zicong Zhou

The crucial condition in the derivation of the Jarzynski equality (JE) from the fluctuation theorem is that the time integral of the phase space contraction factor can be exactly expressed as the entropy production resulting from the heat absorbed by the system from the thermal bath. For the system violating this condition, a more general form of JE may exis

D. Sluse, J. -F. Claeskens, B. Altieri, R. A. Cabanac

(abridged) Aims: RXS J113155.4-123155 (z=0.66) is a quadruply imaged lensed quasar with a resolved Einstein Ring. The goal of this paper is to provide a full characterization of this system, and more particularly accurate astrometry and photometry. Method: Visible and near-infrared imaging observations of RXS J113155.4-123155 were carried out at various epoc

M. Daghofer, M. Konegger, H. G. Evertz, W. von der Linden

Multimodal structures in the sampling density (e.g. two competing phases) can be a serious problem for traditional Markov Chain Monte Carlo (MCMC), because correct sampling of the different structures can only be guaranteed for infinite sampling time. Samples may not decouple from the initial configuration for a long time and autocorrelation times may be har

P. A. Horvathy

The dynamical (super)symmetries for various monopole systems are reviewed. For a Dirac monopole, no smooth Runge-Lenz vector can exist; there is, however, a spectrum-generating conformal $o(2,1)$ dynamical symmetry that extends into $osp(1/1)$ or $osp(1/2)$ for spin 1/2 particles. Self-dual 't Hooft-Polyakov-type monopoles admit an $su(2/2)$ dynamical supers

Ll. Masanes

A multipartite quantum state violates a Bell inequality asymptotically if, after jointly processing by general local operations an arbitrarily large number of copies of it, the result violates the inequality. In the bipartite case we show that asymptotic violation of the CHSH-inequality is equivalent to distillability. Hence, bound entangled states do not vi

James G. Gilson

Astronomical measurements of the Omegas for mass density, cosmological constant lambda and curvature k are shown to be sufficient to produce a unique and detailed cosmological model describing dark energy influences based on the Friedman equations. The equation of state Pressure turns out to be identically zero at all epochs as a result of the theory. The pa

Charanjit Singh Aulakh, Sumit Kumar Garg

By a systematic survey of the parameter space we confirm our surmise\cite{gmblm} that the Minimal Supersymmetric GUT(MSGUT) based on the ${\bf{210\oplus 126\oplus {\bar {126}}\oplus 10}}$ Higgs system is incompatible with the generic Type I and Type II seesaw mechanisms. The incompatibility of the Type II seesaw mechanism with this MSGUT is due to its generi

Germain Rousseaux, Shahar Seifer, Victor Steinberg, Alexander Wiebel

This work is an attempt to test the concept of hydrodynamic charge (analogous to the electric charge in Electromagnetism) in the simple case of a coherent structure such as the Burgers vortex. We provide experimental measurements of both the so-called Lamb vector and its divergence (the charge) by two-dimensional Particle Image Velocimetry. In addition, we p

L. Bergamin, D. Grumiller, W. Kummer, D. V. Vassilevich

Requiring the presence of a horizon imposes constraints on the physical phase space. After a careful analysis of dilaton gravity in 2D with boundaries (including the Schwarzschild and Witten black holes as prominent examples), it is shown that the classical physical phase space is smaller as compared to the generic case if horizon constraints are imposed. Co

Stoytcho S. Yazadjiev

We consider 5-dimensional Einstein-dilaton gravity with antisymmetric forms. Assuming staticity and a restriction on the dilaton coupling parameters, we derive 4-dimensional sigma-model with a target space $SL(2,R)/SO(1,1)\times SL(2,R)/SO(1,1)$. On this basis, using the symmetries of the target space, we develop a solution generating technique and employ it

Jan Wiersig, Martina Hentschel

We introduce a new scheme to design optical microcavities supporting high-Q modes with unidirectional light emission. This is achieved by coupling a low-Q mode with unidirectional emission to a high-Q mode. The coupling is due to enhanced dynamical tunneling near an avoided resonance crossing. Numerical results for a microdisk with a suitably positioned air

Albrecht Klemm, Marcos Marino

We study topological string amplitudes for the FHSV model using various techniques. This model has a type II realization involving a Calabi-Yau threefold with Enriques fibres, which we call the Enriques Calabi-Yau. By applying heterotic/type IIA duality, we compute the topological amplitudes in the fibre to all genera. It turns out that there are two differe

Aki-Hiro Sato

Power spectrum densities for the number of tick quotes per minute (market activity) on three currency markets (USD/JPY, EUR/USD, and JPY/EUR) for periods from January 1999 to December 2000 are analyzed. We find some peaks on the power spectrum densities at a few minutes. We develop the double-threshold agent model and confirm that stochastic resonance occurs

R. K. Zheng

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Jiansheng Wu, Philip Phillips

We consider the disordered quantum rotor model in the presence of a magnetic field. We analyze the transport properties in the vicinity of the multicritical point between the superconductor, phase glass and paramagnetic phases. We find that the magnetic field leaves metallic transport of bosons in the glassy phase in tact. In the vicinity of the vicinity of

Katrin Wendland

This work gives a manual for constructing superconformal field theories associated to a family of smooth K3 surfaces. A direct method is not known, but a combination of orbifold techniques with a non-classical duality turns out to yield such models. A four parameter family of superconformal field theories associated to certain quartic K3 surfaces in CP^3 is

Daniele Oriti

This is an introduction to the group field theory approach to quantum gravity, with emphasis on motivations and basic formalism, more than on recent results; we elaborate on the various ingredients, both conceptual and formal, of the approach, giving some examples, and we discuss some perspectives of future developments.

Hideo Hasegawa

Finite $N$-unit Langevin models with additive and multiplicative noises have been studied with the use of the augmented moment method (AMM) previously proposed by the author [H. Hasegawa, Phys. Rev E {\bf 67}, 041903 (2003)]. Original $N$-dimensional stochastic equations are transformed to the three-dimensional deterministic equations for means and fluctuati

Hui Jing, Ming-Sheng Zhan

By using a quantized input light, we theoretically revisit the coherent two-color photo-association process in an atomic Bose-Einstein condensate. Under the single-mode approximations, we show two interesting regimes of the light transmission and the molecular generation. The quantum state transfer from light to molecules is exhibited, without or with the de

A. G. Smirnov

We study the localization properties of generalized functions defined on a broad class of spaces of entire analytic test functions. This class, which includes all Gelfand--Shilov spaces $S^β_α(\R^k)$ with $β<1$, provides a convenient language for describing quantum fields with a highly singular infrared behavior. We show that the carrier cone notion, which r

Francesc S. Roig

The von Neumann interaction between a particle and an apparatus has been considered in the measurement of the position of a particle when the interaction lasts for a finite amount of time. When the measurement has finite duration, both the motion of the pointer and the particle influence the result of the measurement. Provided that the particle is in an eige

Edward Farhi, Jeffrey Goldstone, Sam Gutmann, Daniel Nagaj

The quantum adiabatic algorithm is a Hamiltonian based quantum algorithm designed to find the minimum of a classical cost function whose domain has size N. We show that poor choices for the Hamiltonian can guarantee that the algorithm will not find the minimum if the run time grows more slowly than square root of N. These poor choices are nonlocal and wash o

Henrik Brusheim-Johansson

A non-local toy-model is proposed for the purpose of modelling the ``wave function collapse&#39;&#39; of a two-state quantum system. The collapse is driven by a nonlinear evolution equation with an extreme sensitivity to absolute phase. It is hypothesized that the phase, or a part of it, is displaying chaotic behaviour. This chaotic behaviour can then be res

Wojciech Wasilewski, M. G. Raymer

We analyze quantum entanglement of Stokes light and atomic electronic polarization excited during single-pass, linear-regime, stimulated Raman scattering in terms of optical wave-packet modes and atomic-ensemble spatial modes. The output of this process is confirmed to be decomposable into multiple discrete, bosonic mode pairs, each pair undergoing independe

L. P. Gilbert, M. Belloni, M. A. Doncheski, R. W. Robinett

We extend the standard treatment of the asymmetric infinite square well to include solutions that have zero curvature over part of the well. This type of solution, both within the specific context of the asymmetric infinite square well and within the broader context of bound states of arbitrary piecewise-constant potential energy functions, is not often disc

Vincent Delaubert, Nicolas Treps, Gao Bo, Claude Fabre

We propose an optical read-out scheme allowing a demonstration of principle of information extraction below the diffraction limit. This technique, which could lead to improvement in data read-out density onto optical discs, is independent from the wavelength and numerical aperture of the reading apparatus, and involves a multi-pixel array detector. Furthermo

Vincent Delaubert, Nicolas Treps, Charles C. Harb, Ping Koy Lam

We consider the problem of measurement of optical transverse profile parameters and their conjugate variable. Using multi-mode analysis, we introduce the concept of detection noise-modes. For Gaussian beams, displacement and tilt are a pair of transverse profile conjugate variables. We experimentally demonstrate their optimal encoding and detection with a sp

Qi-Ren Zhang

We show that the non-locality together with the statistical character makes the world statistically separable. The super-luminal signal transmission is impossible. The quantum theory is therefore consistent with the relativity and the causality.

L. Tian, S. M. Carr

We study a quantum teleportation scheme between two nanomechanical modes without local interaction. The nanomechanical modes are linearly coupled to and connected by the continuous variable modes of a superconducting circuit consisting of a transmission line and Josephson junctions. We calculate the fidelity of transferring Gaussian states at finite temperat

H. Atmanspacher, P. beim Graben

The emergence of mental states from neural states by partitioning the neural phase space is analyzed in terms of symbolic dynamics. Well-defined mental states provide contexts inducing a criterion of structural stability for the neurodynamics that can be implemented by particular partitions. This leads to distinguished subshifts of finite type that are eithe

Max Shpak, Stephen Proulx

For two genotypes that have the same mean number of offspring but differ in the variance in offspring number, natural selection will favor the genotype with lower variance. The concept of fitness becomes cloudy under these conditions because the outcome of evolution is not deterministic. However, the effect of variance in offspring number on the fixation pro

L. J. M. Dunlop, G. F. Gribakin

When recent experimental positronium (Ps) formation cross sections in noble gases have been compared with the most up-to date theoretical studies, the agreement is qualitative, but not quantitative. In this paper we re-examine this process and show that at low energies Ps formation must be treated nonperturbatively. We also look at Ps formation with inner sh

L. J. M. Dunlop, G. F. Gribakin

A many-body theory approach to the calculation of gamma spectra of positron annihilation on many-electron atoms is developed. We evaluate the first-order correlation correction to the annihilation vertex and perform numerical calculations for the noble gas atoms. Extrapolation with respect to the maximal orbital momentum of the intermediate electron and posi

S. Esposito

We give, for the first time, the critical complete text of a manuscript by Ettore Majorana, conserved in the same file of the lecture notes for his course on Theoretical Physics at the University of Naples. He probably refers to a seminar delivered in that University. Some passages reveal a physical interpretation of the Quantum Mechanics which anticipates o

K. Doll, R. Dovesi, R. Orlando

Analytical Hartree-Fock gradients with respect to the cell parameter have been implemented in the electronic structure code CRYSTAL, for the case of one and two-dimensional periodicity. As in most molecular codes, Gaussian type orbitals are used to express the wavefunction. Examples demonstrate that the gradients have a good accuracy.

M. Goncharov, T. Kamon, V. Khotilovich, V. Krutelyov

We report on the design and performance of the electromagnetic calorimeter timing readout system (EMTiming) for the Collider Detector at Fermilab (CDF). The system will be used in searches for rare events with high energy photons to verify that the photon is in time with the event collision, to reject cosmic ray and beam halo backgrounds, and to allow direct

Robert M. Hamwey

This study explores the potential to enhance the reflectance of solar insolation by the human settlement and grassland components of the Earth&#39;s terrestrial surface as a climate change mitigation measure. Preliminary estimates derived using a static radiative transfer model indicate that such efforts could amplify the planetary albedo enough to offset th

V. Kulkarni, N. Deo

We examine volatility of an Indian stock market in terms of aspects like participation, synchronization of stocks and quantification of volatility using the random matrix approach. Volatility pattern of the market is found using the BSE index for the three-year period 2000-2002. Random matrix analysis is carried out using daily returns of 70 stocks for sever

Martin Castelnovo, Alex Evilevitch

The classical Gibbs-Donnan equilibrium describes excess osmotic pressure associated with confined colloidal charges embedded in an electrolyte solution. In this work, we extend this approach to describe the influence of multivalent ion binding on the equilibrium force acting on a charged rod translocating between two compartments, thereby mimicking ionic eff

G. F. Gribakin, C. M. R. Lee

In this paper we use a zero-range potential (ZRP) method to model positron interaction with molecules. This allows us to investigate the effect of molecular vibrations on positron-molecule annihilation using the van der Waals dimer Kr2 as an example. We also use the ZRP to explore positron binding to polyatomics and examine the dependence of the binding ener

Eef van Beveren, Frieder Kleefeld, George Rupp

We describe light-reflection properties of spherically curved mirrors, like balls in the Christmas tree. In particular, we study the position of the image which is formed somewhere beyond the surface of a spherical mirror, when an eye observes the image of a pointlike light source. The considered problem, originally posed by Abu Ali Hasan Ibn al-Haitham -- a

A. N. Ivanov, M. Faber, V. A. Ivanova, J. Marton

Using the experimental data on the energy level shift of kaonic hydrogen in the ground state (the DEAR Collaboration, Phys. Rev. Lett. 94, 212302 (2005)) and the theoretical value of the energy level shift, calculated within the phenomenological quantum field theoretic approach to the description of strong low-energy anti-K N and anti-K NN interactions devel

V. V. Begun, L. Ferroni, M. I. Gorenstein, M. Gazdzicki

Particle multiplicities and ratios in the microcanonical ensemble of relativistic gases near production thresholds are studied. It is shown that the ratio of heavy to light particle multiplicity may be enhanced in comparison to its thermodynamic limit.

Tim Van Cauteren, Jan Ryckebusch, Bernard C. Metsch, Herbert-R. Petry

We present results for the helicity amplitudes of the lowest-lying hyperon resonances Y*, computed within the framework of the Bonn constituent-quark model, which is based on the Bethe-Salpeter approach. The seven parameters entering the model are fitted against the best known baryon masses. Accordingly, the results for the helicity amplitudes are genuine pr

Q. L. Wang, L. Dang, X. H. Zhong, P. Z. Ning

The $Λ$- and $Ξ^-$-hyperon mean free paths in nuclei are firstly calculated in the relativistic mean field (RMF) theory. The real parts of the optical potential are derived from the RMF approach, while the imaginary parts are obtained from those of nucleons with the relations: $U^{\mathrm{IY}}_{\mathrm{S}} = α_{σ\mathrm{Y}}\cdot U_{\mathrm{S}}^{\mathrm{IN}}$

J. M. Cook, T. Glasmacher, A. Gade

The method of intermediate-energy Coulomb excitation has been widely used to determine absolute B(E2; 0+ -> 2+) quadrupole excitation strengths in exotic nuclei with even numbers of protons and neutrons. Transition rates measured with intermediate-energy Coulomb excitation are compared to their respective adopted values and for the example of 26Mg to the B(E

A. Guertin, S. Auduc, G. Rivière, P. Eudes

Double differential cross sections (DDCS) for light charged particles (proton, deuteron, triton, 3He, alpha) and neutrons produced by a proton beam impinging on a 238U target at 62.9 MeV were measured at the CYCLONE facility in Louvain-la-Neuve (Belgium). These measurements have been performed using two independent experimental set-ups ensuring neutron (DeMo

R. Carretero-Gonzalez, J. D. Talley, C. Chong, B. A. Malomed

We analyze the existence and stability of localized solutions in the one-dimensional discrete nonlinear Schrödinger (DNLS) equation with a combination of competing self-focusing cubic and defocusing quintic onsite nonlinearities. We produce a stability diagram for different families of soliton solutions, that suggests the (co)existence of infinitely many bra

Karina Laneri, Alejandro F. Rozenfeld, Ezequiel V. Albano

A dynamic scaling Ansatz for the approach to the Self-Organized Critical (SOC) regime is proposed and tested by means of extensive simulations applied to the Bak-Sneppen model (BS), which exhibits robust SOC behavior. Considering the short-time scaling behavior of the density of sites ($ρ(t)$) below the critical value, it is shown that i) starting the dynami

Nataliya Gorbatova, Oleg Kiselev, Sergei Glebov

We construct a special asymptotic solution for the forced Boussinesq equation. The perturbation is small and oscillates with a slowly varied frequency. The slow passage through the resonance generates waves with the finite amplitude. This phenomenon is described in details.

David Chavalarias

Aggregated phenomena in social sciences and economics are highly dependent on the way individuals interact. To help understanding the interplay between socio-economic activities and underlying social networks, this paper studies a sequential prisoner&#39;s dilemma with binary choice. It proposes an analytical and computational insight about the role of endog

C. A. Vaquera-Araujo, J. L. Lucio M

We formulate non-relativistic classical and quantum mechanics in the non-commutative two dimensional plane. The approach we use is based on the Galilei group, where the non-commutativity is seen as a central extension upon identification of the boost generators with the position operator. We perform a systematic study of the free particle, defined by the sym

Greg E. Knese

There is a known generalization of the classical Schwarz lemma to holomorphic functions from the polydisk to the disk. In this paper, we characterize those functions which satisfy equality everywhere in this generalized inequality: they are the transfer function of an n+1 by n+1 symmetric unitary, and in particular, are rational, inner, and belong to the Sch

Y. Safarov

The paper extends Birkhoff&#39;s theorem on doubly stochastic matrices to some countable families of discrete probability spaces with nonempty intersections. We join every two elements lying in the same probability space by an edge and formulate our results in terms of the obtained graph.

Ana Marco, Jose-Javier Martinez

A nonstandard application of bivariate polynomial interpolation is discussed: the implicitization of a rational algebraic curve given by its parametric equations. Three different approaches using the same interpolation space are considered, and their respective computational complexities are analyzed. Although the techniques employed are usually asociated to

Ana Marco, Jose-Javier Martinez

The approach to curve implicitization through Sylvester and Bezout resultant matrices and bivariate interpolation in the usual power basis is extended to the case of Bernstein-Bezoutian matrices constructed when the polynomials are given in the Bernstein basis. The coefficients of the implicit equation are also computed in the bivariate tensor-product Bernst

Stephan Baier

We prove that the conditions $λ<5/19$ and $L\le T^{1/2}$ in Theorems 3 and 4 of our recent paper &#34;On the $p^λ$ problem&#34; can be omitted.

Peter A. Linnell, Gena Puninski, Patrick F. Smith

We prove that every non-finitely generated projective module over the integral group ring of a polycyclic-by-finite group G is free if and only if G is polycyclic.

Stephan Baier

We deal with the distribution of the fractional parts of $p^λ$, $p$ running over the prime numbers and $λ$ being a fixed real number lying in the interval $(0,1)$. Roughly speaking, we study the following question: Given a real $θ$, how small may $δ>0$ be choosen if we suppose that the number of primes $p\le N$ satisfying ${p^λ-θ<δ}$ is close to the expected

Elena Klimenko, Natalia Kopteva

We describe all real points of the parameter space of two-generator Kleinian groups with a parabolic generator, that is, we describe a certain two-dimensional slice through this space. In order to do this we gather together known discreteness criteria for two-generator groups and present them in the form of conditions on parameters. We complete the descripti

Paavo Salminen, Pierre Vallois

The joint distribution of maximum increase and decrease for Brownian motion up to an independent exponential time is computed. This is achieved by decomposing the Brownian path at the hitting times of the infimum and the supremum before the exponential time. It is seen that an important element in our formula is the distribution of the maximum decrease for t

Paul Sablonniere

We study a new simple quadrature rule based on integrating a $C^1$ quadratic spline quasi-interpolant on a bounded interval. We give nodes and weights for uniform and non-uniform partitions. We also give error estimates for smooth functions and we compare this formula with Simpson&#39;s rule.