December 2003 arXiv papers — page 9

Mira Mandeljc, Marija Kosec, S. P. Gabuda, S. G. Kozlova

Thin films of zirconium-rich perovskites Pb1-3x/2 Lax Zr0.65 Ti0.35O3 (PLZT; x=0.095) were studied using X-ray absorption near-edge structure (XANES) spectroscopy. Is shown, that slow crystallization of the system is accompanied by partial reduction of lead oxides to a metal (Pb0) state. The same results were found in the samples of the same composition with

Roland Kay, Neil F. Johnson

We present a detailed discussion of the role played by memory, and the nature of self-induced shocks, in an evolutionary population competing for limited resources. Our study builds on a previously introduced multi-agent system [Phys. Rev. Lett 82, 3360 (1999)] which has attracted significant attention in the literature. This system exhibits self-segregation

M. A. Yurishchev

Using transfer-matrix extended phenomenological renormalization-group methods [M.A.Yurishchev, Nucl. Phys. B (Proc. Suppl.) 83-84, 727 (2000); hep-lat/9908019; J. Exp. Theor. Phys. 91, 332 (2000); cond-mat/0108002] the improved estimates for the critical temperature of spin-1/2 Ising model on a simple-cubic lattice with partly anisotropic coupling strengths

Jae-Hyeon Eom, Sung-Sik Lee, Ki-Seok Kim, Sung-Ho Suck Salk

An improved version of SU(2) slave-boson approach is applied to study the in-plane optical conductivity of the two dimensional systems of high Tc cuprates. We investigate the role of fluctuations of both the phase and amplitude of order parameters on the (Drude) peak-dip-hump structure in the in-plane conductivity as a function of hole doping concentration a

I. Siddiqi, R. Vijay, F. Pierre, C. M. Wilson

We performed a novel phase sensitive microwave reflection experiment which directly probes the dynamics of the Josephson plasma resonance in both the linear and non-linear regime. When the junction was driven below the plasma frequency into the non-linear regime, we observed for the first time the transition between two different dynamical states predicted f

D. P. Kirilova

The observational and theoretical status of neutrino oscillations in connection with solar and atmospheric neutrino anomalies is presented in brief. The effect of neutrino oscillations on the early Universe evolution is discussed in detail. A short review is given of the standard Big Bang Nucleosynthesis and the influence of resonant and nonresonant neutrino

P. Kaaret, A. Alonso-Herrero, J. S. Gallagher, G. Fabbiano

We examine the spatial offsets between X-ray point sources and star clusters in three starburst galaxies. We find that the X-ray sources are preferentially located near the star clusters. Because the star clusters are very good tracers of the star formation activity in the galaxies, this indicates that the X-ray sources are young objects associated with curr

G. M. Karataeva, I. O. Drozdovsky, V. A. Hagen-Thorn, V. A. Yakovleva

We present the results of stellar photometry of polar-ring galaxies NGC 2685 and NGC 4650A, using the archival data obtained with the Hubble Space Telescope's Wide Field Planetary Camera 2. Polar rings of these galaxies were resolved into ~800 and ~430 stellar objects in the B, V and Ic bands, considerable part of which are blue supergiants located in th

Peter T. Williams

We have argued that magnetohydrodynamic (MHD) turbulence in an accretion disk naturally produces hoop-stresses, and that in a geometrically-thick flow these stresses could both drive and collimate an outflow. We based this argument on an analogy of turbulent MHD fluids to viscoelastic fluids, in which azimuthal shear flow creates hoop-stresses that cause a v

B. J. Pearson, P. H. Bucksbaum

We explore coherent control of stimulated Raman scattering in the nonimpulsive regime. Optical pulse shaping of the coherent pump field leads to control over the stimulated Raman output. A model of the control mechanism is investigated.

André van Tonder, Miquel Dorca

This preprint has been withdrawn.

Astrid S. de Wijn, Henk van Beijeren

In this paper, we demonstrate how the Lyapunov exponents close to zero of a system of many hard spheres can be described as Goldstone modes, by using a Boltzmann type of approach. At low densities, the correct form is found for the wave number dependence of the exponents as well as for the corresponding eigenvectors in tangent-space. The predicted values for

X. Bekaert, I. L. Buchbinder, A. Pashnev, M. Tsulaia

We briefly review some modern developments in higher spin field theory and their links with superstring theory. The analysis is based on various BRST constructions allowing to derive the Lagrangians for massive and massless higher spin fields on flat or constant curvature backgrounds of arbitrary dimensions.

H. Watanabe, S. Yukawa, M. A. Novotny, N. Ito

We construct a rejection-free Monte Carlo method for the hard-disk system. Rejection-free Monte Carlo methods preserve the time-evolution behavior of the standard Monte Carlo method, and this relationship is confirmed for our method by observing nonequilibrium relaxation of a bond-orientational order parameter. The rejection-free method gives a greater compu

Edgar Bugaev, Teresa Montaruli, Yuri Shlepin, Igor Sokalski

If muon neutrinos produced in cosmological sources oscillate, neutrino telescopes can have a chance to detect tau-neutrinos. In contrast to muon neutrinos the Earth is completely transparent for tau neutrinos thanks to the short life time of tau-leptons produced in charged current interactions. Tau-lepton decaysin flight producing another tau neutrino (regen

The Jefferson Lab Hall A Collaboration, S. Jaminion

Virtual Compton Scattering is studied at the Thomas Jefferson National Accelerator Facility at low Center-of-Mass energies, below pion threshold. Following the Low Energy Theorem for the $ ep \to ep γ$ process, we obtain values for the two structure functions Pll-Ptt/epsilon and Plt at four-momentum transfer squared Q2=0.92 and 1.76 GeV2.

Y. Fujiwara, Y. Suzuki, M. Kohno

The 3 alpha orthogonality condition model using the Pauli-forbidden bound states of the Buck, Friedlich and Wheatly alpha alpha potential can yield a compact 3 alpha ground state with a large binding energy, in which a small admixture of the redundant components can never be eliminated.

Akira Kitagawa, Katsuji Yamamoto

We analyze the linear optical realization of number-sum Bell measurement and number-state manipulation by taking into account the realistic experimental situation, specifically imperfectness of single-photon detector. The present scheme for number-state manipulation is based on the number-sum Bell measurement, which is implemented with linear optical element

Emanuel Katz, Jaeyong Lee, Ann E. Nelson, Devin G. E. Walker

We describe a natural UV complete theory with a composite little Higgs. Below a TeV we have the minimal Standard Model with a light Higgs, and an extra neutral scalar. At the TeV scale there are additional scalars, gauge bosons, and vector-like charge 2/3 quarks, whose couplings to the Higgs greatly reduce the UV sensitivity of the Higgs potential. Stabiliza

S. Hamieh

In this note we discuss the effect of the unpolarized state in the spin-correlation measurement of the $^1S_0$ two-proton state produced in 12C(d,2He) reaction at the KVI, Groningen. We show that in the presence of the unpolarized state the maximal violation of the CHSH-Bell inequality is lower than the classical limit if the purity of the state is less than

Dagomir Kaszlikowski, Jenn Yang Lim, Leong Chuang Kwek, Berthold-Georg Englert

The security of a cryptographic key that is generated by communication through a noisy quantum channel relies on the ability to distill a shorter secure key sequence from a longer insecure one. We show that -- for protocols that use quantum channels of any dimension and completely characterize them by state tomography -- the noise threshold for classical adv

Alex D. Gottlieb

This note introduces some examples of quantum random walks in d-dimensional Eucilidean space and proves the weak convergence of their rescaled n-step densities. One of the examples is called the Plancherel quantum walk because the "quantum coin flip" is the Fourier Integral (or Plancherel) Transform. The other examples are the Birkhoff quantum walks,

S. N. Volkov

The approach for the description of the DNA conformational transformations on the mesoscopic scales in the frame of the double helix is presented. Due to consideration of the joint motions of DNA structural elements along the conformational pathways the models for different transformations may be constructed in the unifying two-component form. One component

Stephen Jewson

We investigate the relationships between weather forecasting, weather derivatives, the Black-Scholes equation, Feynmann-Kac theory and the Fokker-Planck equation. There is one useful result, but on the whole the relations we present seem to be more interesting than practically useful.

Kaspars Blushs, Marcis Auzinsh

In this paper we, to our knowledge, for the first time obtain the rate equations for Zeeman coherences in the broad line approximation and steady-state balance equations directly from optical Bloch equations without the use of the perturbation theory. The broad line approximation allows us to use the adiabatic elimination procedure in order to eliminate the

Alexei Yu. Illarionov

We compute the distribution of quasideuterons in doubly closed shell nuclei and infinite correlated nuclear matter. The ground states of $^{16}$O and $^{40}$Ca are described in $ls$ coupling using a realistic hamiltonian including the Argonne $v_{8}^\prime$ and the Urbana IX models of two-- and three--nucleon potentials, respectively. The nuclear wave functi

T. Falter, J. Lehr, U. Mosel, P. Muehlich

We first briefly review the theoretical basis for calculations of changes of hadronic properties in dense nuclear matter. These changes have usually been investigated by means of relativistic heavy-ion reactions. Here we discuss that observable consequences of such changes can also be seen in more elementary reactions on nuclei. Particular emphasis is put on

Chaejun Song

We solve Schwinger-Dyson (SD) equation for the color superconducting (CS) gap in nonlocal gauge which justifies the ladder approximation in subleading order calculation. The gap prefactor increases about 1.6 times to the leading order gap determined in Landau gauge.

Fatihcan M. Atay

Coupled oscillators are shown to experience amplitude death for a much larger set of parameter values when they are connected with time delays distributed over an interval rather than concentrated at a point. Distributed delays enlarge and merge death islands in the parameter space. Furthermore, when the variance of the distribution is larger than a threshol

A. K. Kwasniewski

A calculus of sequences started in 1936 opened the way for future extensions of umbral calculus in its finite operator form. Because of historically established notation we call it the psi-calculus.It appears in parts to be almost automatic extension of the standard classical finite operator calculus.

Viacheslav V. Nikulin, Sachiko Saito

Classification of real K3 surfaces X with a non-symplectic involution \tau is considered. For some exactly defined and one of the weakest possible type of degeneration (giving the very reach discriminant), we show that the connected component of their moduli is defined by the isomorphism class of the action of \tau and the anti-holomorphic involution \phi in

Meinolf Geck

Following Lusztig, we consider a Coxeter group $W$ together with a weight function $L$. This gives rise to the pre-order relation $\leq_{L}$ and the corresponding partition of $W$ into left cells. We introduce an equivalence relation on weight functions such that, in particular, $\leq_{L}$ is constant on equivalent classes. We shall work this out explicitly

Albrecht Boettcher, Harold Widom

We present two elementary derivations of the formula for the Toeplitz determinant generated by a pure Fisher-Hartwig singularity.

Nicoletta Cantarini, Giovanna Carnovale, Mauro Costantini

Let $U_ε(\mathfrak g)$ be the simply connected quantized enveloping algebra associated to a finite-dimensional complex simple Lie algebra $\mathfrak g$ at the roots of unity. The De Concini-Kac-Procesi conjecture on the dimension of the irreducible representations of $U_ε(\mathfrak g)$ is proved for representations corresponding to the spherical conjugacy cl

Masato Tsujii

We consider dynamical systems generated by partially hyperbolic surface endomorphisms of class C^r with one-dimensional strongly unstable subbundle. As the main result, we prove that such a dynamical system generically admits finitely many ergodic physical measures whose union of basins of attraction has total Lebesgue measure, provided that r>= 19.

H. K. Jassal

We study some cosmological consequences of the five dimensional, two brane Randall-Sundrum scenario. We integrate over the extra dimensions and in four dimensions the action reduces to that of scalar tensor gravity. The radius of the compact extra dimension is taken to be time dependent.It is shown that the radius of the extra dimension rapidly approaches a

Chao-Hsi Chang, Jiao-Kai Chen, Guo-Li Wang

The instantaneous formulations for the relativistic Bethe-Salpeter (BS) and the radiative transitions between the bound-states are achieved if the BS kernel is instantaneous. It is shown that the original Salpeter instantaneous equation set up on the BS equation with an instantaneous kernel should be extended to involve the `small (negative energy) component

M. Faber, A. N. Ivanov

We calculate the most general effective potential for the massless Thirring model in dependence of the local fields of all fermion-antifermion collective excitations. We analyse the minima of this potential describing different vacua of the quantum system. We confirm the existence of the absolute minimum found in EPJC 20, 723 (2001) corresponding to the chir

Hans-Christian Pauli

The general equation from previous work is specialized to a quadratic potential $V(r)=-a+\frac12 f r^2$ acting in the space of spherically symmetric S wave functions. The fine and hyperfine interaction creates then a position dependent mass $\widetilde m(r)$ in the effective kinetic energy of the associated Schrödinger equation. The results are compared with

Hans-Christian Pauli

The general equation from previous work is specialized to a linear potential $V(r)=-a+F r$ acting in the space of spherically symmetric S wave functions. The fine and hyperfine interaction creates then a $\frac1r$-dependence in the effective potential energy equation and a position dependent mass $\widetilde m(r)$ in the effective kinetic energy of the assoc

Hans-Christian Pauli

The formalism for the spin interactions in the front form (light-cone) is re-phrased in terms of an instant form formalism. It is shown how to unitarily transform the Brodsky-Lepage spinors to Bjørken-Drell spinors and to re-phrase the so called spinor matrix in terms of the interactions one is familiar with from atomic and Dirac theory. -- One retrieves the

Ashok Goyal

It is believed that quark stars or neutron stars with mixed phase in the core have smaller radii compared to ordinary compact stars. With the recent observation of several low radius objects, typically a radius of $<10 Km.$ for star of mass $< 1M_0$ in low mass X-ray binaries (LMXB), it has become very important to understand the nature of these objects. An

The Jefferson Lab Hall A Collaboration, G. Laveissiere

Virtual Compton Scattering is studied at the Thomas Jefferson National Accelerator Facility in the energy domain below pion threshold and in the Delta(1232) resonance region. The data analysis is based on the Dispersion Relation (DR) approach. The electric and magnetic Generalized Polarizabilities (GPs) of the proton and the structure functions Pll-Ptt/epsil

Harry J. Lipkin

The apparent symmetry between energy and momentum found in all covariant descriptions of neutrino oscillations is destroyed in the neutrino detector, a quantum mechanical system described by a density matrix diagonal in energy but not in momentum. The off diagonal matrix elements between states of different momenta and the same energy produce the coherence a

Hans-Christian Pauli

The long standing problem of a non-perturbative renormalization of a gauge field theoretical Hamiltonian is addressed and explicitly carried out within an (effective) light-cone Hamiltonian approach to QCD. The procedure is in line with the conventional ideas: The Hamiltonian is first regulated by suitable cut-off functions, and subsequently renormalized by

B. Aubert, BABAR Collaboration

We present measurements of branching fractions and \CP-violating asymmetries in decays of $B$ mesons to two-body final states containing a \Kz. The results are based on a data sample of approximately 88 million \upsbb decays collected with the \babar detector at the \pep2 asymmetric-energy $B$ Factory at SLAC. We measure $\BR(\Bp\to\Kz\pip) = (22.3 \pm 1.7 \

Beverly K. Berger

Heuristic arguments and numerical simulations support the Belinskii et al (BKL) claim that the approach to the singularity in generic gravitational collapse is characterized by local Mixmaster dynamics (LMD). Here, one way to identify LMD in collapsing spatially inhomogeneous cosmologies is explored. By writing the metric of one spacetime in the standard var

V. Husain, O. Winkler

We examine the singularity resolution issue in quantum gravity by studying a new quantization of standard Friedmann-Robertson-Walker geometrodynamics. The quantization procedure is inspired by the loop quantum gravity programme, and is based on an alternative to the Schrödinger representation normally used in metric variable quantum cosmology. We show that i

Joseph Y. Halpern, Daphne Koller

Non-deductive reasoning systems are often {\em representation dependent}: representing the same situation in two different ways may cause such a system to return two different answers. Some have viewed this as a significant problem. For example, the principle of maximum entropy has been subjected to much criticism due to its representation dependence. There

Juan-J. Merelo-Guervos, Beatriz Prieto, Fatima Rateb, Fernando Tricas

Websites of a particular class form increasingly complex networks, and new tools are needed to map and understand them. A way of visualizing this complex network is by mapping it. A map highlights which members of the community have similar interests, and reveals the underlying social network. In this paper, we will map a network of websites using Kohonen&#3

L. Panina, S. Sandacci, D. Makhnovskiy

In this research project we propose a new composite medium, which can visualise the mechanical stress at any stage: before and after damage. The main feature of the proposed stress-tuneable composite is its permittivity (dielectric constant), which depends on the mechanical stress. This kind of composite material can be characterised as a &#34;sensing medium

Jing Guo, Supriyo Datta, Mark Lundstrom, M. P. Anantam

Multiscale simulation approaches are needed in order to address scientific and technological questions in the rapidly developing field of carbon nanotube electronics. In this paper, we describe an effort underway to develop a comprehensive capability for multiscale simulation of carbon nanotube electronics. We focus in this paper on one element of that hiera

G. Falci, E. Paladino, R. Fazio

A high degree of quantum coherence is a crucial requirement for the implementation of quantum logic devices. Solid state nanodevices seem particularly promising from the point of view of integrability and flexibility in the design. However decoherence is a serious limitation, due to the presence of many types low energy excitations in the ``internal&#39;&#39

H. O. Wijewardane, C. A. Ullrich

We present a study of the nonlinear intersubband (ISB) response of conduction electrons in a GaAs/AlGaAs quantum well to strong THz radiation, using a density-matrix approach combined with time-dependent density-functional theory. We demonstrate coherent control of ISB optical bistability, using THz control pulses to induce picosecond switching between the b

Takayuki Mizuno, Tohur Nakano, Misako Takayasu, Hideki Takayasu

We introduce an autoregressive-type model of prices in financial market taking into account the self-modulation effect. We find that traders are mainly using strategies with weighted feedbacks of past prices. These feedbacks are responsible for the slow diffusion in short times, apparent trends and power law distribution of price changes.

Yongqiang Xue, Mark A. Ratner

Electronic properties of metal-finite semiconducting carbon nanotube interfaces are studied as a function of the nanotube length using a self-consistent tight-binding theory. We find that the shape of the potential barrier depends on the long-range tail of the charge transfer, leading to an injection barrier thickness comparable to half of the nanotube lengt

Peter L. Gonthier, Robert Van Guilder, Alice K. Harding

We present results of a pulsar population synthesis study that incorporates a number of recent developments and some significant improvements over our previous study. We have included the results of the Parkes multi-beam pulsar survey in our select group of nine radio surveys, doubling our sample of radio pulsars. We adopted with some modifications the radio

L. V. Shalyapina, A. V. Moiseev, V. A. Yakovleva, V. A. Hagen-Thorn

(abridged)We present the observations of the pair of interacting galaxies NGC6285/86 carried out with the 6m SAO RAS telescope by using 1D and 2D spectroscopy. The observations of NGC6286 with a long-slit spectrograph (UAGS) near the H-alpha line revealed the rotation of the gaseous disk around an axis offset by 5&#39;&#39;-7&#39;&#39; from the photometric c

Pasquale Blasi

The detection of cosmic rays with energy around and in excess of $10^{20}$ eV raises many questions that future experiments will help answering to. I address here my view of some of these open issues, as they are now and as they might be affected by future observations.

D. Gittins, C. Clarke

We present a new method for estimating the corotation radius in tightly wound spiral galaxies, through analysis of the radial variation of the offset between arms traced by the potential (P-arms) and those traced by dust (D-arms). We have verified the predictions of semi-analytical theory through hydrodynamical simulations and have examined the uniqueness of

K. Werner, T. Nagel, S. Dreizler, T. Rauch

We report on first results of computing synthetic spectra from H/He-poor accretion disks in ultracompact LMXBs. We aim at the determination of the chemical composition of the very low-mass donor star, which is the core of a former C/O white dwarf. The abundance analysis allows to draw conclusions on gravitational settling in WDs which is an important process

Dipanjan Mitra, X. H. Li

We use a set of carefully selected published average multifrequency polarimetric observations for six bright cone dominated pulsars and devise a method to combine the multifrequency polarization position angle (PPA) sweep traverses. We demonstrate that the PPA traverse is in excellent agreement with the rotating vector model over this broad frequency range c

S. Degl&#39;Innocenti, G. Fiorentini, B. Ricci, F. L. Villante

We discuss implications of a new measurement of $^{14}N(p, γ)^{15}O$ concerning solar neutrinos, solar models and globular cluster dating. Predictions for the gallium and chlorine experiments are reduced by 2 and 0.1 SNU respectively. Predictions for helioseismic observables are unchanged within uncertainties. The age of globular clusters as deduced from the

Teresa Montaruli

Astroparticle physics is a field rich of perspectives in investigating the ultra-high energy region which will never be accessible to man made machines. Many efforts are underway in order to detect the first cosmic neutrinos, messengers of the unobserved universe. The motivations of this field of research, the current and next future experimental status are

W. Zheng, G. A. Kriss, J. -M. Deharveng, W. V. Dixon

We obtained high-resolution VLT and FUSE spectra of the quasar HE2347-4342 to study the properties of the intergalactic medium between redshifts z=2.0-2.9. The high-quality optical spectrum allows us to identify approximately 850 HeII absorption components with column densities between N~5X10^11 and $ 10^18 cm^-2. The reprocessed FUSE spectrum extends the wa

Youichi Ohyama, Yoshiaki Taniguchi

We report results of our new spatially-resolved, optical spectroscopy of the giant Ly$α$ nebula around a powerful radio galaxy 1243+036 (4C+03.24) at $z=3.57$. The nebula is extended over $\sim 30$ kpc from the nucleus, and forms a pair of cones or elongated bubbles. The high-velocity ($\sim -1000$ km s$^{-1}$; blueshifted with respect to the systemic veloci

Cristin J. Rider, Douglas L. Tucker, J. Allyn Smith, Chris Stoughton

We present initial results of a photometric survey of open star clusters, primarily in the southern hemisphere, taken in the u&#39;g&#39;r&#39;i&#39;z&#39; filter system. While our entire observed sample covers more than 100 clusters, here we present data for NGC2548 (M48) which is a cluster characterized in the UBV and DDO photometric systems. We compare ou

Eric J. Murphy, Pierre Demarque, D. B. Guenther

We present a preliminary theoretical seismic study of the astronomically famous star 51 Peg. This is done by first performing a detailed analysis within the Hertzsprung-Russell diagram (HRD). Using the Yale stellar evolution code (YREC), a grid of stellar evolutionary tracks has been constructed for the masses 1.00 M_sun, 1.05 M_sun and 1.10 M_sun, in the me

B. C. Lee, S. S. Allam, D. L. Tucker, J. Annis

Compact groups (CGs) of galaxies -- relatively poor groups of galaxies in which the typical separations between members is of the order of a galaxy diameter -- offer an exceptional laboratory for the study of dense galaxian environments with short (<1Gyr) dynamical time-scales. In this paper, we present an objectively defined catalog of CGs in 153 sq deg of

Melanie Freed, Philip M. Hinz, Michael R. Meyer

We plan to take advantage of the unprecedented combination of low thermal background and high resolution provided by the 6.5m MMT&#39;s adaptive secondary mirror, to target the 3-5 micron atmospheric window where giant planets are expected to be anomalously bright. We are in the process of building a 3-5 micron coronograph that is predicted to be sensitive t

A. Spallicci, A. Morbidelli, G. Metris

The Hannay angle has been previously studied for a celestial circular restricted three-body system by means of an adiabatic approach. In the present work, three main results are obtained. Firstly, a formal connection between perturbation theory and the Hamiltonian adiabatic approach shows that both lead to the Hannay angle; it is thus emphasised that this ef

Hwang Lee, Pieter Kok, Colin P. Williams, Jonathan P. Dowling

The working principles of linear optical quantum computing are based on photodetection, namely, projective measurements. The use of photodetection can provide efficient nonlinear interactions between photons at the single-photon level, which is technically problematic otherwise. We report an application of such a technique to prepare quantum correlations as

Eugene I. Chiang, Ruth A. Murray-Clay

The light curves of the pre-main-sequence star KH 15D from the years 1913--2003 can be understood if the star is a member of an eccentric binary that is encircled by a vertically thin, inclined ring of dusty gas. Eclipses occur whenever the reflex motion of a star carries it behind the circumbinary ring; the eclipses occur with period equal to the binary orb

Darren Reed, Fabio Governato, Licia Verde, Jeffrey Gardner

We use numerical simulations in a Lambda CDM cosmology to model density profiles in a set of 16 dark matter haloes with resolutions of up to 7 million particles within the virial radius. These simulations allow us to follow robustly the formation and evolution of the central cusp over a large mass range of 10^11 to 10^14 M_sun, down to approximately 0.5% of

Alexey Boyarsky, Bogdan Kulik, Oleg Ruchayskiy

Interpretation of D1 and D0-branes in 1+1 string theory as classical and quantum eigen-values in dual c=1 Matrix Quantum Mechanics (MQM) was recently suggested. MQM is known to be equivalent to a system of N free fermions (eigen-values). By considering quantum mechanics of fermions in the presence of classical eigen-value we are able to calculate explicitly

K. S. Babu, Gerhart Seidl

We formulate a set of naturalness criteria for sterile neutrinos (ν&#39;) to be light, needed for reconciling the LSND neutrino anomaly with the other neutrino data. A light sterile neutrino becomes as natural as the light active neutrinos if it carries quantum numbers of a chiral gauge symmetry broken at the TeV scale. The simplest such theory is shown to b

A. A. Blinkouski, A. K. Gorbatsievich

The classical observational cosmological tests (Hubble diagram, count of sources, etc.) are considered for a homogeneous and isotropic model of the Universe in the framework of the five-dimensional Projective Unified Field Theory in which gravitation is described by both space-time curvature and some hypothetical scalar field (sigma-field). It is shown that

M. Gilfanov, H-J. Grimm, R. Sunyaev

We study the statistical properties of the combined emission of a population of discrete sources (e.g. X-ray emission of a galaxy due to its X-ray binaries population). Namely, we consider the dependence of their total luminosity L_tot=SUM(L_k) and of fractional rms_tot of their variability on the number of sources N or, equivalently, on the normalization of

Harvey B. Meyer

We investigate in detail a 2-level algorithm for the computation of 2-point functions of fuzzy Wilson loops in lattice gauge theory. Its performance and the optimization of its parameters are described in the context of 2+1D SU(2) gluodynamics. In realistic calculations of glueball masses, it is found that the reduction in CPU time for given error bars on th

Arkadiusz Jadczyk

It is shown that piecewise deterministic dissipative quantum dynamics in a vector space with indefinite metric can lead to well defined, positive probabilities. The case of quantum jumps on the Poincar&#39;e disk is studied in details, including results of numerical simulations of quantum fractals. Keywords: iterated function systems, dynamical semigroups, E

Mrinal Dasgupta, Gavin P. Salam

This article reviews the status of event-shape studies in e+e- annihilation and DIS. It includes discussions of perturbative calculations, of various approaches to modelling hadronisation and of comparisons to data.

S. Scholl, H. Weigel

We calculate the magnetic moments of heavy baryons with a single heavy quark in the bound-state approach. In this approach the heavy baryons is considered as a heavy meson bound in the field of a light baryon. The light baryon field is represented as a soliton excitation of the light pseudoscalar and vector meson fields. For these calculations we adopt a mod

B. Kyung, V. Hankevych, A. -M. Dare, A. -M. S. Tremblay

We present reliable many-body calculations for the t-t&#39;-t&#39;&#39;-U Hubbard model that explain in detail the results of recent angle-resolved photoemission experiments on electron-doped high-temperature superconductors. The origin of the pseudogap is traced to two-dimensional antiferromagnetic spin fluctuations whose calculated temperature dependent co

Dan Heyman, Franz Hinteleitner, Seth Major

Two theories of special relativity with an additional invariant scale, &#34;doubly special relativity&#34; (DSR), are tested with calculations of particle process kinematics. Using the Judes-Visser modified conservation laws, thresholds are studied in both theories. In contrast to some linear approximations, which allow for particle processes forbidden in sp

R. Guimera, S. Mossa, A. Turtschi, L. A. N. Amaral

We analyze the global structure of the world-wide air transportation network, a critical infrastructure with an enormous impact on local, national, and international economies. We find that the world-wide air transportation network is a scale-free small-world network. In contrast to the prediction of scale-free network models, however, we find that the most

Aurele Aubert

We consider four-dimensional massive gravity with the Fierz-Pauli mass term. The analysis of the scalar sector has revealed recently that this theory becomes strongly coupled above the energy scale Λ= (M_{Pl}^2 m^4)^{1/5} where m is the mass of the graviton. We confirm this scale by explicit calculations of the four-graviton scattering amplitude and of the l

Dongsu Bak, Ho-Ung Yee

We consider dimensional reduction of the lightlike holography of the covariant entropy bound from D+1 dimensional geometry of M X S to the D dimensional geometry M. With a warping factor, the local Bekenstein bound in D+1 dimensions leads to a more refined form of the bound from the D dimensional view point. With this new local Bekenstein bound, it is quite

V. Janis

We use real replicas within the Thouless, Anderson and Palmer construction to investigate stability of solutions with respect to uniform scalings in the phase space of the Sherrington-Kirkpatrick model. We show that the demand of homogeneity of thermodynamic potentials leads in a natural way to a thermodynamically dependent ultrametric hierarchy of order par

Caroline Champenois, Marie Houssin, Caroline Lisowski, Martina Knoop

We numerically evaluate the expected performances of an optical frequency standard at 729 nm based on a single calcium ion. The frequency stability is studied through the Allan deviation and its dependence on the excitation method (single Rabi pulse or two Ramsey pulses schemes) and the laser linewidth are discussed. The minimum Allan deviation that can be e

M. Amram, S. Ogata

In this paper we calculate fundamental groups (and some of their quotients) of complements of four toric varieties branch curves. For these calculations, we study properties and degenerations of these toric varieties and the braid monodromies of the branch curves in $\mathbb{CP}^2$. The fundamental groups related to the first three toric varieties turn to be

M. Aichhorn, M. Hohenadler, E. Ya. Sherman, J. Spitaler

We investigate charge ordering in the presence of electron-phonon coupling for quarter-filled ladder systems by using Exact Diagonalization. As an example we consider NaV2O5 using model parameters obtained from first-principles band-structure calculations. The relevant Holstein coupling to the lattice considerably reduces the critical value of the nearest-ne

Takaaki Imai, Yastoshi Takayama

We continue our study of the IIB matrix model on fuzzy $S^2 \times S^2$. Especially in this paper we focus on the case where the size of one of $S^2\times S^2$ is different from the other. By the power counting and SUSY cancellation arguments, we can identify the &#39;t Hooft coupling and large $N$ scaling behavior of the effective action to all orders. We c

David R. Underwood, Barrie W. Jones, P. Nick Sleep

A stellar evolution computer model has been used to determine changes in the luminosity L and effective temperature T(e) of single stars during their time on the main sequence. The range of stellar masses investigated was from 0.5 to 1.5 times that of the Sun, each with a mass fraction of metals (metallicity, Z) from 0.008 to 0.05. The extent of each star&#3

Jens Braun, Kai Schwenzer, Hans-Jürgen Pirner

We model the transition of a system of quarks and gluons at high energies to a system of quarks and mesons at low energies in a consistent renormalization group approach. Flow equations interpolate between the physics of the high-temperature degrees of freedom and the low-temperature dynamics at a scale of 1 GeV. We also discuss the dependence of the equatio

V. I. Komarov, H. Mueller, A. Sibirtsev

Data from KEK on subthreshold antiproton as well as on pi(+-) and K(+-) production in proton-nucleus reactions are described at projectile energies between 3.5 and 12.0 GeV. We use a model which considers a hadron-nucleus reaction as an incoherent sum over collisions of the projectile with a varying number of target nucleons. It samples complete events and a

P. S. Negi, M. C. Durgapal

We have obtained a criterion for spherically symmetric and static structures under hydrostatic equilibrium in general relativity (GR), which states that for a given value of $σ\equiv (P_0/E_0) \equiv $ the ratio of central pressure to central energy-density], the compaction parameter $u \equiv (M/a)$, where $M$ is the total mass and $a$ is the radius of the

H. Casini

The trace over the degrees of freedom located in a subset of the space transforms the vacuum state into a density matrix with non zero entropy. This geometric entropy is believed to be deeply related to the entropy of black holes. Indeed, previous calculations in the context of quantum field theory, where the result is actually ultraviolet divergent, have sh

Gian Pietro Pirola, Enrico Schlesinger

The uniform position principle states that, given an irreducible nondegenerate curve C in the projective r-space $P^r$, a general (r-2)-plane L is uniform, that is, projection from L induces a rational map from C to $P^1$ whose monodromy group is the full symmetric group. In this paper we show the locus of non-uniform (r-2)-planes has codimension at least tw

Heron Caldas

In this work we investigate the general properties and the ground state of an asymmetrical dilute gas of cold fermionic atoms, formed by two particle species having different densities. We have show in a recent paper, that a mixed phase composed of normal and superfluid components is the energetically favored ground state of such a cold fermionic system. Her

Jan de Gier, Pavel Pyatov

We diagonalise the Hamiltonian of the Temperley-Lieb loop model with open boundaries using a coordinate Bethe Ansatz calculation. We find that in the groundstate sector of the loop Hamiltonian, but not in other sectors, a certain constraint on the parameters has to be satisfied. This constraint has a natural interpretation in the Temperley-Lieb algebra with