May 2003 arXiv papers — page 22

Kyungsik Kim, Seong-Min Yoon

The multifractal behavior for tick data of prices is investigated in Korean financial market. Using the rescaled range analysis(R/S analysis), we show the multifractal nature of returns for the won-dollar exchange rate and the KOSPI. We also estimate the Hurst exponent and the generalized $q$th-order Hurst exponent in the unversal multifractal framework. Par

Augusto Gonzalez

A set of theoretical results [1-10] is reviewed, which concern calculations of energy spectra, density of energy levels, spin polarization, transport and optical properties (infrared absorption, luminescence) of semiconductor quantum dots and atomic traps. The studied systems contain a number of particles between 4 and 400, thus the calculation of their phys

M. Sabbane, M. Tij, A. Santos

The hierarchy of moment equations derived from the nonlinear Boltzmann equation is solved for a gas of Maxwell molecules undergoing a stationary Poiseuille flow induced by an external force in a pipe. The solution is obtained as a perturbation expansion in powers of the force (through third order). A critical comparison is done between the Navier-Stokes theo

F. K. Chow, H. F. Chau

In the original two-choice minority game (MG), selfish players cooperate with each other even though direct communication is not allowed. Moreover, there is a periodic dynamics in the MG whenever the strategy space size is much smaller than the number of strategies at play. Do these phenomena persist if every player has $N_c > 2$ choices where all player&#39

Peter Van

Some peculiarities of the exploitation of the entropy inequality in case of weakly nonlocal continuum theories are investigated and refined. As an example it is shown that the proper application of the Liu procedure leads to the Ginzburg-Landau equation in case of a weakly nonlocal extension of the constitutive space of the simplest internal variable theorie

Francis Halzen, Dan Hooper

We demonstrate that the South Pole kilometer-scale neutrino observatory IceCube can detect multi-TeV gamma rays continuously over a large fraction of the southern sky. While not as sensitive as pointing atmospheric Cerenkov telescopes, IceCube can roughly match the sensitivity of Milagro. Also, IceCube is complementary to Milagro because it will observe, wit

Elena Gallo, Rob Fender, Guy Pooley

We present a comprehensive study of (quasi-)simultaneous radio:X-ray observations of stellar black hole binaries during the spectrally hard X-ray state, finding evidence for a strong correlation between these two bands over more than three orders of magnitude in X-ray luminosity. The correlation extends from the quiescent regime up to close to the soft state

R. Pello, T. Contini, M. Lemoine-Busserolle, J. Richard

This paper reviews the most recent developments related to the use of lensing clusters of galaxies as Gravitational Telescopes in deep Universe studies. We summarize the state of the art and the most recent results aiming at studying the physical properties of distant galaxies beyond the limits of conventional spectroscopy. The application of photometric red

C. R. Mullis, B. R. McNamara, H. Quintana, A. Vikhlinin

We present the revised catalog of galaxy clusters detected as extended X-ray sources in the 160 Square Degree ROSAT Survey, including spectroscopic redshifts and X-ray luminosities for 200 of the 201 members. The median redshift is z~0.25 and the median X-ray luminosity is 4.2e+43 erg/s/h50^2 (0.5-2.0 keV). This is the largest high-redshift sample of X-ray s

Mariela Corti, Virpi Niemela, Nidia Morrell

From radial velocities derived from optical spectroscopic observations performed at CTIO, Chile, and CASLEO, Argentina, we have discovered that LSS 1135 is a single--lined O-type binary system with an orbital period of 2.7532 days. We present an analysis of the orbital elements of this system based on radial velocities of the He absorption lines. We classify

A. C. Katsiyannis, D. R. Williams, R. T. J. McAteer, P. T. Gallagher

One of the mechanisms proposed for heating the corona above solar active regions is the damping of magnetohydrodynamic (MHD) waves. Continuing on previous work, we provide observational evidence for the existence of high-frequency MHD waves in coronal loops observed during the August 1999 total solar eclipse. A wavelet analysis is used to identify twenty 4x4

P. Tozzi, P. Rosati, S. Ettori, S. Borgani

We present the analysis of the X-ray spectra of 18 distant clusters of galaxies with redshift 0.3 < z < 1.3. Most of them were observed with the Chandra satellite in long exposures ranging from 36 ks to 180 ks. For two of the z>1 clusters we also use deep XMM-Newton observations. Overall, these clusters probe the temperature range 3<kT<8 keV. Our analysis is

G. Kovács

By using the same algorithm in the Baade-Wesselink analyses of Galactic RR Lyrae and Cepheid variables, it is shown that, within 0.03 mag (1 sigma) statistical error, they yield the same distance modulus for the Large Magellanic Cloud. By fixing the zero point of the color-temperature calibration to those of the current infrared flux methods and using update

Simone Migliari, Rob Fender, Michael Rupen, Peter Jonker

We have analysed 12 simultaneous radio (VLA) and X-ray (RXTE) observations of the atoll-type X-ray binary 4U 1728-34, performed in two blocks in 2000 and 2001. We have found that the strongest and most variable emission seems to be associated with repeated transitions between hard (island) and softer (lower banana) X-ray states, while weaker, persistent radi

P. Haensel, J. L. Zdunik

Nuclear reactions in accreting neutron-star crusts and the heat release accompanying them are studied, under different assumptions concerning the composition of the outermost layer formed of the ashes of X-ray bursts. Particular examples of ashes containing nuclides with A ~ 90-110 are considered and compared with a standard A=56 case. In all cases, evolutio

Soma Mandal, Somenath Chakrabarty

It is shown explicitly using MIT bag model that in presence of ultra-strong magnetic fields, a nucleon either flattens or collapses in the direction transverse to the external magnetic field in the classical or quantum mechanical picture respectively. Which gives rise to some kind of mechanical instability. Alternatively, it is argued that the bag model of c

Steve Eales, Frank Bertoldi, Rob Ivison, Chris Carilli

We have observed 23 sources from the MAMBO 1200 micron survey with SCUBA at 850 microns, detecting 19 of the sources. The sources generally have low values for the ratio of 850 micron to 1200 micron flux. Two possible explanations for the low values are either that the sources are at very high redshift or that the global properties of the dust in the MAMBO s

Silvano Molendi, Stefano Bianchi, Giorgio Matt

We discuss the iron and nickel properties in the nuclear X-ray reflecting region of the Circinus Galaxy, studied with XMM-Newton. The main results are: a) from the depth of the Fe Kalpha edge, a value of A_Fe=1.7 in number with respect to the cosmic value (as for Anders & Grevesse 1989) is measured, if the (not directly visible) illuminating spectrum is assu

N. R. Napolitano, M. Pannella, M. Arnaboldi, O. Gerhard

We use a high resolution collisionless simulation of a Virgo--like cluster in a $Λ$CDM cosmology to determine the velocity and clustering properties of the diffuse stellar component in the intracluster region at the present epoch. The simulated cluster builds up hierarchically and tidal interactions between member galaxies and the cluster potential produce a

M. Plionis, C. Benoist, S. Maurogordato, C. Ferrari

We present indications, based on a sample of 303 Abell clusters, for a relation between the dynamical state of clusters and the alignments of galaxy members with their parent cluster major axis orientation as well as with the large scale environment within which the clusters are embedded. The statistical results are complemented with a deep, wide-field case

Charles H. Lineweaver, David Schwartzman

We review the thermal history of the Universe. We obtain a new estimate for the thermal history of the Earth over the past four billion years using a biological thermometer based on (1) a rough estimate of the absolute time calibration of the genetic distances in the 16S rRNA-based tree of terrestrial life and (2) the maximum growth temperatures of the extan

Maria Spiropulu

Selected topics showcasing the exploration for new physics using colliders; presented at TASI 2001.

Jungyeon Cho, A. Lazarian, Ethan T. Vishniac

We compare the properties of ordinary strong magnetohydrodynamic (MHD) turbulence in a strongly magnetized medium with the recently discovered viscosity-damped regime. We focus on energy spectra, anisotropy, and intermittency. Our most surprising conclusion is that in ordinary strong MHD turbulence the velocity and magnetic fields show different high-order s

Naoki Yoshida, Naoshi Sugiyama, Lars Hernquist

We critically examine how the evolution of the matter density field in cosmological simulations is affected by details of setting up initial conditions. We show that it is non-trivial to realise an initial distribution of matter in N-body/hydrodynamic simulations so that the baryon and dark matter density fluctuations and their velocities evolve consistently

Eric D. Carlson, William H. Hirsch, Benedikt Obermayer, Paul R. Anderson

The stress-energy tensor for the massless spin 1/2 field is numerically computed outside and on the event horizons of both charged and uncharged static non-rotating black holes, corresponding to the Schwarzschild, Reissner-Nordstrom and extreme Reissner-Nordström solutions of Einstein&#39;s equations. The field is assumed to be in a thermal state at the blac

Andrey V. Kravtsov, Oleg Y. Gnedin

We study the formation of globular clusters (GCs) in a Milky Way-size galaxy using a high-resolution cosmological simulation. The clusters in our model form in the dense cores of supergiant molecular clouds in the gaseous disks of high-redshift galaxies. The properties of clusters are estimated using a physically-motivated subgrid model of the isothermal clo

William H. Kinney, Edward W. Kolb, Alessandro Melchiorri, Antonio Riotto

We extract parameters relevant for distinguishing among single-field inflation models from the Wilkinson Microwave Anisotropy Probe (WMAP) data set, and from a combination of the WMAP data and seven other Cosmic Microwave Background (CMB) experiments. We use only CMB data and perform a likelihood analysis over a grid of models including the full error covari

George Svetlichny

We point out that the presence of energetic cosmic rays above the GZK cutoff may be explained by fundamental non-linearities in quantum mechanics at the Plank level.

Steven S. Gubser

Pair creation of strings in time-dependent backgrounds is studied from an effective field theory viewpoint, and some possible cosmological applications are discussed. Simple estimates suggest that excited strings may have played a significant role in preheating, if the string tension as measured in four-dimensional Einstein frame falls a couple of orders of

Sergei A. Klioner, Michael Peip

One of the most subtle points in the modern relativistic models for microarcsecond astrometrical observations is the treatment of the influence of translational motion of gravitating bodies on the light propagation. This paper describes numerical simulations of the light propagation in the gravitational field of moving gravitating bodies as well as summarize

Matsuo Sato, Asato Tsuchiya

We show that the effective actions of D-brane and M-brane are solutions to the Hamilton-Jacobi (H-J) equations in supergravities. This fact means that these effective actions are on-shell actions in supergravities. These solutions to the H-J equations reproduce the supergravity solutions that represent D-branes in a $B_2$ field, M2 branes and the M2-M5 bound

Henry E. Kandrup, Christos Siopis

This paper investigates chaos and chaotic phase mixing in triaxial Dehnen potentials which have been proposed to describe realistic ellipticals. Earlier work is extended by exploring the effects of (1) variable axis ratios, (2) `graininess&#39; associated with stars and bound substructures, idealised as friction and white noise, and (3) large-scale organised

D. Besson

Using 13.5 fb^{-1} of e^+e^- annihilation data collected with the CLEO-II detector, we have observed a new narrow resonance in the D_s^*π^0 final state, with a mass near 2.46 GeV/c^2. The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at 2.32 GeV/c^2, the D_{sJ}^*(2317)^+, that decays to D_sπ^0. Rec

Carla Biggio, Ferruccio Feruglio, Isabella Masina, Manuel Perez-Victoria

We discuss a toy model in six dimensions that predicts two fermion generations, natural mass hierarchy and intergenerational mixing. Matter is described by vector-like six dimensional fermions, one per each irreducible standard model representation. Two fermion generations arise from the compactification mechanism, through orbifold projection. They are local

Ruth A. Daly, S. G. Djorgovski

Determination of the expansion and acceleration history of the universe is one of the fundamental goals of cosmology. Detailed measurements of these rates as a function of redshift can provide new physical insights into the nature and evolution of the dark energy, which apparently dominates the global dynamics of the universe at the present epoch. We present

D. Fargion, P. G. De Sanctis Lucentini, M. De Santis. M. Grossi

We estimate the rate of observable Horizontal and Upward Tau Air-Showers (HORTAUs, UPTAUS) considering both the Earth opacity and the finite size of the terrestrial atmosphere. We calculate the effective target volumes and masses for Tau air-showers emerging from the Earth. The resulting model-independent masses for satellite experiments such as EUSO may enc

Ulf Lindstrom, Maxim Zabzine

We discuss the notion of tensionless limit in quantum bosonic string theory, especially in flat Minkowski space, noncompact group manifolds (e.g., SL(2,R)) and coset manifolds (e.g., AdS). We show that in curved space typically there exists a critical value of the tension which is related to the critical value of the level of the corresponding affine algebra

Athanasios Dedes, Giuseppe Degrassi, Pietro Slavich

We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary values of the bottom Yukawa coupling. We also compute the corrections to the minimization conditions of the effective potenti

Ashok Das, Xingxiang Zhou

We study the light-front Schwinger model at finite temperature following the recent proposal in \cite{alves}. We show that the calculations are carried out efficiently by working with the full propagator for the fermion, which also avoids subtleties that arise with light-front regularizations. We demonstrate this with the calculation of the zero temperature

Abhay Ashtekar, Alejandro Corichi, Daniel Sudarsky

The isolated horizon framework is extended to include non-minimally coupled scalar fields. As expected from the analysis based on Killing horizons, entropy is no longer given just by (a quarter of) the horizon area but also depends on the scalar field. In a subsequent paper these results will serve as a point of departure for a statistical mechanical derivat

Daniel J. H. Chung, Gary Shiu, Mark Trodden

The scalar spectral index n is an important parameter describing the nature of primordial density perturbations. Recent data, including that from the WMAP satellite, shows some evidence that the index runs (changes as a function of the scale k at which it is measured) from n>1 (blue) on long scales to n<1 (red) on short scales. We investigate the extent to w

I. Valtchanov, M. Pierre, J. Willis, S. Dos Santos

We present five newly found galaxy clusters at z>0.6 from the XMM Large-Scale Structure Survey (XMM-LSS). All five objects are extended X-ray sources in the XMM images. For three of them we have sufficient spectroscopically confirmed member galaxies that an estimate of the velocity dispersion is possible: XLSSC 001 at z=0.613 and σ_V=867^{+80}_{-60} km/s, XL

M. Pierre, I. Valtchanov, B. Altieri, S. Andreon

We have designed a medium deep large area X-ray survey with XMM - the XMM Large Scale Structure survey, XMM-LSS - with the scope of extending the cosmological tests attempted using ROSAT cluster samples to two redshift bins between 0<z<1 while maintaining the precision of earlier studies. Two main goals have constrained the survey design: the evolutionary st

Dirk H. Rischke

Our current knowledge of the quark-gluon plasma in thermodynamical equilibrium is reviewed. The phase diagram of strongly interacting matter is discussed, with emphasis on the quark-hadron phase transition and the color-superconducting phases of quark matter. Lattice QCD results on the order of the phase transition, the thermodynamical functions, the heavy q

Takashi Hamana, Issha Kayo, Naoki Yoshida, Yasushi Suto

We present a simple model that accurately describes various statistical properties of peculiar velocities of dark matter halos. We pay particular attention to the following two effects; first, the evolution of the halo peculiar velocity depends on the local matter density, instead of the global density. Second, dark matter halos are biased tracers of the und

A. Gerhold, A. Rebhan

Using generalized Nielsen identities a formal proof is given that the fermionic quasiparticle dispersion relations in a color superconductor are gauge independent. This turns out to involve gluonic tadpoles which are calculated to one-loop order in a two-flavor color superconductor. Regarding the appearance of gluon tadpoles, we argue that in QCD the color s

Cosma Rohilla Shalizi

It is increasingly common to encounter time-varying random fields on networks (metabolic networks, sensor arrays, distributed computing, etc.). This paper considers the problem of optimal, nonlinear prediction of these fields, showing from an information-theoretic perspective that it is formally identical to the problem of finding minimal local sufficient st

Eiichiro Komatsu, David N. Spergel, Benjamin D. Wandelt

We derive a fast way for measuring primordial non-Gaussianity in a nearly full-sky map of the cosmic microwave background. We find a cubic combination of sky maps combining bispectrum configurations to capture a quadratic term in primordial fluctuations. Our method takes only N^1.5 operations rather than N^2.5 of the bispectrum analysis (1000 times faster fo

Stephen Godfrey

The Babar and CLEO collaborations have recently observed states decaying to D_s^+π^0 and D_s^{*+}π^0 respectively and suggest the possible explanation that they are the missing P-wave c\bar{s} states with J^P=0^+ and 1^+. In this note we compare the properties of the D_{sJ}^*(2317)^+ and D_{sJ}(2463)^+ states to those expected of the c\bar{s} D_{s0}^* and D_

Brandon Carter, Nicolas Chamel

This is the first of a series of articles showing how 4 dimensionally covariant analytical procedures developed in the context of General Relativity can be usefully adapted for application in a purely Newtonian framework where they provide physical insights (e.g. concerning helicity currents) that are not so easy to obtain by the traditional approach based o

Philippe Gaucher

The branching (resp. merging) space functor of a flow is a left Quillen functor. The associated derived functor allows to define the branching (resp. merging) homology of a flow. It is then proved that this homology theory is a dihomotopy invariant and that higher dimensional branchings (resp. mergings) satisfy a long exact sequence.

Elliott H. Lieb, Robert Seiringer, Jakob Yngvason

Recent experimental and theoretical work has shown that there are conditions in which a trapped, low-density Bose gas behaves like the one-dimensional delta-function Bose gas solved years ago by Lieb and Liniger. This is an intrinsically quantum-mechanical phenomenon because it is not necessary to have a trap width that is the size of an atom -- as might hav

Issaku Kanamori, Noboru Kawamoto

We formulate Dirac-Kaehler fermion action by introducing a new Clifford product with noncommutative differential form on a lattice. Hermiticity of the Dirac-Kaehler action requires to choose the lattice structure having both orientabilities on a link. The Kogut-Susskind fermion and the staggered fermion actions are derived directly from the Dirac-Kaehler fer

Alejandro Frank, Piet van Isacker, Joaquin Gomez-Camacho

We carry out a simple analysis of (n+3)-dimensional gravity in the context of recent work on &#39;large&#39; supplementary dimensions and deduce a formula for the expected compactification radius for the n additional dimensions in the universe, as a function of the Planck and the electro-weak scales. We argue that the correspondingly modified gravitational f

L. Alvarez-Gaume, M. A. Vazquez-Mozo

In this paper we study general properties of noncommutative field theories obtained from the Seiberg-Witten limit of string theories in the presence of an external B-field. We analyze the extension of the Wightman axioms to this context and explore their consequences, in particular we present a proof of the CPT theorem for theories with space-space noncommut

G. V. Kraniotis, S. B. Whitehouse

The geodesic equations resulting from the Schwarzschild gravitational metric element are solved exactly including the contribution from the Cosmological constant. The exact solution is given by genus 2 Siegelsche modular forms. For zero cosmological constant the hyperelliptic curve degenerates into an elliptic curve and the resulting geodesic is solved by th

V. Cirigliano, E. Golowich, K. Maltman

We use the procedure of pinched-weight Finite Energy Sum Rules (pFESR) to determine the OPE coefficients a_6, ...,a_16 of the flavor ud V-A correlator in terms of existing hadronic tau decay data. We show by appropriate weight choices that the error on the dominant d=6 contribution, which is known to be related to the K -> Pi Pi matrix elements of the electr

Paola Gori-Giorgi, John P. Perdew

The negative correlation energy per particle of a uniform electron gas of density parameter $r_s$ and spin polarization $ζ$ is well known, but its spin resolution into up-down, up-up, and down-down contributions is not. Widely-used estimates are incorrect, and hamper the development of reliable density functionals and pair distribution functions. For the spi

Jerome Buzzi

We introduce subshifts of quasi-finite type as a generalization of the well-known subshifts of finite type. This generalization is much less rigid and therefore contains the symbolic dynamics of many non-uniform systems, e.g., piecewise monotonic maps of the interval with positive entropy. Yet many properties remain: existence of finitely many ergodic invari

Xin Zhou, Hu Chen, Mitsumasa Iwamoto

We have studied phase behavior of hard gaussian overlap molecules with small anisotropic parameter confined in two plane parallel structureless hard walls. Our investigation based on standard constant-NPT Monte Carlo molecular simulation led us to some interesting findings. For small anisotropic molecules the nematic phase is instable in bulk, while, if the

Balint Virag

We show that the past and future of half-plane Brownian motion at certain cutpoints are independent of each other after a conformal transformation. Like in Ito&#39;s excursion theory, the pieces between cutpoints form a Poisson process with respect to a local time. The size of the path as a function of this local time is a stable subordinator whose index is

H. H. Wen, H. P. Yang, S. L. Li, X. H. Zeng

By measuring the field and temperature dependence of magnetization on systematically doped $La_{2-x}Sr_xCuO_4$ thin films, the critical current density $j_c(0)$ and the collective pinning energy $U_p(0)$ are determined in single vortex creep regime. Together with the published data of superfluid density, condensation energy and anisotropy, for the first time

Ingela Roos, Klaus Molmer

The proposal for quantum computing with rare-earth-ion qubits in inorganic crystals makes use of the inhomogeneous broadening of optical transitions in the ions to associate individual qubits with ions responding to radiation in selected frequency channels. We show that a class of Gaussian composite pulses and complex sech pulses provide accurate qubit pi-ro

Sadataka Furui, Hideo Nakajima

The infrared features of Landau gauge QCD are studied by the lattice simulation of $β=6.0, 16^4, 24^4, 32^4$ and $β=6.4, 32^4, 48^4$. We adopt two definitions of the gauge field; 1) $U-$linear 2) $\log U$ and measured the gluon propagator and ghost propagator. Infrared singularity of the gluon propagator is less than that of tree level result but the gluon p

J. Suzuki

Recently, a set of thermodynamic Bethe ansatz equations is proposed by Dorey, Pocklington and Tateo for unitary minimal models perturbed by ϕ_{1,2} or ϕ_{2,1} operator. We examine their results in view of the lattice analogues, dilute A_L models at regime 1 and 2. Taking M_{5,6}+ϕ_{1,2} and M_{3,4}+ϕ_{2,1} as the simplest examples, we will explicitly show th

Rollin S. Armour

Requiring covariance of Maxwell's equations without {\it a priori} imposing charge invariance allows for both spin-1 and spin-1/2 transformations of the complete Maxwell field and current. The spin-1/2 case yields new transformation rules, with new invariants, for all traditional Maxwell field and source quantities. The accompanying spin-1/2 representations

Adrian P. Flitney, Derek Abbott

In game theory, a popular model of a struggle for survival among three competing agents is a truel, or three person generalization of a duel. Adopting the ideas recently developed in quantum game theory, we present a quantum scheme for the problems of duels and truels. In the classical case, the outcome is sensitive to the precise rules under which the truel

D. Iannuzzi, F. Capasso

A recent theoretical calculation shows that the Casimir force between two parallel plates can be repulsive for plates with nontrivial magnetic properties (O. Kenneth et al., Phys. Rev. Lett. 89, 033001 (2002)). According to the authors, the effect may be observed with known materials, such as ferrites and garnets, and it might be possible to engineer micro-

A. I. Magunov, I. Rotter, S. I. Strakhova

The line shape of resonances in the overlapping regime is studied by using the eigenvalues and eigenfunctions of the effective Hamiltonian of an open quantum system. A generalized expression $\tilde q_k(E)$ for the Fano parameter of the resonance state $k$ is derived that contains the interaction of the state $k$ with neighboured states $l\ne k$ via the cont

D. Mauro

In this paper we find a simple rule to reproduce the algebra of quantum observables using only the commutators and operators which appear in the Koopman-von Neumann (KvN) formulation of classical mechanics. The usual Hilbert space of quantum mechanics becomes embedded in the KvN Hilbert space: in particular it turns out to be the subspace on which the quantu

Boris Ivlev

The problem of inter-band tunneling in a semiconductor (Zener breakdown) in a nonstationary and homogeneous electric field is solved exactly. Using the exact analytical solution, the approximation based on classical trajectories is studied. A new mechanism of enhanced tunneling through static non-one-dimensional barriers is proposed in addition to well known

D. Ahn, H. J. Lee, S. W. Hwang, M. S. Kim

Quantum entanglements are of fundamental importance in quantum physics ranging from the quantum information processing to the physics of black hole. Here, we show that the quantum entanglement is not invariant in special relativity. This suggests that nearly all aspects of quantum information processing would be affected significantly when relativistic effec

John K. Stockton, JM Geremia, Andrew C. Doherty, Hideo Mabuchi

Analyzing the properties of entanglement in many-particle spin-1/2 systems is generally difficult because the system&#39;s Hilbert space grows exponentially with the number of constituent particles, $N$. Fortunately, it is still possible to investigate many-particle entanglement when the state of the system possesses sufficient symmetry. In this paper, we pr

E. R. Tracy, A. N. Kaufman

In more than one spatial dimension, resonant linear conversion from one wave type to another can have a more complex geometry than the familiar &#39;avoided crossing&#39; of one-dimensional problems. In previous work we have shown that helical ray shapes are generic in a mathematical sense. Here we briefly describe how the local field structure can be comput

Patrick C. Chaumet, Adel Rahmani, Manuel Nieto-Vesperinas

We propose a novel way to trap and manipulate nano-objects above a dielectric substrate using an apertureless near-field probe. A combination of evanescent illumination and light scattering at the probe apex is used to shape the optical field into a localized, three dimensional optical trap. We use the coupled-dipole method and the Maxwell stress tensor to p

P. C. Chaumet, M. Nieto-Vesperinas

Optical fields can induce forces between microscopic objects, thus giving rise to new structures of matter. We study theoretically these optical forces between two spheres, either isolated in water, or in presence of a flat dielectric surface. We observe different behavior in the binding force between particles at large and at small distances (in comparison

P. C. Chaumet, M. Nieto-Vesperinas

By using a method, previously established to calculate electromagnetic fields, we compute the force of light upon a metallic particle. This procedure is based on both Maxwell&#39;s Stress Tensor and the Couple Dipole Method. With these tools, we study the force when the particle is over a flat dielectric surface. The multiple interaction of light between the

P. C. Chaumet, M. Nieto-Vesperinas

We establish the time averaged total force on a subwavelength sized particle in a time harmonic varying field. Our analysis is not restrictive about the spatial dependence of the incident field. We discuss the addition of the radiative reaction term in the polarizability in order to correctly deal with the scattering force. As a consequence and illustration,

P. C. Chaumet, M. Nieto-Vesperinas

We present a theory to compute the force due to light upon a particle on a dielectric plane by the Coupled Dipole Method (CDM). We show that, with this procedure, two equivalent ways of analysis are possible, both based on Maxwell&#39;s stress tensor. The interest in using this method is that the nature and size or shape of the object, can be arbitrary. Even

Vladimir A. Baulin, Alexei R. Khokhlov

The isotropic-to-nematic transition in an athermal solution of long rigid rods subject to a gravitational (or centrifugal) field is theoretically considered in the Onsager approximation. The new feature emerging in the presence of gravity is a concentration gradient which coupled with the nematic ordering. For rodlike molecules this effect becomes noticeable

A. G. Barriuso, J. J. Monzon, L. L. Sanchez-Soto, J. F. Carinena

We reelaborate on the basic properties of lossless multilayers by using bilinear transformations. We study some interesting properties of the multilayer transfer function in the unit disk, showing that hyperbolic geometry turns out to be an essential tool for understanding multilayer action. We use a simple trace criterion to classify multilayers into three

Patrick C. Chaumet, Adel Rahmani, Manuel Nieto-Vesperinas

We present a detailed theoretical study of the recent proposal for selective nanomanipulation of nanometric particles above a substrate using near-field optical forces [Chaumet {\it et al.} Phys. Rev. Lett. {\bf 88}, 123601 (2002)]. Evanescent light scattering at the apex of an apertureless near-field probe is used to create an optical trap. The position of

J. L. Friar, G. L. Payne

Alternative definitions of the Born approximation and the distorted-wave Born approximation within the framework of the configuration-space Faddeev equations are explored. The most natural definition does not correspond to the Born approximation derived from the Schroedinger equation, even though the exact T-matrices for both formalisms are equivalent. The S

H. Witala, A. Nogga, H. Kamada, W. Glockle

The nd doublet and quartet scattering lengths have been calculated based on the modern NN and 3N interactions. We also studied the effect of the electromagnetic interactions in the form introduced in AV18. Switching them off for the various nuclear force models leads to shifts of up to +0.04 fm for doublet scattering length, which is significant for present

J. R. Castrejon Pita, A. A. Castrejon Pita, A. Sarmiento Galan, R. Castrejon Garcia

We analyze the geometrical structure of the astonishing Nasca geoglyphs in terms of their fractal dimension with the idea of dating these manifestations of human cultural engagements in relation to one another. Our findings suggest that the first delineated images consist of straight, parallel lines and that having sophisticated their abilities, Nasca artist

Eran Bouchbinder, H. George E. Hentschel, Itamar Procaccia

We address the theory of quasi-static crack propagation in a strip of glass that is pulled from a hot oven towards a cold bath. This problem had been carefully studied in a number of experiments that offer a wealth of data to challenge the theory. We improve upon previous theoretical treatments in a number of ways. First, we offer a technical improvement of

Sven Gnutzmann, Uzy Smilansky, Joachim Weber

We consider the real eigenfunctions of the Schrödinger operator on graphs, and count their nodal domains. The number of nodal domains fluctuates within an interval whose size equals the number of bonds $B$. For well connected graphs, with incommensurate bond lengths, the distribution of the number of nodal domains in the interval mentioned above approaches a

Victor S. L&#39;vov, Anna Pomyalov, Vasil Tiberkevich

We suggested a \emph{Multi-Zone Shell} (MZS) model for wall-bounded flows accounting for the space inhomogeneity in a &#34;piecewise approximation&#34;, in which cross-section area of the flow, $S$, is subdivided into &#34;$j$-zones&#34;. The area of the first zone, responsible for the core of the flow, $S_1\simeq S/2$, and areas of the next $j$-zones, $S_j$

R. Benzi, E. S. C. Ching, N. Horesh, I. Procaccia

A simple model of the effect of polymer concentration on the amount of drag reduction in turbulence is presented, simulated and analyzed. The qualitative phase diagram of drag coefficient vs. Reynolds number (Re) is recaptured in this model, including the theoretically elusive onset of drag reduction and the Maximum Drag Reduction (MDR) asymptote. The Re-dep

E. Alvarez-Lacalle, J. Casademunt, J. Ortin

This paper has been withdrawn.

G. Giachetta, L. Mangiarotti, G. Sardanashvily

Motivated by BRST theory, we study generalized symmetries and supersymmetries depending on derivatives of dynamic variables in a most general setting. We state the first variational formula and conservation laws for higher order Lagrangian systems on fiber bundles and graded manifolds under generalized symmetries and supersymmetries of any order. Cohomology

Krishnan Shankar, Ralf Spatzier, Burkhard Wilking

Let M be a complete Riemannian manifold whose sectional curvature is bounded above by 1. We say that M has positive spherical rank if along every geodesic one hits a conjugate point at t=π. The following theorem is then proved: If M is a complete, simply connected Riemannian manifold with upper curvature bound 1 and positive spherical rank, then M is isometr

L. Crane, D. N. Yetter

Using the theory of measurable categories developped by Yetter in work in preparation, we provide a notion of representations of 2-groups more well-suited to physically and geometrically interesting examples than that proposed in unpublished work of Barrett and Mackaay using 2-VECT of Kapranov and Voevodsky. Using this theory we sketch a 2-categorical approa

Pavel Etingof, Victor Kac

Recently, motivated by supersymmetric gauge theory, Cachazo, Douglas, Seiberg, and Witten proposed a conjecture about finite dimensional simple Lie algebras, and checked it in the classical cases. We prove the conjecture for type G_2, and also verify a consequence of the conjecture in the general case.

E. Andjel, P. A. Ferrari, A. Siqueira

We consider simple exclusion processes on Z for which the underlying random walk has a finite first moment and a non-zero mean and whose initial distributions are product measures with different densities to the left and to the right of the origin. We prove a strong law of large numbers for the number of particles present at time t in an interval growing lin

Daniel Dugger

This mostly expository paper records some basic facts about towers of homotopy fiber sequences. We give a proof that a pairing of towers induces a pairing of associated spectral sequences, for towers of spaces and towers of spectra.

Joerg Winkelmann

We construct certain non-degenerate maps and sets, mainly in the complex-analytic category. For example, we show that for every countable subset S in an irreducible complex space X there exists a holomorphic map from the unit disk to X such that S is contained in the image. Furthermore, given an irreducible complex space X, there is always an infinite subset

Konrad Schmuedgen, Elmar Wagner

For two covariant differential *-calculi, the twisted cyclic cocycle associated with the volume form is represented in terms of commutators [F,ρ(x)] for some self-adjoint operator F and some *-representation $ρ$ of the underlying *-algebra.

Nathanial P. Brown

A II_1 factor embeds into the ultraproduct of the hyperfinite II_1 factor if and only if it satisfies the W*-analogue of Lance&#39;s weak expectation property. This note gives a self contained proof of this fact.

Ronald Brown

This is a slightly edited version of the transparencies for a seminar at UCL, May 7, 2003. It is intended to give a quick view of background, ideas, and some calculations, in the applicatioon of some non commutative methods to algebraic topology.