January 2001 arXiv papers — page 24

J. Pumplin, D. Stump, R. Brock, D. Casey

We develop a general method to quantify the uncertainties of parton distribution functions and their physical predictions, with emphasis on incorporating all relevant experimental constraints. The method uses the Hessian formalism to study an effective chi-squared function that quantifies the fit between theory and experiment. Key ingredients are a recently

M. Fallot, J. A. Scarpaci, D. Lacroix, Ph. Chomaz

The 11Be break-up is calculated using a non perturbative time-dependent quantum calculation. The evolution of the neutron halo wave function shows an emission of neutron at large angles for grazing impact parameters and at forward angles for large impact parameters. The neutron angular distribution is deduced for the different targets and compared to experim

A. I. Karanikas, N. G. Stefanis

Demanding the analyticity of hadronic observables (calculated in terms of power series of the running coupling) as a {\it whole}, we show that they are free of the Landau singularity. Employing resummation and dispersion-relation techniques, we compute in a unifying way power corrections to two different hard-scattering functions in perturbative QCD: the ele

Joerg Schumacher, Bruno Eckhardt

The evolution of turbulent spots in a parallel shear flow is studied by means of full three-dimensional numerical simulations. The flow is bounded by free surfaces and driven by a volume force. Three regions in the spanwise spot cross-section can be identified: a turbulent interior, an interface layer with prominent streamwise streaks and vortices and a lami

C. M. Bender, D. C. Brody, B. K. Meister

It is possible to extract work from a quantum-mechanical system whose dynamics is governed by a time-dependent cyclic Hamiltonian. An energy bath is required to operate such a quantum engine in place of the heat bath used to run a conventional classical thermodynamic heat engine. The effect of the energy bath is to maintain the expectation value of the syste

P. P. Rajeev, S. Banerjee, A. S. Sandhu, L. C. Tribedi

The hard x-ray emission in the energy range of 30-300 keV from copper plasmas produced by 100 fs, 806 nm laser pulses at intensities in the range of 10$^{15}-10^{16}$ W cm$^{-2}$ is investigated. We demonstrate that surface roughness of the targets overrides the role of polarization state in the coupling of light to the plasma. We further show that surface r

Xiaoguang Wang

We study the entanglement in the quantum Heisenberg XY model in which the so-called W entangled states can be generated for 3 or 4 qubits. By the concept of concurrence, we study the entanglement in the time evolution of the XY model. We investigate the thermal entanglement in the two-qubit isotropic XY model with a magnetic field and in the anisotropic XY m

N. N. Achasov, V. V. Gubin

We study interference patterns in the $ϕ\to(γa_0+π^0ρ)\toγπη$ and $ϕ\to(γf_0+π^0ρ)\toγπ^0π^0$ reactions. Taking into account the interference, we fit the experimental data and show that the background reaction does not distort the $π^0η$ spectrum in the decay $ϕ\toγπη$ everywhere over the energy region and does not distort the $π^0π^0$ spectrum in the decay

Margaret Hawton, William E. Baylis

We extend a procedure for construction of the photon position operators with transverse eigenvectors and commuting components [Phys. Rev. A 59, 954 (1999)] to body rotations described by three Euler angles. The axial angle can be made a function of the two polar angles, and different choices of the functional dependence are analogous to different gauges of a

Gerd Klose, Greg Smith, Poul S. Jessen

We demonstrate a general method to measure the quantum state of an angular momentum of arbitrary magnitude. The (2F+1) x (2F+1) density matrix is completely determined from a set of Stern-Gerlach measurements with (4F+1) different orientations of the quantization axis. We implement the protocol for laser cooled Cesium atoms in the 6S_{1/2}(F=4) hyperfine gro

E. A. Tagirov

Ambiguities arising in different approaches (canonical, quasiclassical, path integration) to quantization are discussed by an example of the mechanics of a point-like particle in the Riemannian space (the geodesic dynamics). A way to select a single rule of quantization is proposed by requirement of a consistency of the quantum mechanics' following from

G. S. Agarwal, M. O. Scully, H. Walther

We propose a scheme for slowing down decay into a continuum. We make use of a sequence of ultrashort $2π$-pulses applied on an auxiliary transition of the system so that there is a destructive interference between the two transition amplitudes - one before the application of the pulse and the other after the application of the pulse. We give explicit results

Bogdan Mielnik

Contrary to the opinion of J. Polchinski [Phys.Rev.Lett. {\bf 66}, 397-400 (1991)], the phenomenon of superluminal messages in nonlinear versions of quantum mechanics is not a specific difficulty in a class of theories formulated by S. Weinberg [Ann.Phys. (N.Y.), {\bf 194}, 336-386 (1989)]. It appears in all schemes which try to enlarge the orthodox class of

Heng Fan, Xiang-Bin Wang, Keiji Matsumoto

Bužek and Hillery proposed a universal quantum-copying machine (UQCM) (i.e., transformation) to analyze the possibility of cloning arbitrary states. The UQCM copies quantum-mechanical states with the quality of its output does not depend on the input. We propose a slightly different transformation to analyze a restricted set of input states. We impose the co

Claus O. Wilke

We study the evolution of large but finite asexual populations evolving in fitness landscapes in which all mutations are either neutral or strongly deleterious. We demonstrate that despite the absence of higher fitness genotypes, adaptation takes place as regions with more advantageous distributions of neutral genotypes are discovered. Since these discoverie

V. I. Badin

To describe the generation of the electric field by a discontinuity of the Hall current, an equation of the third order is obtained using the electric charge conservation and Ohm laws. The solutions of this equation are used to model the electric impulses detected in experiments aimed to verify Alfven's hypothesis on the critical ionization velocity at c

Andreas Spille, Alexander Rauh, Heiko Buehring

We investigate the linear stability of plane Poiseuille flow in 2D under slip boundary conditions. The slip s is defined by the tangential velocity at the wall in units of the maximal flow velocity. As it turns out, the critical Reynolds number depends smoothly on s but increases quite rapidly.

Avraham Gal

Recent optical-potential studies of the phenomenology of kaonic atoms are reviewed. It is shown that the data can be fitted by a complex optical potential with either a relatively shallow attractive component (about -50 MeV at nuclear-matter density), as suggested by a self consistent application of chirally motivated coupled-channels models, or a relatively

Andrey A. Sukhorukov, Yuri S. Kivshar

We analyze the existence and stability of nonlinear localized waves described by the Kronig-Penney model with a nonlinear impurity. We study the properties of such waves in a homogeneous medium, and then analyze new effects introduced by periodicity of the medium parameters. In particular, we demonstrate the existence of a novel type of stable nonlinear band

E. Bogomolny, O. Giraud, C. Schmit

The 2-point correlation form factor, $K_2(τ)$, for small values of $τ$ is computed analytically for typical examples of pseudo-integrable systems. This is done by explicit calculation of periodic orbit contributions in the diagonal approximation. The following cases are considered: (i) plane billiards in the form of right triangles with one angle $π/n$ and (

A. G. Smirnov, M. A. Soloviev

The analytic aspects of the operator realization of Wick power series of infrared singular free fields are considered. Taking advantage of the holomorphy properties of the two-point correlation function and its Hilbert majorant in x-space, we solve in a general and model independent way the problem of finding the adequate test function space on which a given

A. G. Smirnov, M. A. Soloviev

The properties of infinite series in the Wick powers of a free field whose two-point correlation function has a singular infrared behavior and does not satisfy the positivity condition are investigated. If these series are defined on an appropriate functional domain, then the fields to which they converge satisfy all conditions of the pseudo-Wightman formali

Alexandr Borisov

In this paper we construct arithmetic analogs of the Riemann-Roch theorem and Serre's duality for line bundles. This improves on the works of Tate and van der Geer - Schoof. We define $H^0(L)$ and $H^1(L)$ as some convolution of measures structures. The $H^1$ is defined by a procedure very similar to the usual Cech cohomology. We get Serre's duality

Alexandru Nica, Dimitri Shlyakhtenko, Roland Speicher

We introduce the concept of ``R-cyclic family'' of matrices with entries in a non-commutative probability space; the definition consists in asking that only the ``cyclic'' non-crossing cumulants of the entries of the matrices are allowed to be non-zero. Let A_{1}, ..., A_{s} be an R-cyclic family of d \times d matrices over a non-commutative

U. Gritsch

In this paper we show the existence of non minimal critical points of the Yang-Mills functional over a certain family of 4-manifolds with generic SU(2)-invariant metrics using Morse and homotopy theoretic methods. These manifolds are acted on fixed point freely by the Lie group SU(2) with quotient a compact Riemann surface of even genus. We use a version of

Dmitry Orlov, Alexander Vishik, Vladimir Voevodsky

We construct a four-term exact sequence which provides information on the kernel and cokernel of the multiplication by a pure symbol in Milnor's K-theory mod 2 of fields of characteristic zero. As an application we establish, for fields of characteristics zero, the validity of three conjectures in the theory of quadratic forms - the Milnor conjecture on

Alexandre J. Chorin, Ole H. Hald, Raz Kupferman

Optimal prediction methods compensate for a lack of resolution in the numerical solution of complex problems through the use of prior statistical information. We know from previous work that in the presence of strong underresolution a good approximation needs a non-Markovian "memory", determined by an equation for the "orthogonal", i.e., unre

Grigori Litvinov, Victor Maslov

This paper is devoted to heuristic aspects of the so-called idempotent calculus. There is a correspondence between important, useful and interesting constructions and results over the field of real (or complex) numbers and similar constructions and results over idempotent semirings in the spirit of N. Bohr's correspondence principle in Quantum Mechanics.

Jan de Boer

In this lecture, we review the derivation of the holographic renormalization group given in hep-th/9912012. Some extra background material is included, and various applications are discussed.

Gordon Chalmers, Warren Siegel

A T-dualized selfdual inspired formulation of massive vector fields coupled to arbitrary matter is generated; subsequently its perturbative series modeling a spontaneously broken gauge theory is analyzed. The new Feynman rules and external line factors are chirally minimized in the sense that only one type of spin index occurs in the rules. Several processes

Yurii A. Sitenko

A massless spinor field is quantized in the background of a singular static magnetic vortex in 2+1-dimensional space-time. The method of self-adjoint extensions is employed to define the most general set of physically acceptable boundary conditions at the location of the vortex. Under these conditions, all effects of polarization of the massless fermionic va

Jan O. Conrad

We show how the level matching condition in six dimensional, abelian and supersymmetric orbifolds of the E_8 x E_8 heterotic string can be given equivalently in terms of fractional gauge and gravitational instanton numbers. This relation is used to restate the classification of the orbifolds in terms of flat bundles away from the orbifold singularities under

A. A. Deriglazov

We propose modified action which is equivalent to N=1 Green-Schwarz superstring and which allows one to realize the supplementation trick [26]. Fermionic first and second class constraints are covariantly separated, the first class constraints (1CC) turn out to be irreducible. We discuss also equations of motion in the covariant gauge for $κ$-symmetry. It is

Nadia Fettes, Ulf-G. Meißner

We consider pion-nucleon scattering in heavy-baryon chiral perturbation theory to third order. All electromagnetic corrections appearing to this order are included. We thus have a consistent description of strong and electromagnetic effects, which allows us to isolate the strong part of the interaction in an unambiguous way. We give pion-nucleon phase shifts

Ilya F. Ginzburg

Subjects of discussion Different scenarios Higgs window to a New Physics Anomalies in the interactions of gauge and Higgs bosons Some problems with t-quarks and MSSM. Some problems in QCD and hadron physics. By-product: Production of axions, etc. from region of conversion e --> gamma.

S. V. Talalov

The special case of 4D string-like theory proposed early is investigated. Regge trajectories in the developed model are non-linear for small masses and the values of spin and have the different asymptotical slopes $α_p$. The value $α_p$ just as the form of the trajectory depends from the quantum state of some ''internal'' {relativistic invari

A. J. Buchmann, E. M. Henley

We address the question of the intrinsic quadrupole moment Q_0 of the nucleon in various models. All models give a positive intrinsic quadrupole moment for the proton. This corresponds to a prolate deformation. We also calculate the intrinsic quadrupole moment of the Delta(1232). All our models lead to a negative intrinsic quadrupole moment of the Delta corr

Kiwoon Choi, Eung Jin Chun, Kyuwan Hwang

We point out that axino can be a natural candidate for sterile neutrino which would accommodate the LSND data with atmospheric and solar neutrino oscillations. It is shown that the so called 3+1 scheme can be easily realized when supersymmetry breaking is mediated by gauge interactions and also R-parity is properly broken. Among the currently possible soluti

Deog Ki Hong

I discuss some aspects of recent developments in color superconductivity in high density quark matter. I calculate the Cooper pair gap and the critical points at high density, where magnetic gluons are not screened. The ground state of high density QCD with three light flavors is shown to be a color-flavor locking state, which can be mapped into the low-dens

K. Kontros, A. Lengyel, Z. Tarics

We assume that the Pomeron is a sum of Regge multipoles, each corresponding to a finite gluon ladder. From a fit to the diffraction cone data of pp- and pbarp- scattering we found that the triple pole is significant for the rise of the ratio sigma_el/sigma_tot at high energies.

Tsao Chang, Guangjiong Ni

It has been known for many years that the measured mass-square of neutrino is probably negative. For solving this puzzle, we have further investigated the hypothesis that neutrinos are superluminal fermions. A new Dirac-type equation is proposed and a tachyonic quantum theory is briefly discussed. This equation is equivalent to two Weyl equations coupled tog

C. T. Sachrajda

I review the status of lattice simulations relevant for phenomenological studies of B-physics. Results for much-studied quantities such as f_B, B_B and form-factors for semileptonic decays are presented as well as those for quantities which have begun to be studied only recently (such as B-lifetimes). The improvement in the precision of the determinations of

Gaurav Khanna

In this paper we consider the collision of spinning holes using first order perturbation theory of black holes (Teukolsky formalism). With these results (along with ones, we published in the past) one can predict the properties of the gravitational waves radiated from the late stage inspiral of two spinning, equal mass black holes. Also we note that the ener

David J. Murray, Dale E. Parson

Correctness constraints provide a foundation for automated debugging within object-oriented systems. This paper discusses a new approach to incorporating correctness constraints into Java development environments. Our approach uses the Object Constraint Language ("OCL") as a specification language and the Java Debug Interface ("JDI") as a ver

Jorge J. Moré

We discuss the role of automatic differentiation tools in optimization software. We emphasize issues that are important to large-scale optimization and that have proved useful in the installation of nonlinear solvers in the NEOS Server. Our discussion centers on the computation of the gradient and Hessian matrix for partially separable functions and shows th

Jinwu Ye, A. Millis

By using mutual flux-attaching singular gauge transformations, we derive an effective action describing the zero temperature quantum phase transition from d-wave superconductor to underdoped regime. In this effective action, quantum fluctuation generated vortices couple to quasi-particles by a mutual statistical interaction with statistical angle θ, the vort

V. F. Gantmakher, G. A. Emelchenko, I. G. Naumenko, G. E. Tsydynzhapov

The temperature dependence of upper critical field B_c2 was determined from the shift of resistive transition ΔT(B) in nearly optimally doped Nd_{2-x}Ce_xCuO_{4-y} single crystals. Within the experimental accuracy, the weak-field data are described by power function B_c2 ~ (ΔT)^{3/2}. This result is compared with the data on heat capacity and analyzed in the

Gerrit E. W. Bauer, Yuli V. Nazarov, Arne Brataas

The recently developed semiclassical theory for magnetoelectronic circuits is applied to a transistor-like device consisting of a normal metal island and three magnetic terminals. The electric current between source and drain can be controlled by the magnetization of a ``base'' reservoir up to distances of the order of the spin-flip diffusion length.

C. Vanderzande, F. Daerden

We show that the dissipative Abelian sandpile on a graph L can be related to a random walk on a graph which consists of L extended with a trapping site. From this relation it can be shown, using exact results and a scaling assumption, that the dissipative sandpiles' correlation length exponent νalways equals 1/d_w, where d_w is the fractal dimension of t

V. Sandomirsky, A. V. Butenko, R. Levin, Y. Schlesinger

We describe here a novel approach to the subject of thermoelectric devices. The current best thermoelectrics are based on heavily doped semiconductors or semimetal alloys. We show that utilization of electric field effect or ferroelectric field effect, not only provides a new route to this problem, bypassing the drawbacks of conventional doping, but also off

Yoav Tsori, David Andelman

We investigate the ordered morphologies occurring in thin-films diblock copolymer. For temperatures above the order-disorder transition and for an arbitrary two-dimensional surface pattern, we use a Ginzburg-Landau expansion of the free energy to obtain a linear response description of the copolymer melt. The ordering in the directions perpendicular and para

Jan von Delft

We review recent experimental and theoretical work on superconductivity in ultrasmall metallic grains, i.e. grains sufficiently small that the conduction electron energy spectrum becomes discrete. The discrete excitation spectrum of an individual grain can be measured by the technique of single-electron tunneling spectroscopy, and reveals parity effects indi

A. P. Mills, A. P. Ramirez, X. P. A. Gao, L. N. Pfeiffer

We have measured the conductivity in a gated high-mobility GaAs two dimensional hole sample with densities in the range (7-17)x10^9 cm^-2 and at hole temperatures down to 5x10^-3 E_F. We measure the weak localization corrections to the conductivity g=G/(e^2/h) as a function of magnetic field (Delta g=0.019 +/- 0.006 at g=1.5 and T=9 mK) and temperature (d ln

J. Garrett Jernigan

The basic theory of torque free precession (TFP) of the outer crust of a neutron star (NS) as the signature of the approach to NS breakup is a viable explanation of the uniform properties of kHz Quasi-periodic Oscillations (QPO) observed in X-rays emitted by Low Mass X-ray Binary (LMXB) sources. The theory outlined in this paper relates the intrinsic propert

V. Kalogera, K. Belczynski

Double compact objects (neutron stars and black holes) found in binaries with small orbital separations are known to spiral in and are expected to coalesce eventually because of the emission of gravitational waves. Such inspiral and merger events are thought to be primary sources for ground based gravitational-wave interferometric detectors (such as LIGO). H

Richard B. Larson

This contribution summarizes briefly the main topics covered at this wide-ranging conference. Much of the evidence presented indicates that star formation occurs in discrete episodes or bursts that produce stellar groupings of all sizes, the fossil remnants of which make up the present stellar populations of galaxies.

Peter M. Woods, Chryssa Kouveliotou, Ersin Gogus, Mark H. Finger

We report the detection of large flux changes in the persistent X-ray flux of SGR 1900+14 during its burst active episode in 1998. Most notably, we find a factor ~700 increase in the non-burst X-ray flux following the August 27th flare, which decayed in time as a power-law. Our measurements indicate that the pulse fraction remains constant throughout this de

C. Weth

A simple model to explain the phase-dependence of the cyclotron absorption line observed in many X-Ray pulsars is presented. It includes several relativistic effects, namely gravitational redshift, gravitational light deflection, and - most important - doppler shift of the photon energy in the infalling plasma. It is shown that previous estimates of neutron

Christopher F. McKee

After reviewing recent work on the dynamics of young supernova remnants (YSNRs) and discussing how YSNRs can be used as physics laboratories, I discuss several challenges: Where are the very young SNRs in the Galaxy? Can very young SNRs produce gamma ray bursts? The Connections Challenge: Can one infer the nature of the supernova and its progenitor star from

Dong Lai

The secular instability and nonlinear evolution of the m=2 f-mode (bar-mode) driven by gravitational radiation reaction in a rapidly rotating, newly formed neutron star are reviewed. There are two types of rotating bars which generate quite different gravitational waveforms: those with large internal rotation relative to the bar figure (Dedekind-like bars) h

R. Capuzzo-Dolcetta, A. Vicari, P. Battinelli, G. Arrabito

We present some results of the application of our automatic technique for the identification of Young Star Groupings (YSGs) in spiral galaxies. In this report we discuss our new results for NGC 3377a and NGC 3507 together with previously published data of NGC 7217, NGC 1058 and UGC 12732. The aim of this ongoing research is to obtain a wide sample of homogen

David J. Thompson

High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The six or more pulsars seen by CGRO/EGRET show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and al

E. Le Floc'h, I. F. Mirabel, O. Laurent, V. Charmandaris

We report on Mid-Infrared (MIR) observations of the Seyfert 2 galaxy NGC 1068, obtained with ISOCAM in low-resolution spectro-imaging mode. The spatial resolution (around 5 arcsec) allows us to disentangle the circumnuclear starburst regions from the emission of the active galactic nucleus (AGN). The global spatial distribution of the Unidentified Infrared B

S. B. Kraemer, D. M. Crenshaw, J. B. Hutchings, I. M. George

We have examined the physical conditions in intrinsic UV-absorbing gas in the Seyfert galaxy NGC 4151, using echelle spectra obtained with the Space Telescope Imaging Spectrograph (STIS). We confirm the presence of the kinematic components detected in earlier GHRS observations as well as a new broad absorption feature at a radial velocity of -1680 km/s. The

T. Lu

There have been great and rapid progresses in the field of $γ$-ray bursts since BeppoSAX and other telescopes discovered their afterglows in 1997. In this talk, the main observational facts of $γ$-ray bursts and their afterglows, and the standard fireball shock model are reviewed briefly. And then, various post-standard effects, deviations from the standard

S. E. Shaw, A. J. Bird, A. J. Dean, N. Diallo

The BATSE mission aboard CGRO can be used to observe hard X-ray sources by using the Earth occultation method. This method relies on measuring a step in the count rate profile in each BATSE detector as a source rises above or sets below the Earth's limb. A major problem in determining the step sizes (and hence the flux) is in extracting the steps from th

O. Le Fèvre, G. Vettolani, D. Maccagni, D. Mancini

The aim of the VIRMOS VLT Deep Survey (VVDS) is to study of the evolution of galaxies, large scale structures and AGNs from a sample of more than 150,000 galaxies with measured redshifts in the range 0<z<5+. The VVDS will rely on the VIMOS and NIRMOS wide field multi-object spectrographs, which the VIRMOS consortium is delivering to ESO. Together, they offer

Q. Z. Liu, H. R Hang

We present a series of optical spectroscopic and near-infrared photometric observations of the Be star X Persei, from the beginning of the recent emission phase. Our data show that after the latest extended low state (ELS), both the equivalent width (EW) of the Hαemission line and the JHK luminosities gradually increased. The recent maximum HαEW and JHK magn

G. Israelian, R. Rebolo, R. Garcia Lopez, P. Bonifacio

Oxygen abundances in a sample of ultra-metal-poor subdwarfs have been derived from measurements of the oxygen triplet at 7771--5 A and OH lines in the near UV performed in high-resolution and high signal-to-noise spectra obtained with WHT/UES, KeckI/HIRES, and VLT/UVES. Our Fe abundances were derived in LTE and then corrected for NLTE effects following Theve

Werner Hofmann

Cherenkov telescopes image the Cherenkov emission from air showers. A priori, it is not obvious if the `best&#39; images are achieved by measuring Cherenkov photon angles, i.e. focusing the telescope at infinity, or by considering the air shower as an object to be imaged, in which case one might focus the telescope on the central region of the shower. The is

Jason X. Prochaska, Eric Gawiser, Arthur M. Wolfe

We present the first results from an ongoing survey to discover and measure the metallicity of z>3 damped Lya systems with the Echellette Spectrograph and Imager (ESI) on the Keck II telescope. Our motivation arises from a recent study on the damped Lya systems suggesting only mild evolution in the cosmic metallicity from z~2 to 4. The Echellette Spectrograp

Padeli Papadopoulos, Rob Ivison, Chris Carilli, Geraint Lewis

Molecular hydrogen is an important component of galaxies because it fuels star formation and accretion onto AGN, the two processes that generate the large infrared luminosities of gas-rich galaxies. Observations of spectral-line emission from the tracer molecule CO are used to probe the properties of this gas. But the lines that have been studied in the loca

Jan von Delft, D. C. Ralph

We review recent experimental and theoretical work on ultrasmall metallic grains, i.e. grains sufficiently small that the conduction electron energy spectrum becomes discrete. The discrete excitation spectrum of an individual grain can be measured by the technique of single-electron tunneling spectroscopy: the spectrum is extracted from the current-voltage c

Anna M. Delprato, Azadeh Samadani, A. Kudrolli, L. S. Tsimring

We report a novel morphological transition in a Bacillus subtilis colony initially growing under ambient conditions, after ultraviolet radiation exposure. The bacteria in the central regions of the colonies are observed to migrate towards the colony edge forming a ring during uniform spatial exposure. When the radiation is switched off, the colonies were obs

Christopher P. Herzog, Igor R. Klebanov

We derive type II supergravity solutions corresponding to space-filling regular and fractional Dp branes on (9-p)-dimensional conical transverse spaces. Fractional Dp-branes are wrapped D(p+2)-branes; therefore, our solutions exist only if the base of the cone has a non-vanishing Betti number b_2. We also consider 11-dimensional SUGRA solutions corresponding

Steven Corley, David A. Lowe

The brane world scenario advocated by Arkani-Hamed et al. transmutes the hierarchy problem into explaining why extra dimensions have sizes much larger than the fundamental scale. In this paper we discuss possible solutions to this problem by considering the compactified dimensions to be populated by a large number of branes in a crystal lattice. The experime

W. B. Hubbard, J. J. Fortney, J. I. Lunine, A. Burrows

We present a synthesis of physical effects influencing the observed lightcurve of an extrasolar giant planet (EGP) transiting its host star. The synthesis includes a treatment of Rayleigh scattering, cloud scattering, refraction, and molecular absorption of starlight in the EGP atmosphere. Of these effects, molecular absorption dominates in determining the t

Ali Mostafazadeh

We introduce the notion of the geometrically equivalent quantum systems (GEQS) as quantum systems that lead to the same geometric phases for a given complete set of initial state vectors. We give a characterization of the GEQS. These systems have a common dynamical invariant, and their Hamiltonians and evolution operators are related by symmetry transformati

Roger Ellman

The cosmic inflation hypothesis, its relation to fundamental theory on the beginning of the universe, and the light that both shed on how the various elements and their relative amounts came into existence. The fundamental factors controlling the origin of the universe ex nihilo are developed and from them the following alternative hypotheses are developed a

Andrzej Sitarz

New examples of noncommutative 4-spheres are introduced.

Peter A. Becker, Demosthenes Kazanas

The acceleration of relativistic particles due to repeated scattering across a shock wave remains the most attractive model for the production of energetic cosmic rays. This process has been analyzed extensively during the past two decades using the ``two-fluid&#39;&#39; model of diffusive shock acceleration. It is well known that 1, 2, or 3 distinct solutio

Daniel L. Blair, A. Kudrolli

We report the statistical properties of spherical steel particles rolling on an inclined surface being driven by an oscillating wall. Strong dissipation occurs due to collisions between the particles and rolling and can be tuned by changing the number density. The velocities of the particles are observed to be correlated over large distances comparable to th

E. O. Iltan

We calculate the electric dipole moment of electron using the experimental result of muon electric dipole moment and upper limit of the BR(μ--> eγ) in the framework of the general two Higgs doublet model. Our prediction is 10^{-32} e-cm, which lies in the experimental current limits. Further, we obtain constraints for the Yukawa couplings \barξ^{D}_{N,τe} an

Michael Meyer-Hermann, Andreas Deutsch, Michal Or-Guil

We introduce a new model for the dynamics of centroblasts and centrocytes in a germinal center. The model reduces the germinal center reaction to the elements considered as essential and embeds proliferation of centroblasts, point mutations of the corresponding antibody types represented in a shape space, differentiation to centrocytes, selection with respec

Alon Marcus

We consider N=1,2 superconformal mechanics in 0+1 dimensions and show that if the Hamiltonian is invertible the superconformal generators can be used to construct half of the super Virasoro algebra. The full algebra can be derived if the special conformal generator is also invertible. The generators are quantized and a general prescription is given for the c

Hwa-Kyun Park

We investigated the physical mechanism for the pattern transition from square lattice to stripes, which appears in vertically oscillating granular layers. We present a continuum model to show that the transition depends on the competition between inertial force and local saturation of transport. By introducing multiple free-flight times, this model further e

Hwa-Kyun Park

A variant of the complex Ginzburg-Landau equation is used to investigate the frequency locking phenomena in spatially extended systems. With appropriate parameter values, a variety of frequency-locked patterns including flats, $π$ fronts, labyrinths and $2π/3$ fronts emerge. We show that in spatially extended systems, frequency locking can be enhanced or sup

Phillip Kaye, Michele Mosca

If two parties, Alice and Bob, share some number, n, of partially entangled pairs of qubits, then it is possible for them to concentrate these pairs into some smaller number of maximally entangled states. We present a simplified version of the algorithm for such entanglement concentration, and we describe efficient networks for implementing these operations.

Qiong-gui Lin

We study the valence electron of an alkaline atom or a general charged particle with arbitrary spin and with magnetic moment moving in a rotating magnetic field. By using a time-dependent unitary transformation, the Schr\"odinger equation with the time-dependent Hamiltonian can be reduced to a Schr\"odinger-like equation with a time-independent effective Ham

T. N. Palmer

It is shown that in two-state quantum theory, a generic quantum state can be described by a non-computable real number. In terms of this, the criterion for measurement outcome is simply and deterministically defined. This demonstration is based on a construction of the Riemann sphere whose points represent, not complex numbers, but divergent sequences with b

M. B. Ruskai, E. Werner, S. Szarek

This paper has been superseded by quant-ph/0101003.

Z. Junhao, C. Xiang

Can we obtain the predictive value of GP-B experiment direct from the well known experimental results? This predictive value is more reliable then that deduced from special model of theory. In this paper, we calculate in this way. The result is same as that from special relativistic gravitational theory. So it is extremely likely that GP-B experiment will pr

Z. Junhao, C. Xiang

Whether the space-time is curved or not? The experimental criterions to judge this point are: (1) The results of three classical relativistic experiments in essence are favorable to the special relativistic gravitational theory (base in the flat space-time). However they are unfavorable to the general relativity. (2) In the Gravity Probe-B experiment: the gy

B. G. Sidharth

In this brief note, we argue that the elusive magnetic monopole arises due to the strong magnetic effects arising from the non commutative space time structure at small scales. This would also explain why the monopole has eluded detection even after seventy years.

Jens U. Noeckel, Guillaume Bourdon, Eric Le Ru, Richard Adams

We consider the wave and ray dynamics of the electromagnetic field in a parabolic dome microcavity. The structure of the fundamental s-wave involves a main lobe in which the electromagnetic field is confined around the focal point in an effective volume of the order of a cubic wavelength, while the modes with finite angular momentum have a structure that avo

I. Fachruddin, Ch. Elster, W. Gloeckle

A recently developed helicity basis for nucleon-nucleon (NN) scattering is applied to th e deuteron bound state. Here the total spin of the deuteron is treated in such a helicity representation. For the bound state, two sets of two coupled eigenvalue equations are developed, where the amplitudes depend on two and one variable, respectively. Numerical illustr

J. Main, G. Wunner

Periodic orbit quantization requires an analytic continuation of non-convergent semiclassical trace formulae. We propose two different methods for semiclassical quantization. The first method is based upon the harmonic inversion of semiclassical recurrence functions. A band-limited periodic orbit signal is obtained by analytical frequency windowing of the pe

Russell K. Standish

Numerous definitions for complexity have been proposed over the last half century, with little consensus achieved on how to use the term. A definition of complexity is supplied here that is closely related to the Kolmogorov Complexity and Shannon Entropy measures widely used as complexity measures, yet addresses a number of concerns raised against these meas

B. A. DiDonna, S. C. Venkataramani, T. A. Witten, E. M. Kramer

The crumpling of a thin sheet can be understood as the condensation of elastic energy into a network of ridges which meet in vertices. Elastic energy condensation should occur in response to compressive strain in elastic objects of any dimension greater than 1. We study elastic energy condensation numerically in 2-dimensional elastic sheets embedded in spati

David Eisenbud, Sorin Popescu, Sergey Yuzvinsky

We show that if X is the complement of a complex hyperplane arrangement, then the homology of X has linear free resolution as a module over the exterior algebra on the first cohomology of X. We study invariants of X that can be deduced from this resolution. A key ingredient is a result of Aramova, Avramov, and Herzog [2000] on resolutions of monomial ideals