August 2003 arXiv papers — page 20

Takao Suyama

We investigate a decay of a bulk tachyon with a Kaluza-Klein momentum in bosonic and Type 0 string theories compactified on S^1. Potential for the tachyon has a (local) minimum. A decay of the tachyon would lead the original theory to a strongly coupled theory. An endpoint of the decay would exist if the strong coupling limit exists and it is a stable theory

C. A. A. de Carvalho, R. M. Cavalcanti

We derive and analyze the perturbation series for the classical effective action in quantum statistical mechanics, treated as a toy model for the dimensionally reduced effective action in quantum field theory at finite temperature. The first few terms of the series are computed for the harmonic oscillator and the quartic potential.

O. J. P. Eboli, E. M. Gregores, J. K. Mizukoshi

The DELPHI Collaboration has recently reported the measurement of J/Psi production in photon-photon collisions at LEP II. These newly available data provide an additional proof of the importance of colored c bar{c} pairs for the production of charmonium because these data can only be explained by considering resolved photon processes. We show here that the i

W. Rodejohann

We point attention to the fact that in SO(10) models with non-canonical (type II) see-saw mechanism and exact b-tau unification the trace of the neutrino mass matrix is very small, in fact practically zero. This has the advantage of being a basis independent feature. Taking a vanishing trace as input, immediate phenomenological consequences for the values of

Masaaki Fujii, Masahiro Ibe

The minimal supersymmetric standard model (MSSM) has a truly supersymmetric way to explain both the baryon asymmetry and cold dark matter in the present Universe, that is, ``Affleck-Dine baryo/DM-genesis.'' The associated late-time decay of Q-balls directly connects the origins of the baryon asymmetry and dark matter, and also predicts a specific nat

F. Jegerlehner

Recent evaluations of the hadronic vacuum polarization contributions to the effective fine-structure constant alpha_{em}(M_Z) are summarized and commented. A new update based on corrected CMD-2 data is presented. My new estimates are Delta alpha_{had}^{(5)}(M_Z) = 0.027773 +/- 0.000354 (e^+e^- - data based) and Delta alpha_{had}^{(5)}(M_Z) = 0.027664 +/- 0.0

Jiri Chyla, Kamil Sedlak

Three widely used scenaria for defining cuts on transverse energies of jets in ep collisions are discussed. All of them are shown to suffer from the same sort of unphysical behaviour when the cut regions are subject to additional constraints. This feature is inherent in the very way dijet cross sections are defined and cannot be avoided. In particular, the s

S. V. Molodtsov, G. M. Zinovjev

An appraisal of average energy of Euclidean non-abelian point-like source in the instanton liquid is calculated. It behaves linearly increasing at large distances while unscreened. For the dipole in colour singlet state this energy increases linearly again with the separation increasing and its "tension" coefficient develops the magnitude pretty simi

Gregory Gabadadze

I give a brief and elementary introduction to braneworld models with large extra dimensions. Three conceptually distinct scenarios are outlined: (i) Large compact extra dimensions; (ii) Warped extra dimensions; (iii) Infinite-volume extra dimensions. As an example I discuss in detail an application of (iii) to late-time cosmology and the acceleration problem

Matthew Garbutt, Bruce H. J. McKellar

In this note we investigate the impact of new physics in the form of general four-fermion interactions on neutrino oscillation signals. We develop a field theoretic description of the overall oscillation process which includes the non-standard interactions during the neutrino production, propagation and detection stages. Insights gained during the developmen

Tetsutaro Higaki, Yoshiharu Kawamura, Tatsuo Kobayashi, Hiroaki Nakano

We study the $D$-term contribution for anomalous U(1) symmetries in type I string models and derive general formula for the $D$-term contribution, assuming that the dominant source of SUSY breaking is given by $F$-terms of the dilaton, (overall) moduli or twisted moduli fields. On the basis of the formula, we also point out that there are several different f

Jing Hua, Bo-Qiang Ma

The fragmentation functions of the pion with distinction between $D_{u}^{π^{+}}$, $D_{d}^{π^{+}}$, and $D_{s}^{π^{+}}$ are studied in the Field-Feynman recursive model, by taking into account the flavor structure in the excitation of quark-antiquark pairs by the initial quarks. The obtained analytical results are compatible with available empirical results.

Gerald Eigen

We summarize the latest BABAR results on B -> K(*) l+l- and B -> rho (omega) gamma

Satoshi Matsuda, Shigenori Seki

In order to resolve the hierarchy problem, large extra dimensions have been introduced, and it has been suggested that the size of extra dimensions is sub-millimeter. On the other hand, we assume in this paper that the cosmological constant comes from the Casimir energy of extra dimensions and estimate the size of extra dimensions in terms of the value of th

S. Asai, O. Jinnouchi, T. Kobayashi

The intrinsic decay rate of orthopositronium formed in ${\rm SiO_2}$ powder is measured using the direct $2\gamma$ correction method such that the time dependence of the pick-off annihilation rate is precisely determined. The decay rate of orthopositronium is found to be $7.0396\pm0.0012 (stat.)\pm0.0011 (sys.)\mu s^{-1}$, which is consistent with our previo

Ioannis Kouletsis, Petr Hajicek, Jiri Bicak

The model of cylindrical gravitational waves is employed to work out and check a recent proposal in Ref. [11] how a diffeomorphism-invariant Hamiltonian dynamics is to be constructed. The starting point is the action by Ashtekar and Pierri because it contains the boundary term that makes it differentiable for non-trivial variations at infinity. With the help

Daniel Vogt, Patricio S. Letelier

Using the well-known ``displace, cut and reflect'' method used to generate disks from given solutions of Einstein field equations, we construct static disks made of perfect fluid based on vacuum Schwarzschild's solution in isotropic coordinates. The same method is applied to different exactsolutions to the Einstein'sequations that represent s

Wlodzimierz Piechocki

We present quantization of particle dynamics on one-sheet hyperboloid embedded in three dimensional Minkowski space. Taking account of all global symmetries enables unique quantization. Making use of topology of canonical variables not only simplifies calculations but also gives proper framework for analysis.

Ali Mostafazadeh

For a FRW-spacetime coupled to an arbitrary real scalar field, we endow the solution space of the associated Wheeler-DeWitt equation with a Hilbert-space structure, construct the observables, and introduce the physical wave functions of the universe that admit a genuine probabilistic interpretation. We also discuss a proposal for the formulation of the dynam

Stephen Vavasis

We propose a sufficient condition for invertibility of a polynomial mapping function defined on a cube or simplex. This condition is applicable to finite element analysis using curved meshes. The sufficient condition is based on an analysis of the Bernstein-Bézier form of the columns of the derivative.

Valentin O. Turin, Alexander N. Korotkov

We have analyzed numerically the response and noise-limited charge sensitivity of a radio-frequency single-electron transistor (RF-SET) in a non-superconducting state using the orthodox theory. In particular, we have studied the performance dependence on the quality factor Q of the tank circuit for Q both below and above the value corresponding to the impeda

M. E. J. Newman, M. Girvan

We propose and study a set of algorithms for discovering community structure in networks -- natural divisions of network nodes into densely connected subgroups. Our algorithms all share two definitive features: first, they involve iterative removal of edges from the network to split it into communities, the edges removed being identified using one of a numbe

K. H. Ahn, Jian-Xin Zhu, Z. Nussinov, T. Lookman

We present an atomic scale theory of lattice distortions using strain related variables and their constraint equations. Our approach connects constrained atomic length scale variations to continuum elasticity and describes elasticity at all length scales. We apply the general approach to a two-dimensional square lattice with a monatomic basis, and find the a

J. M. Tranquada

Some recent evidence for the existence of dynamic, metallic stripes in the 214-family of cuprates is reviewed. The mechanism of stripe pinning is considered, and changes in the charge density within stripes between the pinned and dynamic phases is discussed. From a purely experimental perspective, dynamic charge stripes are fully compatible with nodal ``quas

E. M. L. Chung, G. J. McIntyre, D. McK. Paul, G. Balakrishnan

The possibilities of oxygen moment formation and canting in the quasi-1D cuprate Li2CuO2 are investigated using single crystal neutron diffraction at 2 K. The observed magnetic intensities could not be explained without the inclusion of a large ordered oxygen moment of 0.11(1) Bohr magnetons. Least-squares refinement of the magnetic structure of Li2CuO2 in c

Sumiyoshi Abe, Norikazu Suzuki

Discoveries of the scale-free and small-world features are reported on a network constructed from the seismic data. It is shown that the connectivity distribution decays as a power law, and the value of the degrees of separation, i.e., the characteristic path length or the diameter, between two earthquakes (as the vertices) chosen at random takes a small val

Pham Quoc Trieu, Hoang Nam Nhat

This works presents the theoretical study on several correlation integrals of the capacitance transients of the deep levels. The deconvolution of the transient signals was the major subject of the number of methods referred to under the common name as the Deep Level Transient Spectroscopy methods. In general the separation of the overlapping exponential deca

D. D. Sarma, S. R. Krishnakumar, E. Weschke, C. Schussler-Langeheine

We have performed a detailed high-resolution electron spectroscopic investigation of NiS$_2$ and related Se-substituted compounds NiS$_{2-x}$Se$_x$, which are known to be gapped insulators in the bulk at all temperatures. A large spectral weight at the Fermi energy of the room temperature spectrum, in conjunction with the extreme surface sensitivity of the e

Victor Galitski, V. A. Khodel

We study the renormalization of the Fermi-liquid parameters in the vicinity of a density wave quantum phase transition, which should occur in MOSFET systems at low densities. First, using a perturbative RPA treatment of fluctuations, we calculate the electronic self-energy and show that the effective mass diverges at the density wave transition point. Second

R. Zitzler, N. Tong, Th. Pruschke, R. Bulla

The Mott-Hubbard metal-insulator transition in the paramagnetic phase of the one-band Hubbard model has long been used to describe similar features in real materials like V$_2$O$_3$. Here we show that this transition is hidden inside a rather robust antiferromagnetic insulator even in the presence of comparatively strong magnetic frustration. This result rai

Y. D. Park, J. D. Lim, K. S. Suh, S. B. Shim

Highly p-type GaAs:C was ion-implanted with Mn at differing doses to produce Mn concentrations in the 1 - 5 at.% range. In comparison to LT-GaAs and n+GaAs:Si samples implanted under the same conditions, transport and magnetic properties show marked differences. Transport measurements show anomalies, consistent with observed magnetic properties and with epi-

J. -Y. Lin, H. D. Yang

The newly discovered superconductivity in MgCNi3, though with Tc<8 K lower than that of the celebrated MgB2, is probably even more interesting in its many puzzling physical properties. MgCNi3 has been theoretically speculated to be unstable towards ferromagnetism. However, there are numerous evidences from the specific heat C(T), Tunneling spectroscopy and N

H. D. Yang, S. Mollah, W. L. Huang, P. L. Ho

The effect of hydrostatic pressure (P) up to 17 kbar on the superconducting transition temperature (Tc) of the newly discovered intermetallic non-oxide perovskite superconductor MgCxNi3 has been reported. The TC is found to increase with increasing P at a rate of dTc/dP ~ 0.0134 to 0.0155 K/kbar depending on the value of carbon content x. The absolute value

Y. Aoki, A. Tsuchiya, T. Kanayama, S. R. Saha

We report on muon spin relaxation measurements of the 4f^2-based heavy-fermion superconductor filled-skutterudite PrOs4Sb12. The results reveal the spontaneous appearance of static internal magnetic fields below the superconducting transition temperature, providing unambiguous evidence for the breaking of time-reversal symmetry in the superconducting state.

Luis Lafuente, Jose A. Cuesta

To speak about fundamental measure theory obliges to mention dimensional crossover. This feature, inherent to the systems themselves, was incorporated in the theory almost from the beginning. Although at first it was thought to be a consistency check for the theory, it rapidly became its fundamental pillar, thus becoming the only density functional theory wh

E. Taylor, E. Zaremba

We study the Bogoliubov excitations of a Bose-condensed gas in an optical lattice. Of primary interest is the long wavelength phonon dispersion for both current-free and current-carrying condensates. We obtain the dispersion relation by carrying out a systematic expansion of the Bogoliubov equations in powers of the phonon wave vector. Our result for the cur

I. B. Bischofs, U. S. Schwarz

Adhering cells actively probe the mechanical properties of their environment and use the resulting information to position and orient themselves. We show that a large body of experimental observations can be consistently explained from one unifying principle, namely that cells strengthen contacts and cytoskeleton in the direction of large effective stiffness

J. Menche, J. R. L. de Almeida

In this work the properties of multi choice minority games are studied by means of extensive computational simulations. We have considered several ways of rewarding the strategies of the players and compared the resulting behaviours of the ensemble. It is shown that introducing a reward for the second place can improve the overall performance significantly.

Joshua Schrier, K. Birgitta Whaley

Recent experiments on Mn-doped ZnS nanocrystals have shown unusual magnetization properties. We describe a nearest-neighbor Heisenberg exchange model for calculating the magnetization ratios of these antiferromagnetically doped crystals, in which the dopant atoms are distributed inhomogeneously within the nanocrystal. This simple inhomogeneous doping model i

S. I. Simdyankin, Normand Mousseau

We identify the dynamical heterogeneities as an essential prerequisite for stretched exponential relaxation in dynamically frustrated systems. This heterogeneity takes the form of ordered domains of finite but diverging lifetime for particles in atomic or molecular systems, or spin states in magnetic materials. At the onset of the dynamical heterogeneity, th

Christopher J. Conselice, Scott C. Chapman, Rogier A. Windhorst

Sub-mm detected galaxies located at redshifts $z > 1$ host a major fraction of the bolometric luminosity at high redshifts due to thermal emission from heated dust grains, yet the nature of these objects remains a mystery. The major problem in understanding their origin is whether the dust heating mechanism is predominantly caused by star formation or active

Michael R. Santos

Lyman-alpha emission from high-redshift galaxies may be a powerful probe of the ionization history of the IGM at z>6: the observed Lyman-alpha emission line is sensitive to the neutral fraction of IGM hydrogen in the range 0.1-1. We present calculations of observed Lyman-alpha emission lines from z>6 galaxies, illustrating the effect of varying the many free

Sidney van den Bergh

Some factors connecting the evolutionary histories of galaxies with the characteristics of their cluster systems are reviewed. Unanswered questions include: How is one to understand the observation that some globular cluster systems have disk kinematics whereas others do not? Why do some galaxies have cluster systems with unimodal metallicity distributions,

Mark Lacy, Robert H. Becker, Lisa J. Storrie-Lombardi, Michael D. Gregg

We have identified galaxies near two quasars which are at the redshift of damped Lyman-alpha (DLA) systems in the UV spectra of the quasars. Both galaxies are actively forming stars. One galaxy has a luminosity close to the break in the local galaxy luminosity function, L*, the other is significantly fainter than L* and appears to be interacting with a nearb

Chris J. Willott, Steve Rawlings, Jennifer A. Grimes

We have carried out the first systematic survey of the sub-millimeter properties of broad absorption line (BAL) quasars. 30 BAL quasars drawn from a homogeneously selected sample from the Sloan Digital Sky Survey at redshifts 2<z<2.6 were observed with the SCUBA array at the JCMT to a typical rms sensitivity of 2.5 mJy. Eight quasars were detected at > 2 sig

Hsiao-Wen Chen, Kenneth M. Lanzetta

We study the nature of damped Lya absorption (DLA) systems at z<=1 using a sample of 11 DLA galaxies, for which accurate redshift measurements are available. We demonstrate that the precision of photometric redshifts is sufficient for identifying DLA galaxies, because DLAs are rare and their intrinsically high column density implies a small impact parameter

D. A. Frail, B. D. Metzger, E. Berger, S. R. Kulkarni

We present a sample of radio afterglow light curves with measured decay slopes which show evidence for a flattening at late times compared to optical and X-ray decay indices. The simplest origin for this behavior is that the change in slope is due to a jet-like outflow making a transition to sub-relativistic expansion. This can explain the late-time radio li

K. Sheth, D. A. Frail, S. White, M. Das

We present the results of a dedicated campaign on the afterglow of GRB 030329 with the millimeter interferometers of the Owens Valley Radio Observatory (OVRO), the Berkeley-Illinois-Maryland Association (BIMA), and with the MAMBO-2 bolometer array on the IRAM 30-m telescope. These observations allow us to trace the full evolution of the afterglow of GRB 0303

E. Berger, S. R. Kulkarni, G. Pooley, D. A. Frail

Past studies suggest that long-duration gamma-ray bursts (GRBs) have a standard energy of E_gamma ~ 10^51 erg in ultra-relativistic ejecta when corrected for asymmetry (&#34;jets&#34;). However, recently a group of sub-energetic bursts, including the peculiar GRB 980425 associated with SN 1998bw (E_gamma ~ 10^48 erg), has been identified. Here we report radi

Adam G. Riess, Louis-Gregory Strolger, John Tonry, Zlatan Tsvetanov

We present discoveries of SNe Ia at z > 1 and the photometric diagnostic used to discriminate them from other types of SNe detected during the GOODS Hubble Space Telescope Treasury program with the Advanced Camera for Surveys (ACS). Photometric redshift measurements of the hosts combined with deep f606w, f775w, and f850lp imaging discriminates hydrogen-rich

J. Madej, M. Pietrachowicz, P. C. Joss, A. Majczyna

We explore photometric properties of hypothetical iron core white dwarfs and compute their expected colors in UBVRI Johnson broadband system. Atmospheres of iron core WDs in this paper consist of pure iron covered by a pure hydrogen layer of an arbitrary column mass. LTE model atmospheres and theoretical spectra are calculated on the basis of Los Alamos TOPS

Mikel Susperregi

A cosmological scenario is proposed where the dark matter (DM) and dark energy (DE) of the universe are two simultaneous manifestations of an inhomogenous dilaton. The equation of state of the field is scale-dependent and pressureless at galactic and larger scales and it has negative pressure as a DE at very large scales. The dilaton drives an inflationary p

R. O. Gray, C. J. Corbally, R. F. Garrison, M. T. McFadden

We have embarked on a project, under the aegis of the Nearby Stars (NStars)/ Space Interferometry Mission Preparatory Science Program to obtain spectra, spectral types, and, where feasible, basic physical parameters for the 3600 dwarf and giant stars earlier than M0 within 40 parsecs of the sun. In this paper we report on the results of this project for the

C. L. Barbosa, A. Damineli, R. D. Blum, P. S. Conti

We present a mid-infrared study of NGC 3576. The high-resolution images were taken at the Gemini South Observatory through narrow and broad band filters centered between 7.9 micron and 18 micron. The nearly diffraction limited images show IRS 1 resolved into 4 sources for the first time in the 10 micron band. The positions of the sources are coincident with

Frederick K. Lamb, M. Coleman Miller

KHz QPOs have now been detected in more than twenty accreting neutron stars in low-mass binary systems. Two kHz QPOs are usually detected in each star. Burst oscillations and two kHz QPOs have recently been detected in the 401 Hz accretion-powered X-ray pulsar SAX J1808.4-3658. In this star the frequency of the burst oscillation is approximately equal to the

Laura Pentericci, Hans W. Rix, Francisco Prada, Xiaohui Fan

We present J-H-K&#39; photometry for a sample of 45 high redshift quasars found by the Sloan Digital Sky Survey. The sample was originally selected on the basis of optical colors and spans a redshift range from 3.6 to 5.03. Our photometry reflects the rest-frame SED longward of Ly alpha for all redshifts. The results show that the near-IR colors of high reds

K. Jahnke, L. Wisotzki

We report on the analysis of B band imaging data of 57 low-redshift QSOs and Seyfert 1 galaxies selected from the Hamburg/ESO-Survey, for which host galaxy dependent selection biases are greatly reduced compared to other optical surveys. Only one object in the sample is known to be radio-loud. We adopted a procedure to remove the AGN contribution by subtract

P. O. Petrucci, C. Cabanac, G. Henri, L. Maraschi

Mkn 841 has been observed simultaneously by XMM and BeppoSAX in January 2001. Due to operational contingency, the 30ks XMM observation was split into two parts, separated by about 15 hours. We first report the presence of a narrow iron line which appears to be rapidly variable between the two pointings, requiring a non-standard interpretation. We then focus

V. B. Il&#39;in, N. V. Voshchinnikov, V. A. Babenko, S. A. Beletsky

We present a database containing information on different aspects of calculation and usage of the optical properties of small non-spherical particles -- cosmic dust analogues. The main parts of the DOP are a review of available methods of the light scattering theory, collection of light scattering codes, special computational tools, a graphic library of the

P. O. Petrucci, M. Dadina

We present preliminary results of the spectral analysis of a large sample of Seyfert galaxies observed by BeppoSAX. The only selection criterium was a sufficiently large S/N ratio (>10) in the PDS band (12-200 keV) to allow good detection up to the highest energy. The resulting sample is composed of 28 objects (17 Seyfert 1, 11 Seyfert 2) and 50 observations

S. Mereghetti, D. Gotz, J. Borkowski, R. Walter

We describe the INTEGRAL Burst Alert System (IBAS): the automatic software for the rapid distribution of the coordinates of the Gamma-Ray Bursts detected by INTEGRAL. IBAS is implemented as a ground based system, working on the near-real time telemetry stream. During the first six months of operations, six GRB have been detected in the field of view of the I

James Binney

Using only the assumption that all interactions between particles in an accretion flow are electromagnetically mediated, it is shown that the time to establish equipartition between ions and electrons is shorter than the characteristic accretion time. Consequently, two-temperature fits to the spectra of accreting objects are unphysical, and models in which s

P. S. Barklem, A. K. Belyaev, M. Asplund

Rate coefficients for inelastic collisions between Li and H atoms covering all transitions between the asymptotic states Li(2s,2p,3s,3p,3d,4s,4p,4d,4f)+H(1s) and Li^+ +H^- are presented for the temperature range 2000-8000 K based on recent cross-section calculations. The data are of sufficient completeness for non-LTE modelling of the Li I 670.8 nm and 610.4

Daisuke Kawata, Brad K. Gibson

We study the chemodynamical evolution of elliptical galaxies and their X-ray and optical properties using high-resolution cosmological simulations. Our Tree N-body/SPH code includes a self-consistent treatment of radiative cooling, star formation, supernovae feedback, and chemical enrichment. We present a series of LCDM cosmological simulations which trace t

Yu-Qing Lou

We construct both aligned and unaligned (logarithmic spiral) stationary configurations of nonaxisymmetric magnetohydrodynamic (MHD) disks from either a full or a partial razor-thin power-law axisymmetric magnetized singular isothermal disk (MSID) that is embedded with a coplanar azimuthal magnetic field $B_θ$ of a non-force-free radial scaling $r^{-1/2}$ and

James M. Cline

This paper has been withdrawn by the author. It was argued that increasing F&#39; would reduce the strength of the scalar coupling to matter. This argument failed to realize that the gravitational coupling to matter is controlled by the same power of F&#39;, hence the scalar always couples with the same strength as gravity.

Neil Trentham

In this review I will describe a number of recent advances in extragalactic astronomy. First of all I will describe our current best estimates of the star formation history of the Universe. Then I will describe measurements of local galaxies and their stellar populations, concentrating on measurements of the luminosity functions and stellar population compos

Amir Hajian, Tarun Souradeep

The breakdown of statistical homogeneity and isotropy of cosmic perturbations is a generic feature of ultra large scale structure of the cosmos, in particular, of non trivial cosmic topology. The statistical isotropy (SI) of the Cosmic Microwave Background temperature fluctuations (CMB anisotropy) is sensitive to this breakdown on largest scales comparable t

R. Ouyed, O. Elgaroy, H. Dahle, P. Keranen

We present a new model for soft gamma-ray repeaters based on a quark star born with temperatures above the critical value (T_c) for the onset of the colour-flavor locked superconductivity. The quark star then quickly cools below T_c, expelling a fraction of the surface magnetic field via the Meissner effect. We show that if a small fraction (\leq 10%) of the

Y. Bergner, Luis M. A. Bettencourt

We generalize the standard computation of homogeneous nucleation theory at zero temperature to a scenario in which the bubble shape is determined self-consistently with its quantum fluctuations. Studying two scalar models in 1+1 dimensions, we find the self-consistent bounce by employing a two-particle irreducible (2PI) effective action in imaginary time at

Xiang-Bin Wang

We propose a prepare-and-measure scheme for quantum key distribution with 2-bit quantum codes. The protocol is unconditionally secure under whatever type of intercept-and-resend attack. Given the symmetric and independent errors to the transmitted qubits, our scheme can tolerate a bit error rate up to 26% in 4-state protocol and 30% in 6-state protocol, resp

A. Pasquali, J. S. Gallagher, R. de Grijs

We have made use of archival HST BVIJH photometry to constrain the nature of the three discrete sources, A1, A2 and B1, identified in the double nucleus of NGC 6240. STARBURST99 models have been fitted to the observed colours, under the assumption, first, that these sources can be treated as star clusters (i.e. single, instantaneous episodes of star formatio

Gyula Bene, Viktor Czinner, Matyas Vasuth

We point out that, due to the nonlinearity of the Einstein equations, a homogeneous approximation in cosmology leads to the appearance of an additional term in the Friedmann equation. This new term is associated with the spatial inhomogeneities of the metric and can be expressed in terms of density fluctuations. Although it is not constant, it decays much sl

Alberto Accardi, Miklos Gyulassy

Multiple initial state parton interactions in p(d)+Au collisions are calculated in a Glauber-Eikonal formalism. The convolution of perturbative QCD parton-nucleon cross sections predicts naturally the competing pattern of low-pT suppression due geometrical shadowing, and a moderate-pT Cronin enhancement of hadron spectra. The formal equivalence to recent cla

Edo Waks, Eleni Diamanti, Yoshihisa Yamamoto

The Visible Light Photon Counter (VLPC) has the capability to discriminate photon number states, in contrast to conventional photon counters which can only detect the presence or absence of photons. We use this capability, along with the process of parametric down-conversion, to generate photon number states. We experimentally demonstrate generation of state

Edo Waks, Kyo Inoue, Eleni Diamanti, Yoshihisa Yamamoto

The Visible Light Photon Counter (VLPC) features high quantum efficiency and low pulse height dispersion. These properties make it ideal for efficient photon number state detection. The ability to perform efficient photon number state detection is important in many quantum information processing applications, including recent proposals for performing quantum

G. Ka&#34;lbermann

We investigate numerically the quantum collision between a stable Helium nanodrop and an infinitely hard wall in one dimension. The scattering outcome is compared to the same event omitting the quantum pressure. Only the quantum process reflects the effect of diffraction of wave packets in space and time.

S. Setayeshgar, C. W. Gear, H. G. Othmer, I. G. Kevrekidis

We have developed and implemented a numerical evolution scheme for a class of stochastic problems in which the temporal evolution occurs on widely-separated time scales, and for which the slow evolution can be described in terms of a small number of moments of an underlying probability distribution. We demonstrate this method via a numerical simulation of ch

Dzmitry M. Shyroki

Intermodal interactions displayed through the phenomena of mode coupling and conversion in optical systems are treated by means of the Lindstedt-Poincare perturbation method of strained parameters more widely known in classical quantum mechanics and quantum chemistry as the stationary perturbation technique. The focus here is on the mode conversion at the po

A. Ya. Maltsev, S. P. Novikov

This is a survey article dedicated to the study of topological quantities in theory of normal metals discovered in the works of the authors during the last years. Our results are based on the theory of dynamical systems on Fermi surfaces. The physical foundations of this theory (the so-called &#34;Geometric Strong Magnetic Field Limit&#34;) were found by the

Dimitri Shlyakhtenko

We give an general estimate for the non-microstates free entropy dimension $δ^{*}(X_{1},..., X_{n})$. If $X_{1},..., X_{n}$ generate a diffuse von Neumann algebra, we prove that $δ^{*}(X_{1},..., X_{n})\geq 1$. In the case that $X_{1},..., X_{n}$ are $q$-semicircular variables as introduced by Bozejko and Speicher and $q^{2}n<1$, we show that $δ^{*}(X_{1},..

Itai Benjamini, Chris Hoffman

$ω$-periodic graphs are introduced and studied. These are graphs which arise as the limits of periodic extensions of the nearest neighbor graph on the integers. We observe that all bounded degree $ω$-periodic graphs are ameanable. We also provide examples of $ω$-periodic graphs which have exponential volume growth, non-linear polynomial volume growth and int

Aicke Hinrichs, Jörg Wenzel

We consider the question whether the trigonometric system can be equivalent to some rearrangement of the Walsh system in L_p for some p<>2. We show that this question is closely related to a combinatorial problem. This enables us to prove non-equivalence for a number of rearrangements. Previously this was known for the Walsh-Paley order only.

Paul S. Muhly, Baruch Solel

Given a von Neumann algebra $M$ and a $W^{\ast}$-correspondence $E$ over $M$, we construct an algebra $H^{\infty}(E)$ that we call the Hardy algebra of $E$. When $M=\mathbb{C}=E$, then $H^{\infty}(E)$ is the classical Hardy space $H^{\infty}(\mathbb{T})$ of bounded analytic functions on the unit disc. We show that given any faithful normal representation $σ$

Lawrence Breen, William Messing

We define in a global manner the notion of a connective structure for a gerbe on a space X. When the gerbe is endowed with trivializing data with respect to an open cover of X, we describe this connective structure in two separate ways, which extend from abelian to general gerbes the corresponding descriptions due to J.- L. Brylinski and N. Hitchin. We give

S. Jalalzadeh, F. Ahmadi, H. R. Sepangi

We study the classical and quantum cosmology of a $(4+d)$-dimensional spacetime minimally coupled to a scalar field and present exact solutions for the resulting field equations for the case where the universe is spatially flat. These solutions exhibit signature transition from a Euclidean to a Lorentzian domain and lead to stabilization of the internal spac

A. V. Afanasev, I. Akushevich, A. Ilyichev, B. Niczyporuk

We discuss the theoretical approach and practical algorithms for simulation of radiative events in elastic ep-scattering. A new Monte Carlo generator for real photon emission events in the process of elastic electron-proton scattering is presented. We perform a few consistency checks and present numerical results.

Marek Karliner, Harry J. Lipkin

Motivated by the recent discovery of the exotic S=+1 narrow baryon resonance Theta^+ at 1540 MeV, with quark content {uudd sbar}, we conjecture the existence of its anti-charmed analogue Theta_c, with quark content {uudd cbar}, and compute its likely properties. We rely on the recently constructed model of a novel kind of a pentaquark with an unusual color s

M. N. Chernodub, Katsuya Ishiguro, Tsuneo Suzuki

We study the action of the lattice monopoles in quenched SU(2) QCD in the Maximal Abelian projection. We relate the lattice action of the monopole currents to the monopole degrees of freedom of the continuum dual superconductor model and obtain the value of the monopole condensate.

O. Jinnouchi, S. Asai, T. Kobayashi

The intrinsic decay rate of orthopositronium formed in ${\rm SiO_2}$ powder is measured using the direct $2γ$ correction method such that the time dependence of the pick-off annihilation rate is precisely determined using high energy-resolution germanium detectors. As a systematic test, two different types of ${\rm SiO_2}$ powder are used with consistent fin

The Belle Collaboration, K. Abe

We report the first observation of a narrow charmmonium state produced in the exclusive decay process B+->K+ pi+pi- J/psi. This state, which decays into pi+pi-J/psi, has a mass of 3871.8+-0.7(stat)+-0.4(syst) MeV, which is very near the M_D + M_D* mass threshold. The results are based on an analysis of 152M BBbar events collected at the Upsilon(4S) resonance

Samad Khakshournia, Reza Mansouri

We consider a spherical thick shell immersed in two different spherically symmetric space-times. Using the fact that the boundaries of the thick shell with two embedding space-times must be nonsingular hypersurfaces, we develop a scheme to obtain the underlying equation of motion for the thick shell in general. As a simple example, the equation of motion of

Evgeny Kozik, Boris Svistunov

Kelvin waves (kelvons)--the distortion waves on vortex lines--play a key part in the relaxation of superfluid turbulence at low temperatures. We present a weak-turbulence theory of kelvons. We show that non-trivial kinetics arises only beyond the local-induction approximation and is governed by three-kelvon collisions; corresponding kinetic equation is deriv

J. B. Majer, F. G. Paauw, A. C. J. ter Haar, C. J. P. M. Harmans

We have performed spectroscopy measurements on two coupled flux qubits. The qubits are coupled inductively, which results in a $σ_1^zσ_2^z$ interaction. By applying microwave radiation, we observe resonances due to transitions from the ground state to the first two excited states. From the position of these resonances as a function of the magnetic field appl

Marcos R. S. Tavares, G. -Q. Hai, G. E. Marques

The impurity spectral function is studied in coupled double quantum wires at finite temperatures. Simple anisotropy in the confinement direction of the wires leads to finite non-diagonal elements of the impurity spectral function matrix. These non-diagonal elements are responsible for tunneling effects and result in pronounced extra peak in the impurity spec

Debangshu Chaudhuri, Prashanth W. Menezes, D. D. Sarma

We show that the recently synthesized BF3-doped polyaniline (PANI) exhibits remarkable stability against thermal ageing. Unlike the protonated PANI, which shows rapid degradation of the conductivity on heating in air, BF3-doped PANI shows more than an order of magnitude improvement in conductivity. We employ x-ray photoelectron spectroscopy (XPS), fourier tr

Yue Shen, Shuo Zhang, Nan-xian Chen

The alkali halides have been studied very frequently for their simple structures and interesting properties, for example, the high-pressure induced transition$^1$. There are several successful models that can be employed. The most famous model of them is the Tosi-Fumi interionic potential$^2$ which is an empirical potential derived from the experimental data

E. M. L. Chung, D. McK. Paul, G. Balakrishnan, M. R. Lees

The possibility of magnetic-order induced phonon anisotropy in single crystals of MnO and NiO is investigated using inelastic neutron scattering. Below Tn both compounds exhibit a splitting in their transverse optical phonon spectra of approximately 10%. This behavior illustrates that, contrary to general assumption, the dynamic properties of MnO and NiO are

I. Ferreras, R. F. G. Wyse, J. Silk

The distributions of the stellar metallicities of K giant stars in several fields of the Galactic bulge, taken from the literature are compared with a simple model of star formation and chemical evolution. Our model assumes a Schmidt law of star formation and is described by only a few parameters that control the infall and outflow of gas and the star format

P. M. Vreeswijk, P. Moller, J. P. U. Fynbo

We present near-infrared narrow- and broad-band imaging of the field of GRB021004, performed with ISAAC on the UT1 of the ESO Very Large Telescope. The narrow-band filters were chosen to match prominent emission lines at the redshift of the absorption-line systems found against the early-time afterglow of GRB021004: [OIII] at z=1.38 and Halpha at z=1.60, res