July 2001 arXiv papers — page 12

Alessandro Cuccoli, Andrea Fubini, Valerio Tognetti, Ruggero Vaia

The effects of quantum and thermal fluctuations upon the fringe structure predicted to be observable in the momentum distribution of coupled Bose-Einstein condensates are studied by the effective-potential method. For a double-well trap, the coherence factor recently introduced by Pitaevskii and Stringari [Phys. Rev. Lett. 87, 180402 (2001)] is calculated us

Bastian Kubis, Ulf-G. Meißner

We consider strong and electromagnetic isospin violation in near-threshold pion-kaon scattering. At tree level, such effects are small for all physical channels. We work out the complete one-loop corrections to the process pi^- K^+ -> pi^0 K^0. They come out rather small. We also show that the corresponding radiative cross section is highly suppressed at thr

Enis Tuncer

Accuracy in complex dielectric permittivity calculations in binary dielectric mixtures in two-dimensions are reported by taking into account the shape of the inclusion phase. The dielectric permittivity of the mixtures were calculated using the finite element, and the permittivities were estimated by two different procedures. The results were compared with t

L. Katzarkov, T. Pantev, B. Toen

In this work we use Hodge theoretic methods to study homotopy types of complex projective manifolds with arbitrary fundamental groups. The main tool we use is the \textit{schematization functor} $X \mapsto (X\otimes \mathbb{C})^{sch}$, introduced by the third author as a substitute for the rationalization functor in homotopy theory in the case of non-simply

C. M. Hull

Dual field theory realisations are given for linearised gravity in terms of gauge fields in exotic representations of the Lorentz group. The field equations and dual representations are discussed for a wide class of higher spin gauge fields. For non-linear Einstein gravity, such transformations can be implemented locally in light-cone gauge, or partially imp

Martin Bucher

Much work has been devoted to the phenomenology and cosmology of the so-called braneworld universe, where our (3+1)-dimensional universe lies on a brane surrounded by a (4+1)-dimensional bulk spacetime that is essentially empty except for a negative cosmological constant and the various modes associated with gravity. For such a braneworld cosmology, the diff

O. Blanch, J. Lopez, M. Martinez

The actual potential of the next generation of Gamma Ray Telescopes in improving the existing tests of an effective Quantum Gravity scale from the study of the propagation delay for gamma rays of different energies coming from a distant astrophysical source is discussed. It is shown that the existence of a cosmological Gamma Ray Horizon, will impose very dem

Baruch Horovitz, Anatoly Golub

Broken time reversal symmetry (BTRS) in d wave superconductors is studied and is shown to yield current carrying surface states. The corresponding spontaneous magnetization is temperature independent near the critical temperature Tc for weak BTRS, in accord with recent data. For strong BTRS and thin films we expect a temperature dependent spontaneous magneti

P. Valageas

Using a non-perturbative method developed in a previous article (paper II) we investigate the tails of the probability distribution $P(ρ_R)$ of the overdensity within spherical cells. We show that our results for the low-density tail of the pdf agree with perturbative results when the latter are finite (up to the first subleading term), that is for power-spe

Alekhin Sergey

We perform the analysis of the existing inclusive deep inelastic scattering (DIS) data within NNLO QCD approximation. The parton distributions functions (PDFs) and the value of strong coupling constant $α_{s}(M_Z)=0.1143\pm0.0013 (exp)$ are obtained. The sensitivity of the PDFs to the uncertainty in the value of the NNLO corrections to the splitting function

Fumihiko Sugino, Pierre Vanhove

We analyse supermembrane instantons (fully wrapped supermembranes) by computing the partition function of the three-dimensional supersymmetrical U(N) matrix model under periodic boundary conditions. By mapping the model to a cohomological field theory and considering a mass-deformation of the model, we show that the partition function exactly leads to the U-

Y. Dabaghian, R. V. Jensen, R. Blümel

Based on quantum graph theory we establish that the ray-splitting trace formula proposed by Couchman {\it et al.} (Phys. Rev. A {\bf 46}, 6193 (1992)) is exact for a class of one-dimensional ray-splitting systems. Important applications in combinatorics are suggested.

R. Blümel, Yu. Dabaghian, R. V. Jensen

We identify a set of quantum graphs with unique and precisely defined spectral properties called {\it regular quantum graphs}. Although chaotic in their classical limit with positive topological entropy, regular quantum graphs are explicitly solvable. The proof is constructive: we present exact periodic orbit expansions for individual energy levels, thus obt

Masanao Ozawa

Axiomatic approach to measurement theory is developed. All the possible statistical properties of apparatuses measuring an observable with nondegenerate spectrum allowed in standard quantum mechanics are characterized.

Sibasish Ghosh, Guruprasad Kar, Anirban Roy, Ujjwal Sen

We provide an alternative simple proof of the necessity of entanglement in quantum teleportation by using the no-disentanglement theorem. We show that this is true even when the state to be teleported is known to be among two noncommuting qubits. We further show that to teleport any set of commuting qubits, it is sufficient to have a classically correlated c

Joel M. Williams

The spdf-based orbital theory is a sophism. Things must be declared "different" at the electronic level to renounce classical physics. This paper shows that classical physics still operates at the electronic level! Electron particles are always there. Mass-to-wave/energy conversion and its reversal (duality) on-demand does not actually exist - a ruse

V. Baryshevsky, K. Batrakov, A. Gurinovich, I. Ilienko

First lasing of volume free electron laser (VFEL) is described. The generating system consists of two metal diffraction grating with different spatial periods. The first grating creates the conditions for Smith Purcell emission mechanism. The second grating provides the distributed feedback for emitted wave. The length of diffraction grating is 10 cm. Electr

Evgueni V. Kovarski

The near resonant cooling mechanism have offered for the experiment with laser induced excitation of Lithium isotopes and its ionization by collisions.

J. W. van Holten

Classical particle mechanics on curved spaces is related to the flow of ideal fluids, by a dual interpretation of the Hamilton-Jacobi equation. As in second quantization, the procedure relates the description of a system with a finite number of degrees of freedom to one with infinitely many degrees of freedom. In some two-dimensional fluid mechanics models a

A. Meucci, C. Giusti, F. D. Pacati

We develop a fully relativistic DWIA model for photonuclear reactions using the relativistic mean field theory for the bound state and the Pauli reduction of the scattering state which is calculated from a relativistic optical potential. Results for the 12C(gamma,p) and 16O(gamma,p) differential cross sections and photon asymmetries are displayed in a photon

Makito Oi, Philip M. Walker

We report a solution of the tilted-axis cranked HFB equation for $^{164}$Hf, which shows wobbling motion coupled to gamma vibration at high spin ($J\simeq 60\hbar$). Possible anharmonicity and splitting of energy levels are also discussed as a consequence of the wobbling motion with large amplitude.

Guillermo Abramson, Alan R. Bishop, V. M. Kenkre

Memory effects in transport require, for their incorporation into reaction diffusion investigations, a generalization of traditional equations. The well-known Fisher's equation, which combines diffusion with a logistic nonlinearity, is generalized to include memory effects and traveling wave solutions of the equation are found. Comparison is made with al

Mason A. Porter

Every physical regime is some sort of approximation of reality. One lesser-known realm that is the semiquantal regime, which may be used to describe systems with both classical and quantum subcomponents. In the present review, we discuss nonadiabatic dynamics in the semiquantal regime. Our primary concern is electronic-nuclear coupling in polyatomic molecule

Jean-Guy Caputo, Andrei Maimistov

We consider in the unidirectional approximation the propagation of an ultra short electromagnetic pulse in a resonant medium consisting of molecules characterized by a transition operator with both diagonal and non-diagonal matrix elements. We find the zero-curvature representation of the reduced Maxwell-Bloch equations in the sharp line limit. This can be u

Rebecca Goldin, Tara S. Holm

We show that for a Hamiltonian action of a compact torus $G$ on a compact, connected symplectic manifold $M$, the $G$-equivariant cohomology is determined by the residual $S^1$ action on the submanifolds of $M$ fixed by codimension-1 tori. This theorem allows us to compute the equivariant cohomology of certain manifolds, which have pieces that are four-dimen

T. H. Baker, P. J. Forrester

A bijection is given between fixed point free involutions of $\{1,2,...,2N\}$ with maximum decreasing subsequence size $2p$ and two classes of vicious (non-intersecting) random walker configurations confined to the half line lattice points $l \ge 1$. In one class of walker configurations the maximum displacement of the right most walker is $p$. Because the s

Yasuyuki Kawahigashi

We study the recent construction of subfactors by Rehren which generalizes the Longo-Rehren subfactors. We prove that if we apply this construction to a non-degenerately braided subfactor N subset M and alpha-induction, then the resulting subfactor is dual to the Longo-Rehren subfactor M tensor M^opp subset R arising from the entire system of irreducible end

P. J. Forrester, D. S. McAnally, Y. Nikoyalevsky

The Jack polynomials with prescribed symmetry are obtained from the nonsymmetric polynomials via the operations of symmetrization, antisymmetrization and normalization. After dividing out the corresponding antisymmetric polynomial of smallest degree, a symmetric polynomial results. Of interest in applications is the value of the latter polynomial when all th

A. Garrison, R. Scott

Let P be the right-angled dodecahedron or 120-cell in hyperbolic space, and let W be the group generated by reflections across codimension-one faces of P. We prove that if Gamma is a torsion-free subgroup of minimal index in W, then the corresponding hyperbolic manifold H^n/Gamma is determined up to homeomorphism by Gamma (modulo symmetries of P).

Luiz C. de Albuquerque, R. M. Cavalcanti

We call attention to a series of mistakes in a paper by S. Nam [JHEP 10 (2000) 044, hep-th/0008083].

S. Mahieu, P. Ruelle

We consider the isotropic two-dimensional abelian sandpile model from a perspective based on two-dimensional (conformal) field theory. We compute lattice correlation functions for various cluster variables (at and off criticality), from which we infer the field-theoretic description in the scaling limit. We find a perfect agreement with the predictions of a

A. Bassetto, G. Nardelli, A. Torrielli

We perform a perturbative ${\cal O}(g^4)$ Wilson loop calculation for the U(N) Yang-Mills theory defined on non-commutative one space - one time dimensions. We choose the light-cone gauge and compare the results obtained when using the Wu-Mandelstam-Leibbrandt ($WML$) and the Cauchy principal value ($PV$) prescription for the vector propagator. In the $WML$

Jan Bartelski, Stanislaw Tatur

In order to obtain polarised parton densities we have made next to leading order QCD fit using experimental data on deep inelastic structure functions on nucleons. This fit is compared with the updated fit to coresponding spin asymmetries. We get very similar results for all fits also for different data samples. It seems that only polarised parton densities

Sofiane Tafat

We study power corrections to the event shapes in $\e^+\e^--$annihilation in the two jets kinematical region, $e\ll 1$. We argue that for $e \sim Λ_{QCD}/Q$ all power corrections of the form $1/\lr{Qe}^n$ have to be taken into account for an arbitrary $n$. This is achieved by introducing a new universal distribution, the shape function, which describes the e

F. N. Ndili

We report our finding of a two scale cut off structure in the infrared nonperturbative dynamics of Pade couplant QCD, in the flavor states $N_{f} \le 8$. We argue that these two NPQCD momentum scales $Q_{c}(Y_{1})$ and $Q_{c}(Y_{2})$ can be identified as the scales of onset of chiral symmetry breaking and quark confinement in QCD, and as the cut off boundari

Xiang-Qian Luo

I extend to QCD an efficient method for lattice gauge theory with dynamical fermions. Once the eigenvalues of the Dirac operator and the density of states of pure gluonic configurations at a set of plaquette energies (proportional to the gauge action) are computed, thermodynamical quantities deriving from the partition function can be obtained for arbitrary

L. Bellantoni

Recent results are presented for (1) the charge asymmetry in semielectronic kaon decay; (2) the charge radius of the neutral kaon; (3) the decay Klong -> pi0 pi0 e+e-; (4) constraints on rho(CKM) from kaon decays; (5) lepton flavor violation. A few words about future kaon physics work at Fermilab are included.

Paul F. Derwent, Bogdan A. Dobrescu, Andreas S. Kronfeld, Heather E. Logan

We report on a study of the physics potential of linear $e^+e^-$ colliders. Although a linear collider (LC) would support a broad physics program, we focus on the contributions that could help elucidate the origin of electroweak symmetry breaking. Many extensions of the standard model have a decoupling limit, with a Higgs boson similar to the standard one an

G. Lambiase

Quantum gravitational fluctuations of the space-time background, described by virtual D branes, may induce neutrino oscillations if a tiny violation of the Lorentz invariance (or a violation of the equivalence principle) is imposed. In this framework, the oscillation length of massless neutrinos turns out to be proportional to M/E^2, where E is the neutrino

Spyros S. Kouris

We present an expression for the Weyl-Weyl two-point function in de Sitter spacetime, based on a recently calculated covariant graviton two-point function with one gauge parameter. We find that the Weyl-Weyl two-point function falls off with distance like r^{-4}, where r is spacelike coordinate separation between the two points.

J. C. Evans, P. M. Alsing, S. Giorgetti, K. K. Nandi

We consider the propagation of massive-particle de Broglie waves in a static, isotropic metric in general relativity. We demonstrate the existence of an index of refraction that governs the waves and that has all the properties of a classical index of refraction. We confirm our interpretation with a WKB solution of the general-relativistic Klein-Gordon equat

Erik D. Demaine, Martin L. Demaine, Anna Lubiw, Joseph O'Rourke

We pose and answer several questions concerning the number of ways to fold a polygon to a polytope, and how many polytopes can be obtained from one polygon; and the analogous questions for unfolding polytopes to polygons. Our answers are, roughly: exponentially many, or nondenumerably infinite.

Erik D. Demaine, David Eppstein, Jeff Erickson, George W. Hart

We present two algorithms for unfolding the surface of any polyhedron, all of whose faces are triangles, to a nonoverlapping, connected planar layout. The surface is cut only along polyhedron edges. The layout is connected, but it may have a disconnected interior: the triangles are connected at vertices, but not necessarily joined along edges.

Tobias Baier, Eike Bick, Christof Wetterich

We compute the correlation functions for antiferromagnetic and d-wave superconducting fermion bilinears in a generalized mean field type approximation for the Hubbard model. For high temperature our explicit expressions show that homogeneous field configurations are preferred for these composite bosons. Below a critical temperature we find spontaneous symmet

Wei-Min Zhang

In this letter, I develop a new topologically invariant coherent state path integral for spin systems, and apply it to the quantum Heisenberg model on a square lattice. As a result, the quantum nonlinear $σ$ model for arbitrary values of spin can be directly obtained. The effective coupling constant and spin wave velocity are modified by $g_s= {2\over S}\sqr

Yu. G. Semenov

We suggest an approach to the problem of free electron spin evolution in a semiconductor with arbitrary anisotropy or quantum structure in a magnetic field. The developed approach utilizes quantum kinetic equations for average spin components. These equations represent the relaxation in terms of correlation functions for fluctuating effective fields responsi

I. L. Aleiner, Vladimir I. Fal'ko

The effects of interplay between spin-orbit coupling and Zeeman splitting on weak localisation and universal conductance fluctuations in lateral semiconductor quantum dots are analysed: All possible symmetry classes of corresponding random matrix theories are listed and crossovers between them achievable by sweeping magnetic field and changing the dot parame

H. Schomerus, M. Titov, P. W. Brouwer, C. W. J. Beenakker

We calculate the probability distribution of the local density of states $ν$ in a disordered one-dimensional conductor or single-mode waveguide, attached at one end to an electron or photon reservoir. We show that this distribution does not display a log-normal tail for small $ν$, but diverges instead $\proptoν^{-1/2}$. The log-normal tail appears if $ν$ is

H. -J. Mikeska, M. Mueller

We have studied dimerized spin systems by realizing the cluster expansion to high order. We have extended our previous dimer expansion for one-dimensional systems to cover weakly interacting chains for a quantitative description of three dimensional materials like PHCC and KCuCl_3. By comparison with recent inelastic neutron scattering data we are able to de

K. R. Elder, Mark Katakowski, Mikko Haataja, Martin Grant

A new model of crystal growth is presented that describes the phenomena on atomic length and diffusive time scales. The former incorporates elastic and plastic deformation in a natural manner, and the latter enables access to times scales much larger than conventional atomic methods. The model is shown to be consistent with the predictions of Read and Shockl

Jean-Louis Pichard, Giuliano Benenti, Georgios Katomeris, Franck Selva

The quantum-classical crossover from the Fermi liquid towards the Wigner solid is numerically revisited, considering small square lattice models where electrons interact via a Coulomb U/r potential. We review a series of exact numerical results obtained in the presence of weak site disorder for fully polarized electrons (spinless fermions) and when the spin

G. Zwicknagl, A. N. Yaresko, P. Fulde

We propose a microscopic description of heavy fermions in UPt_3. It is based on the assumption that two of the three 5f electrons of the U ions are localized. Band-structure calculations based on this supposition reproduce the observed de Haas-van Alphen frequencies very well. The observed enhancement of the quasiparticle mass as compared with the LDA band m

Tatsuya Nagao, Jun-ichi Igarashi

We theoretically investigate the origin of the resonant x-ray scattering (RXS) signal near the Ce $L_{III}$ absorption edge in the quadrupolar ordering phase of CeB$_6$, considering the intersite interaction between the $Γ_8$ states in the initial state. The anisotropic charge distribution of the $4f$ states modulates the $5d$ states through the intra-atomic

Anton Bovier, Francesco Manzo

We consider Glauber dynamics of classical spin systems of Ising type in the limit when the temperature tends to zero in finite volume. We show that information on the structure of the most profound minima and the connecting saddle points of the Hamiltonian can be translated into sharp estimates on the distribution of the times of metastable transitions betwe

J. S. Lee, Y. S. Lee, T. W. Noh, K. Char

We investigated the electronic structures of the bandwidth-controlled ruthenates, Y$_{2}$Ru$_{2}$O$_{7}$, CaRuO$_{3}$, SrRuO$_{3}$, and Bi$_{2}$Ru$% _{2}$O$_{7}$, by optical conductivity analysis in a wide energy region of 5 meV $\sim $ 12 eV. We could assign optical transitions from the systematic changes of the spectra and by comparison with the O 1$s$ x-r

David Djajaputra, Bernard R. Cooper

We have used a full-potential linear muffin-tin orbital method to calculate the effects of oxygen impurities on the electronic structure of NiAl. Using the supercell method with a 16-atom supercell we have investigated the cases where an oxygen atom is substitutionally placed at either a nickel or an aluminum site. Full relaxation of the atoms within the sup

J. F. Lara

The effect of the heating of neutrinos by scattering with electrons and positrons and by e-e+ annihilation on nucleosynthesis is calculated for a spherically symmetric baryon inhomogeneous model of the universe. The model has a high baryon density core and a low density outer region. The heating effect is calculated by solving the Boltzmann Transport Equatio

L. V. E. Koopmans, R. D. Blandford

We analyse the kinematics of the entire spectroscopic sample of 99 recently discovered high proper-motion white dwarfs by Oppenheimer et al. using a maximum-likelihood analysis, and discuss the claim that the high-velocity white dwarfs are members of a halo population with a local density at least ten times greater than traditionally assumed. We argue that t

Julian H. Krolik, Gerard A. Kriss

Although soft X-ray absorption features in AGN were discovered almost ten years ago, the nature and location of the gas creating them has remained controversial. Guided by the results of recent high-resolution X-ray spectroscopy, we argue that these features are created in a multi-temperature wind whose source of matter is photoionized evaporation from the i

A. M. Hopkins, M. J. Irwin, A. J. Connolly

The global star formation rate (SFR) density is estimated from the star formation histories (SFHs) of Local Group galaxies. This is found to be broadly consistent with estimates of the global SFH from existing redshift surveys for two favoured cosmologies. It also provides additional evidence for a relatively constant global SFR density at high redshift (z>1

Koji Mukai, Alan P. Smale, Caroline K. Stahle, Eric M. Schlegel

MS 1603.6+2600 is a high-latitude X-ray binary with a 111 min orbital period, thought to be either an unusual cataclysmic variable or an unusual low-mass X-ray binary. In an ASCA observation in 1997 August, we find a burst, whose light curve suggests a Type I (thermonuclear flash) origin. We also find an orbital X-ray modulation in MS 1603.6+2600, which is l

Carl Heiles, Phil Perillat, Michael Nolan, Duncan Lorimer

Modern digital crosscorrelators permit the simultaneous measurement of all four Stokes parameters. However, the results must be calibrated to correct for the polarization transfer function of the receiving system. The transfer function for any device can be expressed by its Mueller matrix. We express the matrix elements in terms of fundamental system paramet

Hans Zinnecker

Most young low-mass stars are born as binary systems, and circumstellar disks have recently been observed around the individual components of proto-binary systems (e.g. L1551-IRS5). Thus planets and planetary systems are likely to form around the individual stellar components in sufficiently wide binary systems. However, a good fraction of planets born in bi

Sydney A. Barnes

The rotation periods of the host stars of extrasolar planets have been assessed against those of the Mt. Wilson stars, open cluster stars, and evolutionary stellar models that include rotation. They appear to be normal, modulo certain inconsistencies in various necessary inputs. Selection of candidate planet hosts for radial velocity surveys by low rotation

Carl Heiles, Phil Perillat, Michael Nolan, Duncan Lorimer

We describe a scheme that characterizes the main beam and sidelobe in all Stokes parameters employing parameters that allow reconstruction of the complete beam patterns and, also, afford an easy way to see how the beam changes with azimuth, zenith angle, and time. For the main beam in Stokes I the parameters include the beam width, ellipticity and its orient

Fiona Hoyle, P. J. Outram, T. Shanks, B. J. Boyle

We describe a method from which cosmology may be constrained from the 2QZ Survey. By comparing clustering properties parallel and perpendicular to the line of sight and by modeling the effects of redshift space distortions, we are able to study geometric distortions in the clustering pattern which occur if a wrong cosmology is assumed when translating redshi

Sara L. Ellison, Lin Yan, Isobel M. Hook, Max Pettini

We present the first results from the Complete Optical and Radio Absorption Line System (CORALS) survey for Damped Lyman Alpha (DLA) systems based on a radio-selected sample of quasars. We find that the number density and neutral gas content of CORALS DLAs is in good agreement with previous surveys. These results indicate that dust obscuration has probably n

Dinshaw Balsara, Robert A. Benjamin, Donald P. Cox

(Abridged) We present the results of three dimensional calculations for the MHD evolution of an adiabatic supernova remnant in both a uniform and turbulent interstellar medium using the RIEMANN framework of Balsara. In the uniform case, which contains an initially uniform magnetic field, the density structure of the shell remains largely spherical, while the

Ata Sarajedini, Jeffrey Van Duyne

We present deep color-magnitude diagrams (CMDs) for a field along the outer disk of M31 based on archival Hubble Space Telescope Wide Field Planetary Camera 2 observations in the F555W (~V) and F814W (~I) filters. The CMDs, which contain a total of about 50,000 stars, feature a prominent red giant branch (RGB) along with a significant population of helium bu

Danny Steeghs, Jorge Casares

We present the first detection of the mass donor star in the prototype X-ray binary Scorpius X-1. Phase resolved spectroscopy revealed narrow emission lines components from the irradiated secondary star. Radial velocity fits to the Bowen blend emission are used to establish an absolute orbital ephemeris and derive an accurate value for the systemic velocity;

Charles R. Keeton

The statistics of gravitationally lensed arcs, which can be used for a variety of cosmological tests, are sensitive to the intrinsic shapes of the source galaxies. I present an analytic formalism that makes it simple to include elliptical sources in analytic calculations of lens statistics. For cuspy lens models, sources with an axis ratio of 2:1 enhance the

Barton J. Pritzl, Horace A. Smith, Marcio Catelan, Allen V. Sweigart

We have undertaken a search for variable stars in the metal-rich globular cluster NGC 6441 using time-series BV photometry. The total number of variables found near NGC 6441 has been increased to ~104, with 48 new variables being found in this survey. A significant number of the variables are RR Lyrae stars (~46), most of which are probable cluster members.

E. Daddi, T. Broadhurst, G. Zamorani, A. Cimatti

We examine the spatial clustering of extremely red objects (EROs) found in a relatively large survey of 700 arcmin^2, containing 400 galaxies with R-Ks>5 to Ks=19.2. A comoving correlation length r_0=12\pm3 /h Mpc is derived, under the assumption that the selection function is described by a passively evolving early-type galaxy population, with an effective

S. De Rijcke, H. Dejonghe, W. W. Zeilinger, G. K. T. Hau

We present major and minor axis kinematics out to 2 half-light radii for the bright (M_B=-16.7) dwarf elliptical FS76, a member of the NGC5044 group. Its velocity dispersion is 46 \pm 2 km/s in the center and rises to 70 \pm 10 km/s at half-light radius. Beyond 1R_e the dispersion starts to fall again. The maximum rotation velocity is 15 \pm 6 km/s, about th

T. Oosterbroek, A. N. Parmar, L. Sidoli, J. J. M. in 't Zand

Results of a 2000 August 12-13 BeppoSAX observation of the 7.1 hr eclipsing, dipping, bursting, transient, low-mass X-ray binary (LMXRB) X1658-298 are presented. The spectrum outside of eclipses, dips and bursts can be modeled by the combination of a soft disk-blackbody and a harder Comptonized component with a small amount (1.3 10E21 atom/cm2) of low-energy

T. Augusteijn, E. Kuulkers, M. H. van Kerkwijk

We present K band photometry of the region including the radio error box of the soft X-ray transient 4U 1630-47 during its 1998 outburst. We detect a variable source at K=16.1 mag located inside the radio error circle which we identify as the counterpart to the X-ray source. We discuss the properties of the source, and conclude that it is most likely a black

Paula Szkody, Boris Gaensicke, Robert E. Fried, Uli Heber

Photometric and spectroscopic observations of the candidate cataclysmic variable KUV03580+0614, independently found from the Hamburg survey as HS0357+0614, reveal this to be a cataclysmic variable with an orbital period of 3.4 hrs. CVs with periods in this range are usually novalikes belonging to the SW Sex or Intermediate Polar categories. The variability,

A. Reiners, J. H. M. M. Schmitt, M. Kuerster

We report detection of differential rotation on the F5 dwarf psi Cap using line profile analysis. The Fourier transform of both FeI lambda 5775 and SiI lambda 5772 are used to obtain a projected rotational velocity of v sini = (42+-1)km/s. Modelling of the Fourier transformed profiles shows that the combined effects of equatorial velocity, inclination and di

A. Yoshida, M. Namiki, D. Yonetoku, T. Murakami

A gamma-ray burst of 28 August 1997 was localized by the All-Sky Monitor on the Rossi XTE satellite and its coordinates were promptly disseminated. An ASCA followup started 1.17 days after the burst as a Target of Opportunity Observation and detected an X-ray afterglow. The spectral data displayed a hump around ~5 keV and an absorption column of 7.1 x 10^21

D. Yonetoku, T. Murakami, K. Masai, A. Yoshida

Iron spectral features are thought to be the best tracer of a progenitor of gamma-ray bursts (GRBs). The detections of spectral features such as an iron line and/or a Radiative Recombination edge and Continuum (RRC) were reported in four X-ray afterglows of GRBs. However their properties were different each other burst by burst. For example, Chandra observat

D. Porquet, R. Mewe, J. Dubau, A. J. J. Raassen

The line ratios R and G of the three main lines of He-like ions (triplet: resonance, intercombination, forbidden lines) are calculated for CV, NVI, OVII, NeIX, MgXI, and SiXIII. These ratios can be used to derive electron density n_e and temperature T_e of hot late-type stellar coronae and O, B stars from high-resolution spectra obtained with Chandra (LETGS,

Carl Heiles

Modern digital correlators permit the simultaneous measurement of all four Stokes parameters using auto and crosscorrelation. We briefly outline the fundamental requirements and some practical details of performing such measurements and refer to two additional papers that provide overview and cover calibration issues in detail.

Carl Heiles

Radio sources are often polarized. Accurate measurement of simply the flux density of a radio source requires a basic understanding of polarization and its measurement techniques. We provide an introductory, heuristic discussion of these matters with an emphasis on practical application and avoiding pitfalls.

Stacy McGaugh, Vera Rubin, Erwin de Blok

We present long slit Halpha observations of 50 low surface brightness galaxies. Of these, 36 are of sufficient quality to form rotation curves. These data provide a large increase in the number of low surface brightness galaxies for which accurate rotation curves are available. They also represent an order of magnitude improvement in spatial resolution over

C. A. Terrero-Escalante, A. A. Garcia

Recently an inflationary potential yielding power spectra characterized by a scale-invariant tensorial spectral index and a scale-dependent scalar spectral index was introduced. We analize here the implications that this potential could have for the large-scale structure formation in the multiverses scenario of eternal inflation.

A. I. Arbab

We have obtained empirical laws for the variation of the Earth parameters with geologic time that are in agreement with coral fossil data obtained by Wells and Runcorn. Our model predicts that the day is lengthening at a rate of 2 ms/century at the present time. The length of the day when the Earth was formed is found to be 6 hours and the synodic month to b

Philip J. Armitage, Mario Livio, S. H. Lubow, J. E. Pringle

Withdrawn in current form.

Victoria I. Fernández, Aníbal Iucci, Carlos M. Naón

Paper withdrawn by authors. See new version in this same listing.

Mirjam Cvetic, Gary Shiu, Angel M. Uranga

We construct the first three family N=1 supersymmetric string model with Standard Model gauge group SU(3)_C x SU(2)_L x U(1)_Y from an orientifold of type IIA theory on T^6/(Z_2 x Z_2) and D6-branes intersecting at angles. In addition to the minimal supersymmetric Standard Model particles, the model contains right-handed neutrinos, a chiral (but anomaly-free

CLAS Collaboration, S. Stepanyan

We report the first results of the beam spin asymmetry measured in the reaction e + p -> e + p + gamma at a beam energy of 4.25 GeV. A large asymmetry with a sin(phi) modulation is observed, as predicted for the interference term of Deeply Virtual Compton Scattering and the Bethe-Heitler process. The amplitude of this modulation is alpha = 0.202 +/- 0.028. I

Sergei F. Shandarin

The assumption of Gaussianity of the primordial perturbations plays an important role in modern cosmology. The most direct test of this hypothesis consists in testing Gaussianity of the CMB maps. Counting the pixels with the temperatures in given ranges and thus estimating the one point probability function of the field is the simplest of all the tests. Othe

H. E. Puthoff, S. R. Little, M. Ibison

A theme that has come to the fore in advanced planning for long-range space exploration is the concept of "propellantless propulsion" or "field propulsion." One version of this concept involves the projected possibility that empty space itself (the quantum vacuum, or space-time metric) might be manipulated so as to provide energy/thrust for f

Tesla E. Jeltema, Claude R. Canizares, Mark W. Bautz, Michael R. Malm

We observed MS 1054-0321, the highest redshift cluster of galaxies in the Einstein Medium Sensitivity Survey (EMSS), with the Chandra ACIS-S detector. We find the X-ray temperature of the cluster to be 10.4 +1.7 -1.5 keV, lower than, but statistically consistent with, the temperature inferred previously. This temperature agrees well with the observed velocit

Paolo Creminelli, Alberto Nicolis, Riccardo Rattazzi

We study through holography the compact Randall-Sundrum (RS) model at finite temperature. In the presence of radius stabilization, the system is described at low enough temperature by the RS solution. At high temperature it is described by the AdS-Schwarzschild solution with an event horizon replacing the TeV brane. We calculate the transition temperature T_

Zeng-Bing Chen, Yong-De Zhang

We demonstrate that two coupled Bose-Einstein condensates (BEC) at zero temperature can be used to realize a qubit which is the counterpart of Josephson charge qubits. The two BEC are weakly coupled and confined in an asymmetric double-well trap. When the "charging energy" of the system is much larger than the Josephson energy and the system is biase

Nathan Berkovits, Sergei Gukov, Brenno Carlini Vallilo

The hybrid formalism is used to quantize the superstring compactified to two-dimensional target-space in a manifestly spacetime supersymmetric manner. A quantizable sigma model action is then constructed for the Type II superstring in curved two-dimensional supergravity backgrounds which can include Ramond-Ramond flux. Such curved backgrounds include Calabi-

F. Krzakala, J. Houdayer, E. Marinari, O. C. Martin

We probe the energy landscape of the 3D Edwards-Anderson spin glass in a magnetic field to test for a spin glass ordering. We find that the spin glass susceptibility is anomalously large on the lattice sizes we can reach. Our data suggest that a transition from the spin glass to the paramagnetic phase takes place at B_c=0.65, though the possibility B_c=0 can

D. F. Roscoe

We consider the four large optical rotation curve samples of Mathewson, Ford & Buchhorn (900 ORCs), Mathewson & Ford (1200 ORCs), Dale, Giovanelli, Haynes et al (494 ORCs) and Courteau (300 ORCs). We show how it is possible to partition any given ORC into two distinct dynamical regions - an interior region and an exterior region. Each of the samples consider

Tsung-Wen yeh

In many years ago, Isgur and Llewellyn Smith addressed that PQCD is inapplicable to exclusive processes, such as the pion form factor.The main problem is that the asymptotic of PQCD is only about one fourth of the experimental value. We reexamine this PQCD deep problem. By including NLO power corrections to the pion form factor, we may arrive at a perturbati

J. Hwang, T. Padmanabhan, O. Lahav, H. Noh

We point out that a pseudo-Newtonian interpretations of the $(1/3)$ factor in the Sachs-Wolfe effect, which relates the fluctuations in temperature and potential, $(δT/ T) = (1/ 3) δΦ$, is not supported by the General Relativistic analysis. Dividing the full gravitational effect into separate parts depends on the choice of time slicing (gauge) and there exis