August 2004 arXiv papers — page 16
Showing 1,501–1,600 of 3,254 papers
Bertrand Duplantier
We consider a model of a D-dimensional tethered manifold interacting by excluded volume in R^d with a single point. Use of intrinsic distance geometry provides a rigorous definition of the analytic continuation of the perturbative expansion for arbitrary D, 0 < D < 2. Its one-loop renormalizability is first established by direct resummation. A renormalizatio
A. L. Kuzemsky
Theoretical foundations and applications of the generalized spin-fermion (sp-d) exchange lattice model to various magnetic systems, e.g. rare-earth metals and compounds and magnetic semiconductors are discussed. The capabilities of the model to describe spin quasi-particle spectra are investigated. The main emphasis is made on the dynamical behavior of two i
M. Lopez de Haro, C. F. Tejero
The demixing transition of a binary fluid mixture of additive hard spheres is analyzed for different size asymmetries by starting from the exact low-density expansion of the pressure. Already within the second virial approximation the fluid separates into two phases of different composition with a lower consolute critical point. By successively incorporating
Gordon Baym
How does a rapidly rotating condensed Bose gas carry extreme amounts of angular momentum? The energetically favored state of a not-too-rapidly rotating Bose condensed gas is, as observed, a triangular lattice of singly quantized vortices. This paper describes the fates of the vortex lattice in both harmonic and anharmonic traps when condensates are rotated e
Electronic Raman scattering in correlated materials: exact treatment of nonresonant, mixed, and resonant scattering with dynamical mean field theory
cond-mat.str-elA. M. Shvaika, O. Vorobyov, J. K. Freericks, T. P. Devereaux
We solve for the electronic Raman scattering response functions on an infinite-dimensional hypercubic lattice employing dynamical mean field theory. This contribution extends previous work on the nonresonant response to include the mixed and resonant contributions. We focus our attention on the spinless Falicov-Kimball model, where the problem can be solved
M. Morelle, D. S. Golubovic, V. V. Moshchalkov
We study the evolution of the superconducting state in a perforated disk by varying the size of the hole. The superconducting properties are investigated by means of transport measurements around the superconducting/normal phase boundary Tc(H). A transition from a one-dimensional to a two-dimensional regime is seen when increasing the magnetic field for disk
Half-magnetization plateau stabilized by structural distortion in the antiferromagnetic Heisenberg model on a pyrochlore lattice
cond-mat.str-elK. Penc, N. Shannon, H. Shiba
Magnetization plateaus, visible as anomalies in magnetic susceptibility at low temperatures, are one of the hallmarks of frustrated magnetism. We show how an extremely robust half-magnetization plateau can arise from coupling between spin and lattice degrees of freedom in a pyrochlore antiferromagnet, and develop a detailed symmetry of analysis of the simple
Sumio Ishihara
Hole dynamics in spin and orbital ordered vanadates with perovskite structure is investigated. A mobile hole coupled to the spin excitation (magnon) in the spin G-type and orbital C-type (SG/OC) ordered phase, and that to the orbital excitation (orbiton) in the spin C-type and orbital G-type (SC/OG) one are formulated on an equal footing. The observed fragil
CO adsorption on Cu(111) and Cu(001) surfaces: improving site preference in DFT calculations
cond-mat.mtrl-sciM. Gajdos, J. Hafner
CO adsorption on Cu(111) and Cu(001) surfaces has been studied within ab-initio density functional theory (DFT). The structural, vibrational and thermodynamic properties of the adsorbate-substrate complex have been calculated. Calculations within the generalized gradient approximation (GGA) predict adsorption in the threefold hollow on Cu(111) and in the bri
Critical gaps of first-order phase transition in infinitely long Ising cylinders with antiperiodically joined circumference
cond-mat.stat-mechTsong-Ming Liaw, Ming-Chang Huang, Simon C. Lin, Yu-Pin Luo
Based on the analytic expression of free energy for infinitely long Ising strip with finite width joined antiperiodically on a variety of planar lattices, we show the existence of first-order phase transition at the critical point of Ising transition. The critical gaps of the transition are also calculated analytically by measuring the discontinuities in the
T. Aste, U. Valbusa
We apply a theoretical approach, originally introduced to describe aeolian ripples formation in sandy deserts, to the study of surface instability in ion sputtered surfaces. The two phenomena are distinct by several orders of magnitudes and by several physical mechanisms, but they obey to similar geometrical constraints and therefore they can be described by
Martin Albrecht
The frequency dependence of the self energy of a general many--body problem is identified as a main obstacle in correlation calculations based on local approaches. A frequency independent formulation is proposed instead and proven to yield exactly the same numerical results as the original common scheme. Our approach is embedded in a general local-orbital ba
M. E. Zhitomirsky, Hirokazu Tsunetsugu
Low-energy degrees of freedom of a spin-1/2 kagome antiferromagnet in the vicinity of the saturation field are mapped to a hard-hexagon model on a triangular lattice. The latter model is exactly solvable. The presented mapping allows to obtain quantitative description of the magnetothermodynamics of a quantum kagome antiferromagnet up to exponentially small
Two-time autocorrelation function in phase-ordering kinetics from local scale-invariance
cond-mat.stat-mechMalte Henkel, Alan Picone, Michel Pleimling
The time-dependent scaling of the two-time autocorrelation function of spin systems without disorder undergoing phase-ordering kinetics is considered. Its form is shown to be determined by an extension of dynamical scaling to a local scale-invariance which turns out to be a new version of conformal invariance. The predicted autocorrelator is in agreement wit
J. Sirker, A. Weiße, O. P. Sushkov
In the first part we discuss how the BEC picture for magnons is modified by anisotropies induced by spin-orbit coupling. In particular we focus on the effects of antisymmetric spin interactions and/or a staggered component of the $g$ (gyromagnetic) tensor. Such terms lead to a gapped quasiparticle spectrum and a nonzero condensate density for all temperature
Many-particle localization by constructed disorder: enabling quantum computing with perpetually coupled qubits
cond-mat.mes-hallM. I. Dykman, F. M. Izrailev, L. F. Santos, M. Shapiro
We demonstrate that, in a many-particle system, particles can be strongly confined to their sites. The localization is obtained by constructing a sequence of on-site energies that efficiently suppresses resonant hopping. The time during which a many-particle state remains strongly localized in an infinite chain can exceed the reciprocal hopping frequency by
Heating and atom loss during upward ramps of Feshbach resonance levels in Bose-Einstein condensates
cond-mat.otherThorsten Koehler, Krzysztof Goral, Thomas Gasenzer
The production of pairs of fast atoms leads to a pronounced loss of atoms during upward ramps of Feshbach resonance levels in dilute Bose-Einstein condensates. We provide comparative studies on the formation of these bursts of atoms containing the physical predictions of several theoretical approaches at different levels of approximation. We show that despit
Marc Davis, Brian F. Gerke, Jeffrey A. Newman
The DEEP2 survey has now completed half of its planned three-year lifespan, and we have collected approximately 50% of the data, putting us exactly on schedule. The survey plan calls for spectroscopic coverage by July of 2005 of \~60,000 galaxies over 3.5 square degrees to a limiting magnitude of R_{AB}=24.1; the great majority of these objects are at 0.7<z<
Stefan Westerhoff
We present the results of a search for small-scale anisotropy in the distribution of arrival directions of cosmic rays above 10^19 eV measured in stereo by the High Resolution Fly's Eye (HiRes) experiment. Performing an autocorrelation scan in energy and angular separation, we find that the strongest correlation signal in the HiRes stereo data set record
Metal Abundances of KISS Galaxies III. Nebular Abundances for Fourteen Galaxies and the Luminosity-Metallicity Relationship for HII Galaxies
astro-phJanice C. Lee, John J. Salzer, Jason Melbourne
We report results from the third in a series of nebular abundance studies of emission-line galaxies from the KPNO International Spectroscopic Survey (KISS). Galaxies with coarse metallicity estimates of 12 + log(O/H) less than 8.2 dex were selected for observation. Spectra of 14 galaxies, which cover the full optical region from [OII]3727,3729 to beyond [SII
Evan Scannapieco, Jon Weisheit, Francis Harlow
We investigate the interactions of high-redshift galaxy outflows with low-mass virialized (Tvir < 10,000K) clouds of primordial composition. While atomic cooling allows star formation in larger primordial objects, such "minihalos" are generally unable to form stars by themselves. However, the large population of high-redshift starburst galaxies may h
A. K. H. Kong, L. O. Sjouwerman, B. F. Williams
The supernova remnant (SNR), Ho 12, in the center of the dwarf irregular galaxy NGC 6822 was previously observed at X-ray, optical, and radio wavelengths. By using archival Chandra and ground-based optical data, we found that the SNR is spatially resolved in X-rays and optical. In addition, we obtained a ~5" resolution radio image of the SNR. These obser
Paul L. Schechter
Present day estimates of the Hubble constant based on Cepheids and on the cosmic microwave background radiation are uncertain by roughly 10% (on the conservative assumption that the universe may not be PERFECTLY flat). Gravitational lens time delay measurements can produce estimates that are less uncertain, but only if a variety of major difficulties are ove
Andrew J. Baker, Linda J. Tacconi, Reinhard Genzel, Dieter Lutz
Using the IRAM Plateau de Bure Interferometer, we have searched for CO(3-2) emission from the dusty Lyman break galaxy Westphal-MD11 at z = 2.98. Our sensitive upper limit is surprisingly low relative to the system's 850 um flux density and implies a far-IR/CO luminosity ratio as elevated as those seen in local ultraluminous mergers. We conclude that the
Dwarf Novae with Newly Determined Parallaxes: Model Analyses of VY Aquari, RU Pegasi, and T Leonis
astro-phR. T. Hamilton, E. M. Sion
Using newly determined parallaxes for dwarf novae, we have derived outburst accretion rates for VY Aqr, RU Peg and T Leo and for T Leo during quiescence. The two short-period dwarf novae, VY Aqr and T Leo, show good agreement with optically thick steady-state accretion disks in outburst, whereas RU Peg shows a significant departure from a steady-state disk.
Average UV Quasar Spectra in the Context of Eigenvector 1: A Baldwin Effect Governed by Eddington Ratio?
astro-phR. Bachev, P. Marziani, J. W. Sulentic, R. Zamanov
We present composite UV spectra for low redshift Type 1 AGN binned to exploit the information content of the Eigenvector 1 (E1) parameter space. Composite spectra allow a decomposition of the CIV1549 line profile - one of the strongest high-ionization lines. The simplest CIV decomposition into narrow (NLR), broad (BLR) and very broad (VBLR) components sugges
Thomas M. Brown, Henry C. Ferguson, Ed Smith, Randy A. Kimble
We present a color-magnitude diagram (CMD) of the globular cluster SKHB-312 in the Andromeda galaxy (M31), obtained with the Advanced Camera for Surveys on the Hubble Space Telescope. The cluster was included in deep observations taken to measure the star formation history of the M31 halo. Overcoming a very crowded field, our photometry of SKHB-312 reaches V
An X-ray Outburst from the Rapidly Accreting Young Star That Illuminates McNeil's Nebula
astro-phJ. H. Kastner, M. Richmond, N. Grosso, D. A. Weintraub
Young, low-mass stars are luminous X-ray sources whose powerful X-ray flares may exert a profound influence over the process of planet formation. The origin of such emission is uncertain. Although many or perhaps most recently formed, low-mass stars emit X-rays as a consequence of solar-like coronal activity, it has also been suggested that X-ray emission ma
J. Casares, C. Zurita, T. Shahbaz, P. A. Charles
We present the first radial velocity curve of the companion star to BW Cir which demonstrates the presence of a black hole in this X-ray transient which recorded outbursts in 1987 and 1997 (and possibly 1971-2). We identify weak absorption features corresponding to a G0-5III donor star, strongly veiled by a residual accretion disc which contributes 61-65 % o
G. James, P. Francois, P. Bonifacio, E. Carretta
High resolution (R > 40 000) and high S/N spectra have been acquired with UVES on the VLT-Kueyen (Paranal Observatory, ESO Chile) for several main sequence turnoff stars (V ~ 17 mag) and subgiants at the base of the Red Giant Branch (V ~ 16 mag) in three globular clusters (NGC 6397, NGC 6752 and 47 Tuc/NGC 104) at different metallicities (respectively [Fe/H]
Martin Paetzold, Ludmila Carone, Heike Rauer
Close-in extrasolar planets experience extreme tidal interactions with their host stars. This may lead to a reduction of the planetary orbit and a spin-up of stellar rotation. Tidal interactions have been computed for a number of extrasolar planets in circular orbits within 0.06 AU, namely for OGLE-TR-56 b. We compare our range of the tidal dissipation value
A. Tarchi, C. Henkel, M. Chiaberge, K. M. Menten
We report the first detection of a water megamaser in a radio-loud galaxy, 3C403, and present a follow-up study using the VLA. 3C403 has been observed as a part of a small sample of FRII galaxies with evidence of nuclear obscuration. The isotropic luminosity of the maser is ~1200 solar luminosities. With a recessional velocity of cz~17680 km/s it is the most
H. B. Ann, Parijat Thakur
We have performed SPH simulations for the response of the gaseous disks to the imposed potentials including those from bars and SMBHs. Evolution of the nuclear regions of gaseous disks depends critically on the masses of SMBHs as well as the sound speeds in the gas.
F. Boone, N. Brouillet, S. Huettemeister, C. Henkel
This paper is aimed at providing new insight into the nature and origin of the molecular complex situated near the line of sight toward Holmberg IX in the M81 group of galaxies. The first high resolution CO maps of the complex as well as single dish 13CO(1-0), 12CO(3-2) and millimeter continuum observations and the results of a survey of 12CO in the region a
Georges Meynet, André Maeder, Sylvia Ekström
Rotation deeply affects the evolution of very metal poor massive stars. Indeed, even moderately rotating stars reach the break--up limit during the Main--Sequence (MS) phase, they evolve rapidly to the red after the core H--burning phase and important surface enrichment in CNO elements occurs at the supergiant stage. High rotation and the self enrichment in
M. Juvela, P. Padoan
We present describe a new computer code that solves the radiative transfer problem on multi-resolution grids. If the cloud model is from an MHD simulation on a regular cartesian grid, criteria based for example on local density or velocity gradients are used to refine the grid by dividing selected cells into sub-cells. Division can be repeated hierarchically
André Maeder, Georges Meynet, Raphael Hirschi
We discuss the physics of the $ΩΓ$-- Limit, i.e. when the star is unbound as a result of {\emph{both}} rotation and radiation pressure. We suggest that the $ΩΓ$-- Limit is what makes the Humphreys--Davidson Limit. Stellar filiations are discussed, with an emphasis on the final stages, in particular on the final masses, their angular momentum and the chemical
G. Meynet, A. Maeder
Grids of models of massive stars ($M \ge$ 20 $M_\odot$) with rotation are computed for metallicities $Z$ ranging from that of the Small Magellanic Cloud (SMC) to that of the Galactic Centre. The hydrostatic effects of rotation, the rotational mixing and the enhancements of the mass loss rates by rotation are included. The evolution of the surface rotational
Jungyeon Cho
We present numerical studies of 3-dimensional magnetohydrodynamic (MHD) turbulence in a strongly magnetized medium in the extremely relativistic limit, in which the inertia of the charge carriers can be neglected. We have focused on strong Alfvenic turbulence in the limit. We have found the following results. First, the energy spectrum is consistent with a K
A. Sandoval-Villalbazo, L. S. Garcia-Colin, A. Arrieta
In this paper we study a simple model consisting of a dilute fully ionized plasma in the presence of the gravitational and a constant magnetic field to analyze the propagation of hydromagnetic instabilities. In particular we show that the so called Jeans instability is in principle affected by the presence of the magnetic field. A brief discussion is made at
Levi Lopes de Lima
Whyte used the index theory of Dirac operators and Block-Weiberger uniformly finite homology to show that certain infinite connected sums do not carry a metric with nonnegative scalar curvature in their bounded geometry class. His proof uses a coarse version of the $\hat{A}$-class to obstruct such metrics. In this note we prove a version of Whyte's resul
Werner Rodejohann, Zhi-zhong Xing
We generalize the democratic neutrino mixing Ansatz by incorporating the type-II seesaw mechanism with S(3) flavor symmetry. We find that bilarge neutrino mixing can naturally appear if the flavor democracy contribution is strongly suppressed due to significant cancellation between the conventional seesaw and triplet mass terms. Explicit S(3) symmetry breaki
Andre Gsponer, Jean-Pierre Hurni
The usual action integral of classical electrodynamics is derived starting from Lanczos's electrodynamics -- a pure field theory in which charged particles are identified with singularities of the homogeneous Maxwell's equations interpreted as a generalization of the Cauchy-Riemann regularity conditions from complex to biquaternion functions of four
Marcelo B. Ribeiro
This paper studies the effect of the distance choice in radial (non-average) statistical tools used for fractal characterization of galaxy distribution. After reviewing the basics of measuring distances of cosmological sources, various distance definitions are used to calculate the differential density $γ$ and the integral differential density $γ^\ast$} of t
James F. Davis
Four-dimensional surgery is used to show that a two component link with Alexander polynomial one is topologically concordant to the Hopf link.
A. Doff, A. A. Natale
We discuss the mass splitting between the the top and bottom quarks in a technicolor scenario. The model proposed here contains a left-right electroweak gauge group. An extended technicolor group and mirror fermions are introduced. The top-bottom quark mass splitting turns out to be intimately connected to the breaking of the left-right gauge symmetry. Weak
The K-matrix approach to the Delta - resonance mass splitting and isospin violation in low-energy pi-N scattering
hep-phA. B. Gridnev, I. Horn, W. J. Briscoe, I. I. Strakovsky
The experimental data on pi N scattering in the elastic energy region T_pi < 250 MeV are analyzed within the multichannel K-matrix approach with effective Lagrangians. Isospin invariance is not assumed in this analysis and the physical values for masses of the involved particles are used. The corrections due to pi^+- pi^0 and p-n mass differences are calcula
David Atwood, Shaouly Bar-Shalom, Amarjit Soni
We describe a model for the scalar sector where all interactions occur either at an ultra-high scale L_U ~ 10^{16}-10^{19} GeV or at an intermediate scale L_I ~ 10^{9}-10^{11} GeV. The interaction of physics on these two scales results in an SU(2) Higgs condensate at the electroweak (EW) scale, L_{EW}, through a seesaw-like Higgs mechanism, L_{EW} ~ L_I^2/L_
Yasuaki Hikida, Tadashi Takayanagi
We investigate the SL(2,R)/U(1) WZW model with level 0<k<2 as a solvable time-dependent background in string theory. This model is expected to be dual to the one describing a rolling closed string tachyon with a time-like linear dilaton. We examine its exact metric and minisuperspace wave functions. Two point functions and the one-loop vacuum amplitude are c
Jose Edgar Madriz Aguilar, Mauricio Bellini
Using the Hamilton-Jacobi formalism, we study extra force and extra mass in a recently introduced noncompact Kaluza-Klein cosmological model. We examine the inertial 4D mass $m_0$ of the inflaton field on a 4D FRW bulk in two examples. We find that $m_0$ has a geometrical origin and antigravitational effects on a non inertial 4D bulk should be a consequence
B. M. Gripaios
We construct effective field theories in which gravity is modified via spontaneous breaking of local Lorentz invariance. This is a gravitational analogue of the Higgs mechanism. These theories possess additional graviton modes and modified dispersion relations. They are manifestly well-behaved in the UV and free of discontinuities of the van Dam-Veltman-Zakh
Thorsten Feldmann, Tobias Hurth
We investigate to what extent the experimental information on $B \to ππ$ branching fractions and CP asymmetries can be used to better understand the QCD dynamics in these decays. For this purpose we decompose the independent isospin amplitudes into factorizable and non-factorizable contributions. The former can be estimated within the framework of QCD factor
Yûsuke Okuyama
We show that if a 1-hyperbolic structurally finite entire function of type $(p,q)$, $p\ge 1$, is linearizable at an irrationally indifferent fixed point, then its multiplier satisfies the Brjuno condition. We also prove the generalized Mañé theorem; if an entire function has only finitely many critical points and asymptotic values, then for every such a non-
R. N. Mohapatra
Many experiments are being planned to measure the neutrino mixing parameter $θ_{13}$ using reactor as well as accelerator neutrino beams. In this note, the theoretical significance of a high precision measurement of this parameter is discussed. It is emphasized that it will provide crucial information about different ways to understand the origin of large at
Poisson-Lie T-plurality of three-dimensional conformally invariant sigma models II: Nondiagonal metrics and dilaton puzzle
hep-thL. Hlavaty, L. Snobl
We look for 3-dimensional Poisson-Lie dualizable sigma models that satisfy the vanishing beta-function equations with constant dilaton field. Using the Poisson-Lie T-plurality we then construct 3-dimensional sigma models that correspond to various decompositions of Drinfeld double. Models with nontrivial dilaton field may appear. It turns out that for ``trac
Guray Erkol, Gursevil Turan, Jan Willem Wagenaar
We study the decay rate and the CP violating asymmetry of the exclusive B-> pi ell+ ell- and B-> rho ell+ ell- decays in the case where one of the final leptons is polarized. We calculate the contributions coming from the individual polarization states in order to identify a so-called wrong sign decay, which is a decay with a given polarization, whose width
S. A. Emelyanov
We demonstrate experimentally that in an asymmetric quantum well in presence of quantizing magnetic field tilted in XZ plane, confining potential V(z) lifts Landau level degeneracy related to position of the centers of electron cyclotron orbits along X axis. This results in a transformation of the Landau levels into the bands in which the electrons may posse
Stefan Berceanu
A representation of the Jacobi algebra $\mathfrak{h}_1\rtimes \mathfrak{su}(1,1)$ by first order differential operators with polynomial coefficients on the manifold $\mathbb{C}\times \mathcal{D}_1$ is presented. The Hilbert space of holomorphic functions on which the holomorphic first order differential operators with polynomials coefficients act is construc
Harold Steinacker
This thesis is based on hep-th/0203110, hep-th/0005273, hep-th/0107068, hep-th/0106205, and hep-th/0103164, but includes additional results, details, and background material. It covers the description of D-branes on group manifolds based on quantum groups including the required mathematical background, field theory on the q-deformed fuzzy sphere (both first-
Sergei Sakovich
We show that one of the five cases of a quadratic Hamiltonian, which were recently selected by Sokolov and Wolf who used the Kovalevskaya-Lyapunov test, fails to pass the Painleve test for integrability.
Kathryn Hess, Paul-Eugène Parent, Jonathan Scott, Andrew Tonks
For any 1-reduced simplicial set $K$ we define a canonical, coassociative coproduct on $\Om C(K)$, the cobar construction applied to the normalized, integral chains on $K$, such that any canonical quasi-isomorphism of chain algebras from $\Om C(K)$ to the normalized, integral chains on $GK$, the loop group of $K$, is a coalgebra map up to strong homotopy. Ou
H. Wen, L. S. Kisslinger, Walter Greiner, G. Mao
The effects of strong magnetic fields on the inner crust of neutron stars are investigated after taking into account the anomalous magnetic moments of nucleons. Energy spectra and wave functions for protons and neutrons in a uniform magnetic field are provided. The particle spin polarizations and the yields of protons and neutrons are calculated in a free Fe
Yoshiaki Rikitake, Hiroshi Imamura
We theoretically study decoherence of two localized spins interacting via the RKKY interaction in one-, two-, and three-dimensional electron gas. We derive the kinetic equation for the reduced density matrix of the localized spins and show that energy relaxation caused by singlet-triplet transition is suppressed when the RKKY interaction is ferromagnetic. We
Yutaka Hemmi, Yusuke Kawamoto
We study connected mod p finite A_p-spaces admitting AC_n-space structures with n<p for an odd prime p. Our result shows that if n is greator than (p-1)/2, then the mod p Steenrod algebra acts on the mod p cohomology of such a space in a systematic way. Moreover, we consider A_p-spaces which are mod p homotopy equivalent to product spaces of odd dimensional
Interferometric Observation of the Highly Polarized SiO Maser Emission from the $v=1, J=5-4$ Transition Associated with VY Canis Majoris
astro-phHiroko Shinnaga, James M. Moran, Ken H. Young, Paul T. P. Ho
We used the Submillimeter Array to image the SiO maser emission in the $v=1$, \$J=5-4$ transition associated with the peculiar red supergiant VY Canis Majoris. We identified seven maser components and measured their relative positions and linear polarization properties. Five of the maser components are coincident to within about 150 mas ($\sim$ 200 AU at the
Tai-Kai Ng
Using a phenomenological model, we discuss the consequences of spinon-holon binding in the U(1) slave-boson approach to $t-J$ model. Within a small $x$ ($x=$ hole concentration) expansion, we show that spinon-holon binding produces a pseudo-gap normal state with a segmented Fermi surface and the superconducting state is formed by opening an "additional&#
M. A. McLaughlin, A. G. Lyne, D. R. Lorimer, A. Possenti
We have investigated the eclipse of the 23-ms pulsar J0737-3039A by its 2.8-s companion PSR J0737-3039B in the recently discovered double pulsar system using data taken with the Green Bank Telescope at 820 MHz. We find that the pulsed flux density at eclipse is strongly modulated with half the periodicity of the 2.8-s pulsar. The eclipse occurs earlier and i
Octavio Castanos, Ramon Lopez-Pena, Margarita A. Man'ko, Vladimir I. Man'ko
Some properties of Plebanski squeezing operator and squeezed states created with time-dependent quadratic in position and momentum Hamiltonians are reviewed. New type of tomography of quantum states called squeeze tomography is discussed.
Ruth E. Kastner
Tim Maudlin's argument for the inconsistency of Cramer's Transactional Interpretation (TI) of quantum theory has been considered in some detail by Joseph Berkovitz, who has provided a possible solution to this challenge at the cost of a significant empirical lacuna on the part of TI. The present paper proposes an alternative solution in which Maudlin
Jürgen Audretsch, Felix E. Klee, Thomas Konrad
We present a new scheme to detect and visualize oscillations of a single quantum system in real time. The scheme is based upon a sequence of very weak generalized measurements, distinguished by their low disturbance and low information gain. Accumulating the information from the single measurements by means of an appropriate Bayesian Estimator, the actual os
Recurrent fourth-order interference dips and peaks with a comb-like two-photon entangled state
quant-phAlessandro Zavatta, Silvia Viciani, Marco Bellini
We demonstrate full selective control over the constructive or destructive character of fourth-order recurring interferences in a modified version of a HOM interferometer using comb-like two-photon states. The comb spectral/temporal structure is obtained by inserting an etalon cavity in the signal path of an entangled photon pair obtained by pulsed spontaneo
Statistical properties of DNA sequences revisited: the role of inverse bilateral symmetry in bacterial chromosomes
q-bio.GNMarco V. Jose, Tzipe Govezensky, Juan R. Bobadilla
Herein it is shown that in order to study the statistical properties of DNA sequences in bacterial chromosomes it suffices to consider only one half of the chromosome because they are similar to its corresponding complementary sequence in the other half. This is due to the inverse bilateral symmetry of bacterial chromosomes. Contrary to the classical result
Cornelius Lanczos
The thesis developed by Cornelius Lanczos in his doctoral dissertation is that electrodynamics is a pure field theory which is hyperanalytic over the algebra of biquaternions. In this theory Maxwell's homogeneous equations correspond to a generalization of the Cauchy-Riemann regularity conditions to four complex variables, and electrons to singularities
J. Dunning-Davies
Recent references to the commonly accepted expression for the entropy of a black hole to questions concerning the constancy of some of the so-called 'universal constants of nature' are questioned, as is the validity of the said entropy expression.
D. Vartsky, I. Mor, M. B. Goldberg, I. Mardor
We have analyzed and compared the performance of two novel fast-neutron imaging methods with time-of-flight spectroscopy capability. Using MCNP and GEANT code simulations of neutron and charged-particle transport in the detectors, key parameters such as detection efficiency, the amount of energy deposited in the converter and the spatial resolution of both d
Dario Motta, Stefan Schoenert
The optical properties of the `bialkali' KCsSb and RbCsSb photomultiplier cathodes have been experimentally investigated in the visible range. The measurements carried out include the absolute reflectance at near-normal incidence, the polarization-dependent relative reflectance at various angles and the change in polarization upon reflection from the pho
Detectors for Time-of-Flight Fast-Neutron Radiography: 1. Neutron Counting Gas Detector
physics.ins-detV. Dangendorf, A. Breskin, R. Chechik, M. Goldberg
One of our two methods for fast-neutron imaging with spectrometric capability is presented here. It is a neutron-counting technique based on a hydrogenous neutron converter coupled to Gaseous Electron Multipliers (GEM). The principles of the detection techniques and the optimization of the converter, electron amplification and the readout are described. Eval
On the Probability distribution function of particle density at the edge of fusion devices
physics.plasm-phF. Sattin, N. Vianello, M. Valisa
The Probability Distribution Function (PDF) Pn(n) of the particle density at the edge of several magnetic fusion devices, including tokamaks, stellarators, and linear devices, is known to be strongly non-gaussian. In this paper we present experimental results from RFX Reversed Field Pinch [G. Rostagni, Fus. Eng. Design 25, 301 (1995)], confirming the univers
S. Takahara, M. Tohyama, P. Schuck
The ground states and excited states of the Lipkin model hamiltonian are calculated using a new theoretical approach which has been derived from an extended time-dependent Hartree-Fock theory known as the time-dependent density-matrix theory (TDDM). TDDM enables us to calculate correlated ground states, and its small amplitude limit (STDDM), which is a versi
V. D. Burkert, R. De Vita, S. Niccolai, the CLAS collaboration
We discuss the experimental program to search for baryon states with exotic flavor quantum numbers using CLAS at Jefferson Lab.
R. C. Runkle, A. E. Champagne, C. Angulo, C. Fox
We have measured the 14N(p,g)15O excitation function for energies in the range E_p = 155--524 keV. Fits of these data using R-matrix theory yield a value for the S-factor at zero energy of 1.64(17) keV b, which is significantly smaller than the result of a previous direct measurement. The corresponding reduction in the stellar reaction rate for 14N(p,g)15O h
Shahar Seifer, Victor Steinberg
By performing sound scattering measurements with a detector array consisting of 62 elements in a flow between two counter-rotating disks we obtain the energy and vorticity power spectra directly in both spatial and temporal domains. Fast accumulated statistics and large signal-to-noise ratio allow to get high quality data rather effectively and to test scali
W. Klonowski
Presented theory of feelings and emotions is based on Nonlinear Dynamics and Theory of Complex Systems. The most important assumption is that the brain may be considered to be composed of subsystems characterized by different characteristic time scales. The theory explains a possible role of feelings and emotions in cognition. We propose to call presented th
Georg A. Gottwald, Lorenz Kramer
We present a non-perturbative technique to study pulse dynamics in excitable media. The method is used to study propagation failure in one-dimensional and two-dimensional excitable media. In one-dimensional media we describe the behaviour of pulses and wave trains near the saddle node bifurcation, where propagation fails. The generalization of our method to
Gianne Derks, Georg A. Gottwald
The spectral problem associated with the linearization about solitary waves of spinor systems or optical coupled mode equations supporting gap solitons is formulated in terms of the Evans function, a complex analytic function whose zeros correspond to eigenvalues. These problems may exhibit oscillatory instabilities where eigenvalues detach from the edges of
Thomas H. Otway
Unusual features of water waves that Galileo described in a letter to Cardinal Orsini in 1616 are revisited from the perspectives of singular optics and geometric analysis.
Jason Fulman
Let W be either the number of descents or inversions of a permutation. Stein's method is applied to show that W satisfies a central limit theorem with error rate n^(-1/2). The construction of an exchangeable pair (W,W') used in Stein's method is non-trivial and uses a non-reversible Markov chain.
Mohammadreza Raoofi
We investigate the $L^p $ asymptotic behavior $(1\le p \le \infty)$ of a perturbation of a Lax or overcompressive type shock wave solution to a system of conservation law in one dimension. The system of the equations can be strictly parabolic, or have real viscosity matrix (partially parabolic, e.g., compressible Navier--Stokes equations or equations of Magn
Mario Listing
This paper presents conformal invariants for Riemannian manifolds of dimension greater than or equal to four whose vanishing is necessary for a Riemannian manifold to be conformally related to an Einstein space. One of the invariants is a modification of the Cotton tensor, the other is a $n$--dimensional version of the Bach tensor. In general both tensors ar
Lydia Delvaux, Alfons Van Daele, Shuanhong Wang
We put the known results on the antipode of a usual quasitriangular Hopf algebra into the framework of multiplier Hopf algebras. We illustrate with examples which can not be obtained using classical Hopf Algebras. The focus of the present paper lies on the class of the so-called group cograded multiplier Hopf algebras. By doing so, we bring the results of qu
Alfons Van Daele, Shuanhong Wang
Any finite-dimensional Hopf algebra has a left and a right integral. Conversely, Larsen and Sweedler showed that, if a finite-dimensional algebra with identity and a comultiplication with counit has a faithful left integral, it has to be a Hopf algebra. In this paper, we generalize this result to possibly infinite-dimensional algebras, with or without identi
Stefan Waldmann
In this review we discuss various aspects of representation theory in deformation quantization starting with a detailed introduction to the concepts of states as positive functionals and the GNS construction. But also Rieffel induction of representations as well as strong Morita equivalence, the Dirac monopole and the strong Picard groupoid are discussed.
Dror Bar-Natan
This is an overview article on finite type invariants, written for the Encyclopedia of Mathematical Physics
Marina Ramon Medrano, Norma G. Sanchez
We explicitly describe the last stages of black hole evaporation in the context of string theory : the combined study of Quantum Field Theory (QFT) and String Theory (ST) in curved backgrounds allows us to go further in the understanding of quantum gravity effects. The string ``analogue model''(or thermo-dynamical approach) is a well suited framework
Joseph Towe
A conventional graviton vertex operator is generated from the gauging of global supersymmetry. If the outgoing gravitino is replaced by a fermion-boson pair of like helicity, and if a new principle of equivalence associates supergravity with the introduction of color, then every quark flavor can be described as a gravitationally excited lepton. In this conte
E. A. Paschos, M. Sakuda, I. Schienbein, J. Y. Yu
We consider resonance production by neutrinos focusing on the dominant resonance $P_{33}$ at low energies with a detailed discussion of its form factors. The results are presented for free nucleon targets. The $Δ$ resonance is described by two form factors $C_3^V$ and $C_5^A$ and its differential cross sections are compared with experimental data. Further, w
Wolfgang Lucha, F. F. Schoberl
The spinless Salpeter equation represents the simplest and most straightforward generalization of the Schroedinger equation of standard nonrelativistic quantum theory towards the inclusion of relativistic kinematics. Moreover, it can be also regarded as a well-defined approximation to the Bethe-Salpeter formalism for descriptions of bound states in relativis
L. P. Csernai, A. Anderlik, Cs. Anderlik, V. K. Magas
Fluid dynamical calculations with QGP showed a softening of the directed flow while with hadronic matter this effect is absent. On the other hand, we indicated that a third flow component shows up in the reaction plane as an enhanced emission, which is orthogonal to the directed flow. This is not shadowed by the deflected projectile and target, and shows up
Petr Zavada
The spin structure of the system of quasifree fermions having total angular momentum $J=1/2$ is studied in a consistently covariant approach. Within this model the relations between the spin functions are obtained. Their particular cases are the sum rules Wanzura - Wilczek, Efremov - Leader - Teryaev, Burkhardt - Cottingham and also the expression for the Wa
Kingman Cheung
In this talk, I summarize the activities in the $e^- e^-$ session. The consensus is that if the next generation $e^+ e^-$ linear collider wants to include an $e^- e^-$ option, the planning has to include it as early as possible. By doing so the extra cost would be only a small fraction of the total, and of course the physics potential would be very rewarding