Research archive
arXiv papers from January 2005
The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.
Heron Caldas, C. W. Morais, A. L. Mota
In this paper, we study phase transitions in asymmetrical fermion superfluids. In this scenario, the candidates to form pair are particles with mismatched masses and chemical potentials. We derive an expression for the critical temperature in terms of the gap and masses (or chemical potentials) when the constraint of equal Fermi surfaces $m_a\mu_a = m_b\mu_b
D. S. Petrov, C. Salomon, G. V. Shlyapnikov
We give a brief overview of recent studies of weakly bound homonuclear molecules in ultracold two-component Fermi gases. It is emphasized that they represent novel composite bosons, which exhibit features of Fermi statistics at short intermolecular distances. In particular, Pauli exclusion principle for identical fermionic atoms provides a strong suppression
Bin Liu, J. Goree
The shear viscosity of a two-dimensional (2D) liquid was calculated using equilibrium molecular dynamics simulations with a Yukawa potential. The shear viscosity has a minimum, at a Coulomb coupling parameter of about 17, arising from the temperature dependence of the kinetic and potential contributions. Previous calculations of 2D viscosity were less extens
Ivan G. Avramidi
We review the construction of the Dirac operator and its properties in Riemannian geometry and show how the asymptotic expansion of the trace of the heat kernel determines the spectral invariants of the Dirac operator and its index. We also point out that the Einstein-Hilbert functional can be obtained as a linear combination of the first two spectral invari
David Prendergast, Jeffrey C. Grossman, Giulia Galli
In the last decade, computational studies of liquid water have mostly concentrated on ground state properties. However recent spectroscopic measurements have been used to infer the structure of water, and the interpretation of optical and x-ray spectra requires accurate theoretical models of excited electronic states, not only of the ground state. To this en
E. Ya. Sherman, Ali Najmaie, J. E. Sipe
We show that a pure spin current can be injected in quantum wells by the absorption of linearly polarized infrared radiation, leading to transitions between subbands. The magnitude and the direction of the spin current depend on the Dresselhaus and Rashba spin-orbit coupling constants and light frequency and, therefore, can be manipulated by changing the lig
- The formation and evolution of hydrogen-deficient post-AGB white dwarfs: the emerging chemical profile and the expectations for the PG1159-DB-DQ evolutionary connectionastro-ph
L. G. Althaus, A. M. Serenelli, J. A. Panei, A. H. Corsico
This paper is designed to explore the formation and evolution of hydrogen-deficient post-AGB white dwarfs. To this end, we compute the complete evolution of an initially 2.7 M_sun star from the zero-age main sequence through the thermally pulsing and mass-loss phases to the white dwarf stage. Particular attention is given to the chemical abundance changes du
Jiangping Hu
We show that electric field can induce spin polarization and dichroism effects in angle resolved photoemission spectroscopy (ARPES) in spin orbit coupling systems. The physical origin behind the effects essentially is the same as the spin Hall effect induced by the electric field. Since the ARPES experiments have both energy and momentum resolutions, the spi
C. Z. Waters, S. E. Zepf
We present new ultraviolet photometry of the jet in M87 obtained from HST WFPC2 imaging. We combine these ultraviolet data with previously published photometry for the knots of the jet in radio, optical, and X-ray, and fit three theoretical synchrotron models to the full data set. The synchrotron models consistently overpredict the flux in the ultraviolet wh
O. P. Vajk, M. Kenzelmann, J. W. Lynn, S. B. Kim
Hexagonal HoMnO$_{3}$ is a frustrated antiferromagnet (T$_{N}$=72 K) ferroelectric (T$_{C}$=875 K) in which these two order parameters are coupled. Our neutron measurements of the spin wave dispersion for the S=2 Mn$^{3+}$ on the layered triangular lattice are well described by a two-dimensional nearest-neighbor Heisenberg exchange J=2.44 meV, and an anisotr
Stefano Vidussi
The purpose of this paper is to present some results on the existence of homologous, nonisotopic symplectic or lagrangian surfaces embedded in a simply connected symplectic 4-dimensional manifold.
J. Phillips
The N = 1 superfield formalism in four-dimensions is well formulated and understood, yet there remain unsolved problems. In this thesis, superfield actions for free massless and massive higher spin superfield theories are formulated in four dimensions. The discussion of massless models is restricted to half integer superhelicity. These models describe multip
Pradeep Kiran Sarvepalli, Andreas Klappenecker
We construct nonbinary quantum codes from classical generalized Reed-Muller codes and derive the conditions under which these quantum codes can be punctured. We provide a partial answer to a question raised by Grassl, Beth and Roetteler on the existence of q-ary quantum MDS codes of length n with q\le n\le q^2-1.
Ralph Blumenhagen, Mirjam Cvetic, Paul Langacker, Gary Shiu
We provide a pedagogical introduction to a recently studied class of phenomenologically interesting string models, known as Intersecting D-Brane Models. The gauge fields of the Standard-Model are localized on D-branes wrapping certain compact cycles on an underlying geometry, whose intersections can give rise to chiral fermions. We address the basic issues a
P. A. Cassak, M. A. Shay, J. F. Drake
A catastrophe model for the onset of fast magnetic reconnection is presented that suggests why plasma systems with magnetic free energy remain apparently stable for long times and then suddenly release their energy. For a given set of plasma parameters there are generally two stable reconnection solutions: a slow (Sweet-Parker) solution and a fast (Alfv\'eni
- Clifford and Extensor Calculus and the Riemann and Ricci Extensor Fields in of Deformed Structuresmath.DG
Virginia V. Fernandez, Waldyr A. Rodrigues, Antonio M. Moya, Roldao da Rocha
Here (the last paper in a series of four) we end our presentation of the basics of a systematical approach to the differential geometry of a smooth manifold M (supporting a metric field g and a general connection del) which uses the geometric algebras of multivector and extensors (fields) developed in previous papers. The theory of the Riemann and Ricci fiel
David M. Bradley
The double zeta function was first studied by Euler in response to a letter from Goldbach in 1742. One of Euler's results for this function is a decomposition formula, which expresses the product of two values of the Riemann zeta function as a finite sum of double zeta values involving binomial coefficients. In this note, we establish a q-analog of Euler's d
Yuriy V Pershin, Carlo Piermarocchi
We analize theoretically the dynamics of N electrons localized in a semiconductor quantum ring under a train of phase-locked infrared laser pulses. The pulse sequence is designed to control the total angular momentum of the electrons. The quantum ring can be put in states characterized by strong currents. The local magnetic field created by these currents ca
V. V. Fernadez, A. M. Moya, W. A. Rodrigues
This paper (the seventh paper in a series of eight) continues the development of our theory of multivector and extensor calculus on smooth manifolds. Here we deal first with the concepts of ordinary Hodge coderivatives, duality identities, and Hodge coderivative identities. Then, we recall the concept of a Levi-Civita geometric structure and the concepts of
- Massive galaxies & EROs at z=1-3 in cosmological hydrodynamic simulations: near-IR propertiesastro-ph
Kentaro Nagamine, Renyue Cen, Lars Hernquist, Jeremiah P. Ostriker
Recent observations have revealed a population of red massive galaxies at high redshift which are challenging to explain in hierarchical galaxy formation models. We analyze this ``massive galaxy problem'' with two different types of hydrodynamic simulations -- Eulerian TVD and SPH -- of a concordance Lambda CDM universe. We consider two separate but connecte
A. P. Koperski, M. T. Koperski
This paper was withdrawn by arXiv admin due to authors' misrepresentation of identity/affiliation.
Martin White
As gravitational lensing measurements become increasingly precise, it becomes necessary to include ever higher order effects in the theoretical calculations. Here we show how the difference between the shear and the reduced shear manifest themselves in a number of commonly used measures of shear power. If we are to reap the science rewards of future, high pr
Duane A. Liedahl
We examine the effects of resonant Auger destruction in modifying the intensities and flux distributions of K-alpha spectra from iron L-shell ions. Applications include X-ray irradiated stellar winds in X-ray binaries and accretion disk atmospheres. Using detailed atomic models, we find that resonant Auger destruction is selective, in that only a subset of t
John Ellis, Keith A. Olive, Yudi Santoso, Vassilis C. Spanos
We compare updated predictions for the elastic scattering of supersymmetric neutralino dark matter with the improved experimental upper limit recently published by CDMS II. We take into account the possibility that the \pi-nucleon \Sigma term may be somewhat larger than was previously considered plausible, as may be supported by the masses of exotic baryons
Eylee Jung, D. K. Park
The absorption and emission problems of the brane-localized and bulk scalars are examined when the spacetime is a $(4+n)$-dimensional Reissner-Nordstr\"{o}m black hole. Making use of an appropriate analytic continuation, we compute the absorption and emission spectra in the full range of particle's energy. For the case of the brane-localized scalar the prese
- An Inflaton Mass Problem in String Inflation from Threshold Corrections to Volume Stabilizationhep-th
Liam McAllister
Inflationary models whose vacuum energy arises from a D-term are believed not to suffer from the supergravity eta problem of F-term inflation. That is, D-term models have the desirable property that the inflaton mass can naturally remain much smaller than the Hubble scale. We observe that this advantage is lost in models based on string compactifications who
Sophia A. Khan, Dominic J. Benford, David L. Clements, S. Harvey Moseley
We have resolved the ultraluminous infrared galaxy (ULIRG), IRAS 09111-1007, with the new 350 micron-optimised Second Generation Submillimeter High Angular Resolution Camera (SHARC II) and present the first submillimetre fluxes and images for the system. IRAS 09111-1007 comprises two interacting luminous infrared galaxies (LIRGs) with a projected nuclear sep
Zvi Bern, Lance J. Dixon, David A. Kosower
We present examples of on-shell recurrence relations for determining rational functions appearing in one-loop QCD amplitudes. In particular, we give relations for one-loop QCD amplitudes with all legs of positive helicity, or with one leg of negative helicity and the rest of positive helicity. Our recursion relations are similar to the tree-level ones descri
Hisham Sati
In this note we show that the Chern-Simons and the one-loop terms in the M-theory action can be written in terms of new characters involving the M-theory four-form and the string classes. This sheds a new light on the topological structure behind M-theory and suggests the construction of a theory of `higher' characteristic classes.
C. H. Li, G. Kioseoglou, O. M. J. van t Erve, M. E. Ware
We report electrical control of the spin polarization of InAs/GaAs self-assembled quantum dots (QDs) at room temperature. This is achieved by electrical injection of spin-polarized electrons from an Fe Schottky contact. The circular polarization of the QD electroluminescence shows that a 5% electron spin polarization is obtained in the InAs QDs at 300 K, whi
V. M. Shabaev, K. Pachucki, I. I. Tupitsyn, V. A. Yerokhin
The complete gauge-invariant set of the one-loop QED corrections to the parity-nonconserving 6s-7s amplitude in $^{133}$Cs is evaluated to all orders in $\alpha Z$ using a local version of the Dirac-Hartree-Fock potential. The calculations are peformed in both length and velocity gauges for the absorbed photon. The total binding QED correction is found to be
W. A. Rodrigues, V. V. Fernandez, A. M. Moya
This paper, sixth in a series of eight, uses the geometric calculus on manifolds developed in previous papers of the series to introduce through the concept of a metric extensor field g a metric structure for a smooth manifold M. The associated Christoffel operators, a notable decomposition of that object and the associated Levi-Civita connection field are g
A. M. Moya, V. V. Fernadez, W. A. Rodrigues
We give in this paper which is the fifth in a series of eight a theory of covariant derivatives of multivector and extensor fields based on the geometric calculus of an arbitrary smooth manifold M, and the notion of a connection extensor field defining a parallelism structure on M. Also we give a novel and intrinsic presentation (i.e., one that does not depe
A. M. Moya, V. V. Fernandez, W. A. Rodrigues
The objective of the present paper (the second in a series of four) is to give a theory of multivector and extensor fields on a smooth manifold M of arbitrary topology based on the powerful geometric algebra of multivectors and extensors. Our approach does not suffer the problems of earlier attempts which are restricted to vector manifolds. It is based on th
A. M. Moya, V. V. Fernandez, W. A. Rodrigues
This paper, the third in a series of eight introduces some of the basic concepts of the theory of extensors needed for our formulation of the differential geometry of smooth manifolds . Key notions such as the extension and generalization operators of a given linear operator (a (1,1)-extensor) acting on a real vector space V are introduced and studied in det
A. M. Moya, V. V. Fernadez, W. A. Rodrigues
In this paper, the second in a series of eight we continue our development of the basic tools of the multivector and extensor calculus which are used in our formulation of the differential geometry of smooth manifolds of arbitrary topology . We introduce metric and gauge extensors, pseudo-orthogonal metric extensors, gauge bases, tetrad bases and prove the r
A. M. Moya, V. V. Fernandez, W. A. Rodrigues
This is the first paper in a series of eight where in the first three we develop a systematic approach to the geometric algebras of multivectors and extensors, followed by five papers where those algebraic concepts are used in a novel presentation of several topics of the differential geometry of (smooth) manifolds of arbitrary global topology. A key tool fo
Emiliano Papa, Allan H. Macdonald
In this paper we introduce and study the correlation functions of a chiral one-dimensional electron model intended to qualitatively represent narrow Hall bars separated into left and right sections by a penetrable barrier. The model has two parameters representing respectively interactions between top and bottom edges of the Hall bar and interactions between
C. Markert
The resonance production of $\Delta$, K(892), $\Sigma$(1385), $\Lambda$(1520) and $\phi$ from elementary p+p and Au+Au collisions at $\sqrt{s_{\rm NN}} = $ 200 GeV from the STAR experiment at RHIC is presented. Yields and spectra are discussed in terms of chemical and thermal freeze-out conditions. Thermal models do not describe sufficiently the yields of th
V. Varela
We consider the extension of the Majumdar-type class of static solutions for the Einstein-Maxwell equations, proposed by Ida to include charged perfect fluid sources. We impose the equation of state $\rho+3p=0$ and discuss spherically symmetric solutions for the linear potential equation satisfied by the metric. In this particular case the fluid charge densi
Huan Z. Huang
We present experimental features of identified particle production from nucleus-nucleus collisions at RHIC. These features reflect hadronization from a deconfined partonic matter whose particle formation scheme is distinctly different from fragmentation phenomenology in elementary collisions. Multi-parton dynamics, such as quark coalescences or recombination
P. Benes, Amand Faessler, S. Kovalenko, F. Simkovic
We study possible contribution of the Majorana neutrino mass eigenstate $\nu_h$ dominated by a sterile neutrino component to neutrinoless double beta ($0\nu\beta\beta$) decay. From the current experimental lower bound on the $0\nu\beta\beta$-decay half-life of $^{76}$Ge we derive stringent constraints on the $\nu_h-\nu_e$ mixing in a wide region of the value
Neil D. Christensen, Robert Shrock
We point out that if quark and lepton masses arise dynamically, then in a wide class of theories the corresponding running masses $m_{f_j}(p)$ exhibit the power-law decay $m_{f_j}(p) \propto \Lambda_j^2/p^2$ for Euclidean momenta $p >> \Lambda_j$, where $f_j$ is a fermion of generation $j$, and $\Lambda_j$ is the maximal scale relevant for the origin of $m_{
- A search for CP violation and a measurement of the relative branching fraction in D+ -> KKpi decayshep-ex
B. Aubert
We report on a search for the CP asymmetry in the singly Cabibbo-suppressed decays D+ -> KKpi and in the resonant decays D+ -> phipi and D+ -> KstarK based on a data sample of 79.9 fb^-1 recorded by the BABAR detector. We use the Cabibbo-favored Ds -> KKpi branching fraction as normalization in the measurements to reduce systematic uncertainties. The CP asym
Ozgur Delice
This paper has been withdrawn by the author, See J.Krishna Rao, J. Phys. A: Gen. Phys., 4, 17 (1971) for radiating Levi-Civita metric.
T. W. B. Muxlow, A. M. S. Richards, S. T. Garrington, P. N. Wilkinson
Eighteen days of MERLIN data and 42 hours of A-array VLA data at 1.4 GHz have been combined to image a 10-arcmin field centred on the Hubble Deep and Flanking Fields (HDF and HFF). A complete sample of 92 radio sources with 1.4-GHz flux densities above 40 microJy has been imaged using MERLIN+VLA. The images are amongst the most sensitive yet made at 1.4 GHz,
Narutaka Ozawa
Let K be a fine hyperbolic graph and G be a group acting on K with finite quotient. We prove that G is exact provided that all vertex stabilizers are exact. In particular, a relatively hyperbolic group is exact if all its peripheral groups are exact. We prove this by showing that the group G acts amenably on a compact topological space. We include some appli
B. Abbott, P. Baringer, T. Bolton, Z. Greenwood
The D0 experiment at Fermilab's Tevatron will record several petabytes of data over the next five years in pursuing the goals of understanding nature and searching for the origin of mass. Computing resources required to analyze these data far exceed capabilities of any one institution. Moreover, the widely scattered geographical distribution of D0 collaborat
D. Bashkirov, G. Sardanashvily
Quantization of gravitation theory as gauge theory of general covariant transformations in the framework of Batalin-Vilkoviski (BV) formalism is considered. Its gauge-fixed Lagrangian is constructed.
- Near degeneracy and pseudo Jahn-Teller effects in mixed-valence ladders: the phase transition in NaV$_2$O$_5$cond-mat.str-el
L. Hozoi, S. Nishimoto, A. Yamasaki
We analyze the electronic structure of a mixed-valence ladder system. We find that structural anisotropy and complex electron correlations lead to on-rung charge localization and insulating character. Charge fluctuations within the rung of the ladder interact strongly to the lattice degrees of freedom, which gives rise to large pseudo Jahn--Teller effects. T
- A comprehensive Fourier (k-) space design approach for controllable single and multiple photon localization statesphysics.optics
Subhasish Chakraborty1, Michael C. Parker2, Robert J. Mears3, David G Hasko1
A Fourier-space based design approach for the systematic control of single and multiple photon localization states in a 1D lattice is presented. Resultant lattices are aperiodic in nature, such that lattice periodicity is not a useful optimization parameter to achieve novel field localization characteristics. Instead, direct control of field localization com
L. Biferale, G. Boffetta, A. Celani, B. J. Devenish
We present a detailed investigation of the particle pair separation process in homogeneous isotropic turbulence. We use data from direct numerical simulations up to Taylor's Reynolds number 280 following the evolution of about two million passive tracers advected by the flow over a time span of about three decades. We present data for both the separation dis
Andrea Dainese
With the acceleration of lead nuclei in the LHC, heavy-ion physics will enter a new energy domain. One of the main novelties introduced by the 30-fold energy-jump from RHIC to the LHC is the abundant heavy-quark production. After discussing a few examples of physics issues that can be addressed using heavy quarks, we present a selection of results on the exp
Andrea Dainese
D-meson suppression in Pb-Pb collisions at the LHC due to charm quark in-medium energy loss is estimated within a model that describes the available quenching measurements at RHIC. The result is compared to that previously published by the author. The expected sensitivity of the ALICE experiment for studying charm energy loss via fully-reconstructed D^0-meso
Andrew Hone
The Somos 5 sequences are a family of sequences defined by a fifth order bilinear recurrence relation with constant coefficients. For particular choices of coefficients and initial data, integer sequences arise. By making the connection with a second order nonlinear mapping with a first integral, we prove that the two subsequences of odd/even index terms eac
- Blind search for the real sample: Application to the origin of ultra-high energy cosmic raysastro-ph
Boris E. Stern, Juri Poutanen
We suggest a method for statistical tests which does not suffer from a posteriori manipulations with tested samples (e.g. cuts optimization) and does not require a somewhat obscure procedure of the penalty estimate. The idea of the method is to hide the real sample (before it has been studied) among a large number of artificial samples, drawn from a random d
Stefan Antusch, Joern Kersten, Manfred Lindner, Michael Ratz
We systematically analyze quantum corrections in see-saw scenarios, including effects from above the see-saw scales. We derive approximate renormalization group equations for neutrino masses, lepton mixings and CP phases, yielding an analytic understanding and a simple estimate of the size of the effects. Even for hierarchical masses, they often exceed the p
R. Narayanan, H. Neuberger
It is possible to numerically solve QCD in the planar limit using standard numerical techniques on existing computer clusters. The basic ideas behind the computational strategy an recent numerical results in the fermionic sector of large N QCD are reviewed.
Javier Aramayona
We give a new proof that the completion of the Weil-Petersson metric on Teichm\"uller space is Gromov-hyperbolic if the surface is a five-times punctured sphere or a twice-punctured torus. Our methods make use of the synthetic geometry of the Weil-Petersson metric.
A. Gehrmann--De Ridder, T. Gehrmann, E. W. N. Glover
The computation of exclusive QCD jet observables at higher orders requires a method for the subtraction of infrared singular configurations arising from multiple radiation of real partons. One commonly used method at next-to-leading order (NLO) is based on the antenna factorization of colour-ordered matrix elements, and uses antenna functions to subtract the
A. M. Mel'nik
The spiral pattern of the Galaxy identified by analyzing the kinematics of young stars within 3 kpc of the Sun is Fourier decomposed into spiral harmonics. The spiral pattern of the Galaxy is shown to be representable as a superposition of trailing and leading waves with interarm distances of 1.8(+/-0.4) kpc and 4(+/-2) kpc, respectively. Shock waves are pro
T. Kawahara
On the basis of the relativistic symmetry of Minkowski space, we derive a Lorentz invariant equation for a spread electron. This equation slightly differs from the Dirac equation and includes additional terms originating from the spread of an electron. Further, we calculate the anomalous magnetic moment based on these terms. These calculations do not include
K. M. Vanlandingham, G. J. Schwarz, S. N. Shore, S. Starrfield
We present a new analysis of existing optical and ultraviolet spectra of the ONeMg nova V1974 Cygni 1992. Using these data and the photoionization code Cloudy, we have determined the physical parameters and elemental abundances for this nova. Many of the previous studies of this nova have made use of incorrect analyses and hence a new study was required. Our
Peter M. Kruse, Andre Naujoks, Dietmar Roesner, Manuela Kunze
This paper presents an approach to enhance search engines with information about word senses available in WordNet. The approach exploits information about the conceptual relations within the lexical-semantic net. In the wrapper for search engines presented, WordNet information is used to specify user's request or to classify the results of a publicly availab
Hacen Dib
Using Bessel-Muirhead system, we can express the K-bessel function defined on a Jordan algebra as linear combination of the J-solutions. We determine explicitly the coefficients when the rank of this Jordan algebra is three after a reduction to the rank two. The main tools are some algebraic identities developed for the occasion.
Shi-Yuan Li
In relativistic heavy ion collisions, the cross section of heavy hadron production via the combination of a heavy quark with a light one from the quark-gluon matter can be factorized. It is the convolution of twist-4 combination matrix elements, the parameters corresponding to the parton distributions of the quark-gluon matter, as well as the hard partonic c
N. V. Kharchenko, A. E. Piskunov, S. Röser, E. Schilbach
We present a catalogue of astrophysical data of 520 Galactic open clusters. These are the clusters, for which at least three most probable members (18 on average) could be identified in the ASCC-2.5, a catalogue of stars based on the Tycho-2 observations from the Hipparcos mission. We applied homogeneous methods and algorithms to determine angular sizes of c
J. L. Gavilano, E. Felder, D. Rau, H. R. Ott
We report the results of low-temperature measurements of the specific heat Cp(T), ac susceptibility chi(T) and 23Na nuclear magnetic resonance NMR of Na2V3O7. At liquid He temperatures Cp(T)/T exhibits broad field-dependent maxima, which shift to higher temperatures upon increasing the applied magnetic field H. Below 1.5 K the ac magnetic susceptibility chi(
M. Encinosa
An efficient procedure for generating Gram-Schmidt states on a toroidal surface $T^2$ is presented. As an application of the method, low-lying eigenvalues and wave functions for an electron on $T^2$ subjected to a constant magnetic field are determined.
John L. Spiesberger
Locating where transient signals travel between a source and receiver requires a final step that is needed after using a theory of diffraction such as the integral theorem of Helmholtz and Kirchhoff. Introduced here, the final step accounts for interference between adjacent apertures on a phase screen by adaptively adjusting their phase and amplitude, yieldi
Remo Garattini
We compute the graviton one loop contribution to a classical energy in a traversable wormhole background. Such a contribution is evaluated by means of a variational approach with Gaussian trial wave functionals. A zeta function regularization is involved to handle with divergences. A renormalization procedure is introduced and the finite one loop energy is c
Mei-Rong Li, Karyn Le Hur, Walter Hofstetter
We show that the Bose-Fermi Kondo model (BFKM), which may find applicability both to certain dissipative mesoscopic qubit devices and to heavy fermion systems described by the Kondo lattice model, can be mapped exactly onto the Caldeira-Leggett model. This mapping requires an ohmic bosonic bath and an Ising-type coupling between the latter and the impurity s
Steven D. Doty, Sheila E. Everett, Yancy L. Shirley, Neal J. Evans
A series of self-consistent, three-dimensional continuum radiative transfer models are constructed of the pre-protostellar core L1544, with the results compared with existing SCUBA and ISO data. The source is well-fit by a prolate spheroid, having an ellipsoidal power-law density distribution of index m ~ 2 (1.75 < m < 2.25) in to at least r ~ 1600AU. For r<
Prabodh Shukla
Coarsening and persistence of Ising spins on a ladder is examined under voter dynamics. The density of domain walls decreases algebraically with time as $t^-{1/2}$ for sequential as well as parallel dynamics. The persistence probability decreases as $t^{-\theta_{s}}$ under sequential dynamics, and as $t^{-\theta_{p}}$ under parallel dynamics where $\theta_{p
- Third-order Coulomb corrections to the S-wave Green function, energy levels and wave functions at the originhep-ph
M. Beneke, Y. Kiyo, K. Schuller
We obtain analytic expressions for the third-order corrections due to the strong interaction Coulomb potential to the S-wave Green function, energy levels and wave functions at the origin for arbitrary principal quantum number n. Together with the known non-Coulomb correction this results in the complete spectrum of S-states up to order alpha_s^5. The numeri
A. V. Kotikov, V. N. Velizhanin
We derive the analytic continuation of the Mellin moments of deep inelastic structure functions at the next-to-next-to-leading order accuracy.
Katherine Freese
The Cardassian universe is a proposed modification to the Friedmann equation in which the universe is flat, matter dominated, and accelerating. In the ordinary Friedmann equation, the right hand side is a linear function of the energy density, $H^2 \sim \rho$. Here, instead, the right hand side of the Friedmann equation is a different function of the energy
Spiros Cotsakis, Ifigeneia Klaoudatou
We review recent work and present new examples about the character of singularities in globally and regularly hyperbolic, isotropic universes. These include recent singular relativistic models, tachyonic and phantom universes as well as inflationary cosmologies.
H. W. Schumacher
A ringing free bit addressing scheme for magnetic memories like MRAM (magnetic random access memory) is proposed. As in standard MRAM addressing schemes the switching of a selected cell is obtained by the combination of two half-select field pulses. Numerical solutions of a single spin model of an MRAM cell show that the pulse parameters can be chosen such t
A. Brandenburg, L. Covi, K. Hamaguchi, L. Roszkowski
The axino and the gravitino are well-motivated candidates for the lightest supersymmetric particle (LSP) and also for cold dark matter in the Universe. Assuming that a charged slepton is the next-to-lightest supersymmetric particle (NLSP), we show how the NLSP decays can be used to probe the axino LSP scenario in hadronic axion models as well as the gravitin
P. Gawronski, P. Gronek, K. Kulakowski
The Heider balance is a state of a group of people with established mutual relations between them. These relations, friendly or hostile, can be measured in the Bogardus scale of the social distance. In previous works on the Heider balance, these relations have been described with integers 0 and $\pm1$. Recently we have proposed real numbers instead. Also, di
D. Vogt, P. S. Letelier
New families of exact general relativistic thick disks are constructed using the ``displace, cut, fill and reflect'' method. A class of functions used to ``fill'' the disks is derived imposing conditions on the first and second derivatives to generate physically acceptable disks. The analysis of the function's curvature further restrict the ranges of the fre
J. R. Cudell, A. Lengyel, E. Martynov, O. V. Selyugin
We review the evidence for the presence of a hard singularity in soft forward amplitudes, and give an estimate of its trajectory and couplings.
Alberto Calabri, Ciro Ciliberto, Margarida Mendes Lopes
Minimal algebraic surfaces of general type with the smallest possible invariants have geometric genus zero and K^2=1 and are usually called "numerical Godeaux surfaces". Although they have been studied by several authors, their complete classification is not known. In this paper we classify numerical Godeaux surfaces with an involution, i.e. with an automorp
Tom Claeys, Arno B. J. Kuijlaars
We study unitary random matrix ensembles in the critical case where the limiting mean eigenvalue density vanishes quadratically at an interior point of the support. We establish universality of the limits of the eigenvalue correlation kernel at such a critical point in a double scaling limit. The limiting kernels are constructed out of functions associated w
B. Rothenstein, A. De Sabata
Transformation equations for physical quantities that characterize plane electromagnetic wave propagation in transparent optical media are presented. The Doppler effect, and measurements performed by an observer moving with the wave are also considered. The results, not mentioned in introductory Physics textbooks, are simple to derive and could be used in un
M. A. G. Alvarez, N. Alamanos, L. C. Chamon, M. S. Hussein
Elastic scattering angular distributions for systems with reduced mass between 3 and 34 and energies varying between 25 and 120 MeV/nucleon were analyzed. The stable $^4$He, its exotic partner $^6$He, and the weakly bound $^{6,7}$Li nuclei were included as projectiles in the systematics. Optical model data analyzes were performed with an adjustable factor of
Kinjal Banerjee, Ghanashyam Date
One of the qualitatively distinct and robust implication of Loop Quantum Gravity (LQG) is the underlying discrete structure. In the cosmological context elucidated by Loop Quantum Cosmology (LQC), this is manifested by the Hamiltonian constraint equation being a (partial) difference equation. One obtains an effective Hamiltonian framework by making the conti
I. Zychor, V. Koptev, M. Buescher, A. Dzyuba
The reaction pp->pK+Y has been studied with the ANKE spectrometer at COSY-Juelich in order to investigate heavy hyperon production. The missing mass spectra MM(pK+) have been analyzed and compared with Monte Carlo simulations. Indications for a hyperon resonance Y0*(1480) have been found.
S. V. Jeffers, A. Collier Cameron, J. R. Barnes, J. P. Aufdenberg
We have used spectrophotometric data from the Hubble Space Telescope to eclipse-map the primary component of the RS CVn binary SV Cam over 9 HST orbits. We find from these observations and the HIPPARCOS parallax that the surface flux in the eclipsed low-latitude region of the primary is about 30% lower than computed from a PHOENIX model atmosphere at the eff
- On the Light Curve and Spectrum of SN 2003dh Separated from the Optical Afterglow of GRB 030329astro-ph
J. Deng, N. Tominaga, P. A. Mazzali, K. Maeda
The net optical light curves and spectra of the supernova (SN) 2003dh are obtained from the published spectra of GRB 030329, covering about 6 days before SN maximum to about 60 days after. The bulk of the U-band flux is subtracted from the observed spectra using early-time afterglow templates, because strong line blanketing greatly depresses the UV and U-ban
- Is Arcturus a well-understood K giant? Test of model atmospheres and potential companion detection by near-infrared interferometryastro-ph
T. Verhoelst, P. J. Bordé, G. Perrin, L. Decin
We present near-IR interferometric measurements of the K1.5 giant Arcturus (alpha Bootis), obtained at the IOTA interferometer with the FLUOR instrument, in four narrow filters with central wavelengths ranging from 2.03 to 2.39 micron. These observations were expected to allow us to quantify the wavelength dependence of the diameter of a typical K giant. The
Ye. S. Avotina, Yu. A. Kolesnichenko, A. N. Omelyanchouk, A. F. Otte
The oscillatory voltage dependence of the conductance of a quantum point contact in the presence of a single point-like defect has been analyzed theoretically. Such signals are detectable and may be exploited to obtain information on defect positions below a metal surface. Both tunnel junctions and ballistic contacts of adiabatic shape have been considered.
- On the dependence of third- and fourth-order moments on stability in the turbulent boundary layerphysics.ao-ph
Alberto Maurizi
In this short review it is suggested that the relationship between third- and fourth-order moments of turbulence in the atmospheric boundary layer depends on stability. This can explain some differences among datasets, and provides a key point for modelling improvement.
M. A. Serrano, M. Boguna
The configuration model is one of the most successful models for generating uncorrelated random networks. We analyze its behavior when the expected degree sequence follows a power law with exponent smaller than two. In this situation, the resulting network can be viewed as a weighted network with non trivial correlations between strength and degree. Our resu
- Vibrational excitation of diatomic molecular ions in strong-field ionization of diatomic moleculesphysics.atom-ph
Thomas Kim Kjeldsen, Lars Bojer Madsen
A model based on the strong-field and Born-Oppenheimer approximations qualitatively describes the distribution over vibrational states formed in a diatomic molecular ion following ionization of the neutral molecule by intense laser pulses. Good agreement is found with a recent experiment [X. Urbain et al., Phys. Rev. Lett. 92, 163004 (2004)]. In particular,
Y. L. Loh, V. Tripathi, M. Turlakov
We study the Ambegaokar-Eckern-Sch\"{o}n (AES) model for a regular array of metallic grains coupled by tunnel junctions of conductance $g$ and calculate both paramagnetic and diamagnetic terms in the Kubo formula for the conductivity. We find analytically, and confirm by numerical path integral Monte Carlo methods, that for $0<g<4$ the conductivity obeys an
Christopher J. Fewster
Quantum fields are known to violate all the pointwise energy conditions of classical general relativity. We review the subject of quantum energy inequalities: lower bounds satisfied by weighted averages of the stress-energy tensor, which may be regarded as the vestiges of the classical energy conditions after quantisation. Contact is also made with thermodyn
E. J. Copeland, A. Rajantie
We investigate the end of the inflationary period in the recently proposed scenario of locked inflation, and consider various constraints arising from density perturbations, loop corrections, parametric resonance and defect formation. We show that in a scenario where there is one long period of locked inflation, it is not possible to satisfy all of these con
M. A. Cakir, S. Mutlu, L. Solmaz
We present a through discussion of motivations for and phenomenological issues in supersymmetric models with minimal matter content and non-holomorphic soft-breaking terms. Using the unification of the gauge couplings and assuming SUSY is broken with non-standard soft terms, we provide semi-analytic solutions of the RGEs for low and high choices of tan\beta