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October 2004 arXiv papers — page 3

Showing 201–300 of 4,138 papers

  1. S. I. Ipatov, J. C. Mather

    We integrated the orbital evolution of 30,000 Jupiter-family comets, 1300 resonant asteroids, and 7000 asteroidal, trans-Neptunian, and cometary dust particles. For initial orbital elements of bodies close to those of Comets 2P, 10P, 44P, and 113P, a few objects got Earth-crossing orbits with semi-major axes $a$$<$2 AU and moved in such orbits for more than

  2. S. I. Ipatov, J. C. Mather

    The orbital evolution of Jupiter-family comets (JFCs), resonant asteroids, and asteroidal, trans-Neptunian, and cometary dust particles under the gravitational influence of planets was integrated. For dust particles we also considered radiation pressure, Poynting-Robertson drag, and solar wind drag. The probability of a collision of one former JFC with a ter

  3. Benjamin F. Williams, Michael R. Garcia, Albert K. H. Kong, Frank A. Primini

    We have obtained snapshot images of an X-ray nova in M31 from Chandra ACIS-I and the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The Chandra position of the X-ray nova was R.A.=00:44:06.68 +/- 1.74&#34;, Dec.=+41:12:20.0 +/- 2.31&#34;. A follow-up HST observation 24 days later revealed a source at R.A.=00:44:06.81, Dec.=+41:12:24.0 that w

  4. L. Sbordone

    We present detailed Chemical abundances for 12 stars in the Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph) and 3 in the Canis Mayor Overdensity (CMa), based on UVES spectra. Sgr dSph stars present high metallicity ([Fe/H] between -1 and 0) low [alpha/Fe] ratios, overabundant La, Ce and Nd, underabundant Na, Al,Ni and Zn. Zn underabundance in particular is in

  5. S. Blais-Ouellette, P. Amram, C. Carignan, R. Swaters

    High resolution Fabry-Perot data of six spiral galaxies are presented. Those data extend the previous sample of spiral galaxies studied with high resolution 3D spectroscopy to earlier morphological types. All the galaxies in the sample have available HI data at 21 cm from the VLA or Westerbork. Velocity fields are analyzed and Halpha rotation curves are comp

  6. Lorenzo Monaco

    We present preliminary iron abundances and $α$ element (Ca, Mg) abundance ratios for a sample of 22 Red Giant Branch (RGB) Stars in the Sagittarius dwarf spheroidal galaxy (Sgr), selected near the RGB-Tip. The sample is representative of the Sgr dominant population. The mean iron abundance is [Fe/H]=-0.49. The $α$ element abundance ratios are slightly subsol

  7. Christopher H. De Vries, Philip C. Myers

    We present a study of analytic models of starless cores whose line profiles have ``infall asymmetry,&#39;&#39; or blue-skewed shapes indicative of contracting motions. We compare the ability of two types of analytical radiative transfer models to reproduce the line profiles and infall speeds of centrally condensed starless cores whose infall speeds are spati

  8. T. S. Boyajian, T. D. Beaulieu, D. R. Gies, E. Grundstrom

    We present results from a radial velocity study of two runaway O-type stars, HD 14633 (ON8.5 V) and HD 15137 (O9.5 III(n)). We find that HD 14633 is a single-lined spectroscopic binary with an orbital period of 15.4083 days. The second target HD 15137 is a radial velocity variable and a possible single-lined spectroscopic binary with a period close to 1 mont

  9. Carlos De Breuck

    The Atacama Large Millimeter Array (ALMA) consists of 64 antennas of 12m diameter that will initially observe in 4 frequency bands between 84 and 720 GHz with spatial resolutions down to 0.01&#34; and velocity resolutions as fine as 0.05 km/s. These technical requirements are based on three primary science goals. We illustrate two of these requirements: (i)

  10. Sivakumar G. Manickam

    We perform stability analysis of an accretion disc around a stellar mass black hole. The cooling of the accretion flow due to bremsstrahlung and synchrotron radiation processes are considered. The solutions with shock are perturbed at the shock location and the radial dependence of perturbation is obtained by solving the equations numerically using fourth-or

  11. Xu Kong

    This is the fourth paper in a series studying star formation rates, stellar components, metallicities, and star formation histories of a blue compact galaxy (BCG) sample. Using Ha, [OII]3727, IR, radio (1.4GHz) luminosities and neutral hydrogen gas masses, we estimated star formation rates(SFR) and gas depletion timescales of 72 star-forming BCGs. The SFRs o

  12. D. S. Gorbunov, S. V. Troitsky

    We consider various classes of persistent extragalactic astrophysical sources which have been suggested in literature as possible emitters of ultra-high-energy cosmic rays (UHECR). We compare the strength of the claimed correlations by a uniform procedure for all classes of sources by making use of the AGASA, Yakutsk and HiRes stereo data. BL Lac type object

  13. A. Just, J. Penarrubia

    We investigate the effect of a density gradient on Chandrasekhar&#39;s dynamical friction formula based on the method of 2-body encounters in the local approximation. We apply these generalizations to the orbit evolution of satellite galaxies in Dark Matter haloes. We find from the analysis that the main influence occurs through a position-dependent maximum

  14. M. Risse, P. Homola, R. Engel, D. Gora

    The longitudinal profile of the 320 EeV event observed by the Fly&#39;s Eye experiment is analysed. A method of testing the hypothesis of a specific primary particle type is described. Results for different particle types are summarized. For hadronic primaries between proton and iron nuclei, the discrepancy between observed and simulated profiles is in the r

  15. John C. Hodge

    The changing universe model (CUM) describes galaxy parameter relationships (SESAPS &#39;03, session EB 2). The CUM must be successfully applied to cosmological scale observations to be considered a cosmological model. A major component of current cosmological models is the Hubble constant $H_\mathrm{o}$. An equation is derived using the CUM model relating re

  16. Tim J Harries

    Spectropolarimetry is a photon-hungry technique that will reach fruition in the 8-m telescope age. Here I summarize some of the stellar spectropolarimetric research that my collaborators and I have undertaken, with particular emphasis on the circumstellar environment of massive stars, symbiotic binaries, and star formation.

  17. T. D. Kinman, A. Bragaglia, C. Cacciari, A. Buzzoni

    We have used RR Lyrae and Blue HB stars as tracers of the old Galactic halo, in order to study the halo structure and the galactic rotation as a function of height above the plane. Our sample includes 40 RR Lyrae and 80 BHB stars that are about 2 to 15 kpc above the plane, in a roughly 250 sq. deg. area around the North Galactic Pole (NGP). We use proper mot

  18. D. Heck

    Different interaction models treating hadronic collisions below E_lab < 100 GeV in air shower simulations are compared within the frame of the CORSIKA program. Their behaviour is studied in isolated collisions of protons or pions with light-mass targets in comparison with experimental data. It is discussed how model properties influence air-shower parameters

  19. Kazuya Saigo, Tomoaki Matsumoto, Masayuki Umemura

    We explore the possibility for the formation of Population III binaries. The collapse of a rotating cylinder is simulated with a three-dimensional, high-resolution nested grid, assuming the thermal history of primordial gas. The simulations are done with dimensionless units, and the results are applicable to low-mass as well as massive systems by scaling wit

  20. J. L. Halbwachs, M. Mayor, S. Udry

    A sample of spectroscopic binaries and a sample of single planetary systems, both having main-sequence solar-type primary components, are selected in order to compare their eccentricities. The positions of the objects in the (P.(1-e^2)^(3/2), e) plane is used to determine parts in the period-eccentricity diagram that are not affected by tidal circularization

  21. P. Hultzsch, D. Sauer, A. W. A. Pauldrach, T. Hoffmann

    Many aspects of the explosion mechanism of Type Ia supernovae (SN Ia) still remain unclear -- causing uncertainties in the derived cosmological parameters. Realistic models of the generation and transport of radiation in the ejecta are required which link theoretical explosion models to observations. We aim to construct theoretical spectra and light curves f

  22. A. Noels, J. Montalban, C. Maceroni

    We discuss the internal structure of stars in the mass range 1.5 to 4 M_sun from the PMS to the subgiant phase with a particular emphasis on the convective core and the convective superficial layers. Different physical aspects are considered such as overshooting, treatment of convection, microscopic diffusion and rotation. Their influence on the internal str

  23. A. Giesecke, U. Ziegler, G. Ruediger

    The equations for fully compressible rotating magnetoconvection are numerically solved in a Cartesian box assuming conditions roughly suitable for the geodynamo. The mean electromotive force describing the generation of mean magnetic flux by convective turbulence in the rotating fluid is directly calculated from the simulations, and the corresponding alpha-c

  24. Ryo Yamazaki, Kunihito Ioka, Takashi Nakamura, Kenji Toma

    We propose a possible unified model of short and long gamma-ray bursts (GRBs), X-ray rich GRBs, and X-ray flashes. The jet of a GRB is assumed to consist of multiple sub-jets or sub-shells (i.e., an inhomogeneous jet model). The multiplicity of the sub-jets along a line of sight n_s is an important parameter. If n_s is large (>> 1) the event looks like a lon

  25. Yuefang Wu, Yue Wei, Ming Zhao, Yong Shi

    A statistical study of the properties of molecular outflows is performed based on an up-to-date sample. 391 outflows were identified in published articles or preprints before February 28, 2003. The parameters of position, morphology, mass, energy, outflow dynamics and central source luminosity are presented for each outflow source. Outflow lobe polarity is k

  26. A. Palacios, C. Charbonnel, S. Talon, L. Siess

    Red giant stars, both in the field and in globular clusters, present abundance anomalies that can not be explained by standard stellar evolution models. Some of these peculiarities clearly point towards the existence of extra-mixing processes at play inside the stars, the nature of which remains unclear. We present new results of the evolution of a typical g

  27. P. A. Woudt, A. P. Fairall, R. C. Kraan-Korteweg, J. Lucey

    Deep J, H and Ks photometry of the low Galactic latitude Norma cluster has been obtained with the 1.4-m Infrared Survey Facility (IRSF) and with SOFI on the NTT. Together with spectroscopy taken at the Anglo-Australian Observatory using 2dF, the near-infrared Fundamental Plane of the Norma cluster will be used to determine the distance to this cluster and to

  28. H. Kang, T. W. Jones

    We have calculated the evolution of cosmic ray (CR) modified astrophysical shocks for a wide range of shock Mach numbers and shock speeds through numerical simulations of diffusive shock acceleration (DSA) in 1D quasi- parallel plane shocks. The simulations include thermal leakage injection of seed CRs, as well as pre-existing, upstream CR populations. Bohm-

  29. H. Hernandez-Toledo, V. Avila-Reese, C. J. Conselice, I. Puerari

    We present a structural analysis of nearby galaxies in spiral-spiral pairs in optical BVRI bands and compare with the structures of isolated spiral galaxies and galaxies in ongoing mergers. We use these comparisons to determine how galaxy structure changes during galaxy interactions and mergers. We analyze light concentration (C), asymmetry (A), and clumpine

  30. P. E. Hardee, R. C. Walker, J. L. Gomez

    The predicted spatial development of helical structures along an expanding jet are used to model observed structures and motions in the 3C 120 jet. Proper motions of helical components associated with the pattern and of other components that move through the pattern provide estimates of flow and helical pattern speeds. Theoretical modeling allows determinati

  31. Stefano Profumo, Kris Sigurdson, Piero Ullio, Marc Kamionkowski

    We show that charged-particles decaying in the early Universe can induce a scale-dependent or `running&#39; spectral index in the small-scale linear and nonlinear matter power spectrum and discuss examples of this effect in minimal supersymmetric models in which the lightest neutralino is a viable cold-dark-matter candidate. We find configurations in which t

  32. O. G. Semyonov

    Luminisity distances to the high-redshift Ia supernovas measured by the Supernova Cosmology Project team with the relativistic correction factors for redshift and time dilation led to the sensational conclusion about acceleration of universe expansion. The effect of relativistic aberration of high-redshift sources requires an additional correcting factor for

  33. Simon Portegies Zwart

    Young star clusters are often born with such high stellar densities that stellar collisions play an important role in their further evolution. In such environments the same star may participate in several tens to hundreds of collisions ultimately leading to the collapse of the star to a black hole of intermediate mass. At later time the black hole may acquir

  34. A. C. S. Readhead, S. T. Myers, T. J. Pearson, J. L. Sievers

    Polarization observations of the cosmic microwave background with the Cosmic Background Imager from September 2002 to May 2004 provide a significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectr

  35. R. R. Gal, L. M. Lubin, G. K. Squires

    The Cl 1604 supercluster at z~0.9 is known to contain at least four distinct member clusters, separated in both projection and redshift. In this paper we present deep, multicolor wide-field imaging of a region spanning ~45&#39; on a side, corresponding to 21 h^{-1}_{70} Mpc (physical) at the supercluster redshift. We select galaxies whose colors correspond t

  36. Eric G. Blackman, Jason T. Nordhaus, John H. Thomas

    Observational evidence for anisotropy in supernovae (SN) may signal the importance of angular momentum and differential rotation in the progenitors. Free energy in differential rotation and rotation can be extracted magnetically or via turbulent dissipation. The importance that magnetohydrodyamic jets and coronae may play in driving SN motivates understandin

  37. A. Tawfik

    We propose the entropy density as the thermodynamic condition driving best the chemical freeze-out in heavy-ion collisions. Taking its value from lattice calculations at zero chemical potential, we find that it is excellent in reproducing the experimentally estimated freeze-out parameters. The two characteristic endpoints in the freeze-out diagram are reprod

  38. Y. Jack Ng, H. van Dam

    In general, quantum field theories (QFT) require regularizations and infinite renormalizations due to ultraviolet divergences in their loop calculations. Furthermore, perturbation series in theories like QED are not convergent series, but are asymptotic series. We apply neutrix calculus, developed in connection with asymptotic series and divergent integrals,

  39. Tiago C. Ribeiro, Xiao-Gang Wen

    We introduce a new mean field approach to the tt&#39;t&#39;&#39;J model that incorporates both electron-like quasiparticle and spinon excitations as suggested by some experiments and numerical studies. It leads to a mean field phase diagram which is consistent with that of hole and electron doped cuprates. Moreover, it provides a framework to describe the ob

  40. Ian Swanson

    Recent explorations of the AdS/CFT correspondence have unveiled integrable structures underlying both planar N = 4 super-Yang-Mills theory and type IIB string theory on AdS_5 x S^5. Integrability in the gauge theory emerges from the fact that the dilatation generator can be identified with the Hamiltonian of an integrable quantum spin chain, and the classica

  41. Simon Catterall

    We propose a discretization of two dimensional Euclidean Yang-Mills theories with N=2 supersymmetry which preserves exactly both gauge invariance and an element of supersymmetry. The approach starts from the twisted form of the continuum super Yang Mills action which we show may be written in terms of two real Kahler-Dirac fields whose components transform i

  42. Alejandro Ibarra, Eduard Masso, Javier Redondo

    We analyze four-lepton contact interactions that lead to lepton flavor violating processes, with violation of individual family lepton number but total lepton number conserved. In an effective Lagrangian framework, the assumption of gauge invariance leads to relations among branching ratios and cross sections of lepton flavor violating processes. In this pap

  43. Paul B. Slater

    Paralleling our recent computationally-intensive (quasi-Monte Carlo) work for the case N=4 (quant-ph/0308037), we undertake the task for N=6 of computing to high numerical accuracy, the formulas of Sommers and Zyczkowski (quant-ph/0304041) for the (N^2-1)-dimensional volume and (N^2-2)-dimensional hyperarea of the (separable and nonseparable) N x N density m

  44. Greg Friedman

    This is an introduction to the construction of higher-dimensional knots by spinning methods. Simple spinning of classical knots was introduced by E. Artin in 1926, and several generalizations have followed. These include twist spinning, superspinning or p-spinning, frame spinning, roll spinning, and deform spinning. We survey these constructions and some of

  45. Rachel Mandelbaum, Argyro Tasitsiomi, Uros Seljak, Andrey V. Kravtsov

    Galaxy-galaxy lensing is a powerful probe of the relation between galaxies and dark matter halos, but its theoretical interpretation requires a careful modeling of various contributions, such as the contribution from central and satellite galaxies. For this purpose, a phenomenological approach based on the halo model has been developed, allowing for fast exp

  46. Rasa Karapandza, Milos Bozovic

    We develop an empirical procedure to qunatify future company performance based on top management promises. We find that the number of future tense sentence occurrences in 10-K reports is significantly negatively correlated with the return as well as with the excess return on the company stock price. We extrapolate the same methodology to US presidential camp

  47. Mauricio Bellini

    We develop a nonperturbative quantum scalar field formalism from a noncompact Kaluza-Klein (KK) theory using the induced-matter theory of gravity during inflation. We study the particular case of a de Sitter expansion for the universe.

  48. André P. Vieira

    We report a comprehensive investigation of the low-energy properties of antiferromagnetic quantum XXZ spin chains with aperiodic couplings. We use an adaptation of the Ma-Dasgupta-Hu renormalization-group method to obtain analytical and numerical results for the low-temperature thermodynamics and the ground-state correlations of chains with couplings followi

  49. Filipe Paccetti Correia, Michael G. Schmidt, Zurab Tavartkiladze

    We discuss Fayet-Iliopoulos terms in the context of five-dimensional supergravity compactified on an orbifold. For this purpose we use our superfield formulation of the off-shell 5D SUGRA. In the case of tuned FI terms, contrary to other claims, we find BPS solutions which ensure that N=1 supersymmetry is unbroken also in warped geometries. As in the rigid c

  50. Philipp Kuhn, Joachim Krug, Frank Hausser, Axel Voigt

    The shape evolution of two-dimensional islands through periphery diffusion biased by an electromigration force is studied numerically using a continuum approach. We show that the introduction of crystal anisotropy in the mobility of edge atoms induces a rich variety of migration modes, which include oscillatory and irregular behavior. A phase diagram in the

  51. Oscar J. C. Dias, Jose&#39; P. S. Lemos

    We study in detail the quantum process in which a pair of black holes is created in a higher D-dimensional de Sitter (dS) background. The energy to materialize and accelerate the pair comes from the positive cosmological constant. The instantons that describe the process are obtained from the Tangherlini black hole solutions. Our pair creation rates reduce t

  52. T. Takagi, C. P. Pearson

    We present a photometric selection method for ULIRGs in the redshift range of z=1 -- 2. We utilize the most prominent spectral feature of ULIRGs, i.e. the silicate absorption feature at 9.7 micron and an optimized filter system at mid-infrared wavelengths. These `silicate-break&#39; galaxies could be selected by using colour anomalies owing to the silicate a

  53. Zohar Nussinov, Eduardo Fradkin

    We study the spin- 1/2 two and three dimensional Orbital Compass Models relevant to the problem of orbital ordering in transition metal oxides. We show that these systems display self-dualities and novel (gauge-like) discrete sliding symmetries. An important and surprising consequence is that these models are dual to (seemingly unrelated) recently studied mo

  54. Jeffrey M. Anderson, Zhi-Yun Li, Ruben Krasnopolsky, Roger D. Blandford

    We present the results of a series of time-dependent numerical simulations of cold, magnetocentrifugally launched winds from accretion disks. Our simulations span four and half decades of mass loading; in the context of a disk with a launching region from $0.1\AU$ to $1.0\AU$ around a $1\solarmass$ star and a field strength of about $20\gauss$ at the inner d

  55. Sofyan Iblisdir, Jérémie Roland

    We exhibit measurements for optimal state estimation which have a finite number of outcomes. This is achieved by a connection between finite optimal measurements and Gauss quadratures. The example we consider to illustrate this connection is that of state estimation on $N$ qubits, all in a same pure state. Extensions to state estimation of mixed states are a

  56. Gerhard Groessing

    The paper is withdrawn due to an error in Section 2.

  57. Elizabeth S. Allman, John A. Rhodes

    The general Markov model of the evolution of biological sequences along a tree leads to a parameterization of an algebraic variety. Understanding this variety and the polynomials, called phylogenetic invariants, which vanish on it, is a problem within the broader area of Algebraic Statistics. For an arbitrary trivalent tree, we determine the full ideal of in

  58. Massimo Giovannini

    The polarization plane of the cosmic microwave background radiation can be rotated either in a magnetized plasma or in the presence of a quintessential background with pseudoscalar coupling to electromagnetism. A unified treatment of these two phenomena is presented for cold and warm electron-ion plasmas at the pre-recombination epoch. The electron temperatu

  59. S. Bellucci, S. Krivonos, A. Sutulin

    We construct N=8 supersymmetric mechanics with four bosonic end eight fermionic physical degrees of freedom. Starting from the most general N=4 superspace action in harmonic superspace for the ({\bf 4,8,4}) supermultiplet we find conditions which make it N=8 invariant. We introduce in the action Fayet-Iliopoulos terms which give rise to potential terms. We p

  60. Ricardo Garcia-Salcedo, Nora Breton

    In this paper we present an analysis to determine the existence of singularities in spatially homogeneous anisotropic universes filled with nonlinear electromagnetic radiation. These spaces are conformal to Bianchi spaces admitting a three parameter group of motions G$_3$. For these models we study geodesic completeness. It is shown that with nonlinear elect

  61. Kasper Peeters, Jan Plefka, Marija Zamaklar

    We study the semiclassical decay of macroscopic spinning strings in AdS_5 x S^5 through spontaneous splitting of the folded string worldsheet. Based on similar considerations in flat space this decay channel is expected to dominate the full quantum computation. The outgoing strings are uniquely specified by an infinite set of conserved (local) charges with a

  62. Alexandre Lefèvre, Ludovic Berthier, Robin Stinchcombe

    We prove the emergence of spatially correlated dynamics in slowly compacting dense granular media by analyzing analytically and numerically multi-point correlation functions in a simple particle model characterized by slow non-equilibrium dynamics. We show that the logarithmically slow dynamics at large times is accompanied by spatially extended dynamic stru

  63. A. G. Borisov, F. J. García de Abajo, S. V. Shabanov

    We assert that the physics underlying the extraordinary light transmission (reflection) in nanostructured materials can be understood from rather general principles based on the formal scattering theory developed in quantum mechanics. The Maxwell equations in passive (dispersive and absorptive) linear media are written in the form of the Schrödinger equation

  64. Valeri N. Kotov, Maged Elhajal, Michael E. Zhitomirsky, Frederic Mila

    We show that the S=1/2 pyrochlore lattice with both Heisenberg and antisymmetric, Dzyaloshinsky-Moriya (DM) interactions, can order antiferromagnetically into a state with chiral symmetry, dictated by the distribution of the DM interactions. The chiral antiferromagnetic state is characterized by a small staggered magnetic moment induced by the DM interaction

  65. Malcolm P. Kennett, Claudio Chamon, Leticia F. Cugliandolo

    We introduce a lattice model for a classical doped two dimensional antiferromagnet which has no quenched disorder, yet displays slow dynamics similar to those observed in supercooled liquids. We calculate two-time spatial and spin correlations via Monte Carlo simulations and find that for sufficiently low temperatures, there is anomalous diffusion and stretc

  66. Mariano Cadoni

    We present a general method for constructing acoustic analogs of the black hole solutions of two-dimensional (2D) dilaton gravity. Because by dimensional reduction every spherically symmetric, four-dimensional (4D) black hole admits a 2D description, the method can be also used to construct analogue models of 4D black holes. We also show that after fixing th

  67. Manfred Requardt

    We show that graphs, networks and other related discrete model systems carry a natural supersymmetric structure, which, apart from its conceptual importance as to possible physical applications, allows to derive a series of spectral properties for a class of graph operators which typically encode relevant graph characteristics.

  68. Ralf Meyer

    Group cohomology of polynomial growth is defined for any finitely generated discrete group, using cochains that have polynomial growth with respect to the word length function. We give a geometric condition that guarantees that it agrees with the usual group cohomology and verify this condition for a class of combable groups. Our condition involves a chain c

  69. Kang Young Lee

    We explore the unitarity violation of the CKM matrix in the model in which the third generation fermions are subjected to the separate SU(2)$_L$ gauge interaction. With the recent LEP and SLC data at $Z$-pole and low-energy neutral current interaction data, the analysis on the parameter space of the model is updated, and the unitary violation is predicted un

  70. G. Sambandamurthy, A. Johansson, E. Peled, D. Shahar

    We present the results of a systematic study of thin-films of amorphous indium-oxide near the superconductor-insulator transition. We show that the film&#39;s resistivity follows a simple, well-defined, power-law dependence on the perpendicular magnetic field. This dependence holds well into the insulating state. Our results indicate that vortices play a cen

  71. Wayne Hu

    Dark energy constraints have forced viable alternatives that differ substantially from a cosmological constant Lambda to have an equation of state w that evolves across the phantom divide set by Lambda. Naively, crossing this divide makes the dark energy gravitationally unstable, a problem that is typically finessed by unphysically ignoring the perturbations

  72. Nathalie Deruelle, Joseph Katz

    We show how to compute the mass of a Kerr-anti-de Sitter spacetime with respect to the anti-de Sitter background in any dimension, using a superpotential which has been derived from standard Noether identities. The calculation takes no account of the source of the curvature and confirms results obtained for black holes via the first law of thermodynamics.

  73. S. Ole Warnaar

    We prove an identity for Hall--Littlewood symmetric functions labelled by the Lie algebra A_2. Through specialization this yields a simple proof of the A_2 Rogers--Ramanujan identities of Andrews, Schilling and the author.

  74. M. Trippenbach, M. Matuszewski, B. A. Malomed

    We propose an experimentally relevant scheme to create stable solitons in a three-dimensional Bose-Einstein condensate confined by a one-dimensional optical lattice, using temporal modulation of the scattering length (through ac magnetic field tuned close to the Feshbach resonance). Another physical interpretation is a possibility to create stable 3D &#34;li

  75. E. S. Guerra

    In this article we discuss the realization of atomic GHZ states involving three-level atoms in a cascade and in a lambda configuration and we show explicitly how to use this state to perform the GHZ test in which it is possible to decide between local realism theories and quantum mechanics. The experimental realizations proposed makes use the interaction of

  76. Xiao-Dong Yang, An Min Wang, Feng Xu, Jiangfeng Du

    We have developed a concrete quantum simulation scheme and experimentally simulated a pairing model on an NMR quantum computer. The design of our experiment includes choosing an appropriate initial state in order to make our scheme scalable in near future, and the accomplishment of our experiment makes use of twice Fourier transforms so that our method is ap

  77. Lutz Schimansky-Geier, Udo Erdmann, Niko Komin

    We investigate self-moving particles which prefer to hop with a certain turning angle equally distributed to the right or left. We assume this turning angle distribution to be given by a double Gaussian distribution. Based on the model of Active Brownian particles and we calculate the diffusion coefficient in dependence on the mean and the dispersion of the

  78. I. I. Trifonova, S. Z. Stefanov

    This work introduces an in vivo marker in mice from the altitude of the well, determined by this cancer.The duration of development and the altitude of the cancer well are obtained from the synchronization of the mechanics and the kinetics of the processes of normal and anomalous transport under tumor mass growth.The mechanics and the kinetics of these two t

  79. Apoorva Patel

    Information theoretic analysis of genetic languages indicates that the naturally occurring 20 amino acids and the triplet genetic code arose by duplication of 10 amino acids of class-II and a doublet genetic code having codons NNY and anticodons $\overleftarrow{\rm GNN}$. Evidence for this scenario is presented based on the properties of aminoacyl-tRNA synth

  80. V. Livina, S. Tuzov, S. Havlin, A. Bunde

    We study the statistics of the recurrence times between earthquakes above a certain magnitude M$ in California. We find that the distribution of the recurrence times strongly depends on the previous recurrence time $τ_0$. As a consequence, the conditional mean recurrence time $\hat τ(τ_0)$ between two events increases monotonically with $τ_0$. For $τ_0$ well

  81. Adrian C. Melissinos

    We point out that even the most intense laser beams available today can provide only a very small fraction of the beam energy required to reach the design luminosity for a future e+e- linear collider. This fact seems to have been overlooked in the extensive literature on laser acceleration of charged particles.

  82. Andrei G. Borisov, Sergei V. Shabanov

    Maxwell&#39;s equations for electrodynamics of dispersive and absorptive (passive) media are written in the form of the Schrödinger equation with a non-Hermitian Hamiltonian. The Lanczos time-propagation scheme is modified to include non-Hermitian Hamiltonians and used, in combination with the Fourier pseudospectral method, to solve the initial-value problem

  83. Andrei G. Borisov, Sergei V. Shabanov

    Maxwell&#39;s equations are cast in the form of the Schrödinger equation. The Lanczos propagation method is used in combination with the fast Fourier pseudospectral method to solve the initial value problem. As a result, a time-domain, unconditionally stable, and highly efficient numerical algorithm is obtained for the propagation and scattering of broad-ban

  84. Andrei P. Kirilyuk

    A system of two initially homogeneous, physically real fields uniformly attracted to each other is considered as the simplest basis of the self-developing world structure. It is shown that the system is unstable against periodic cycles of self-amplified, essentially nonlinear squeeze of its extended part to a small volume around randomly chosen centre, follo

  85. S. Gordienko, A. Pukhov

    The similarity theory is derived for ultra-relativistic laser-plasma interactions. First, it is shown that the most fundamental S-similarity is valid for both under- and overdense plasmas. Then, the particular case of tenious plasma is considered in great detail. It is shown that the electron dynamics in this case has two characteristic scales. The fast scal

  86. Valeriy Chernyak, Vadym Naumov, Vitaliy Yukhimenko

    Spectroscopic characterization of a specific case of the atmospheric pressure air jet plasma in the transverse cw dc arc discharge of high voltage was done. Within the spectrum of wavelengths from 200 to 1100 nm all remarkable emissions were monitored, and all excited atomic lines of N, O, H and molecular bands of NO, N2, O2, OH, CO, CN were identified. Usin

  87. A. I. Steshenko

    A new model for calculating the structure of bound states of interacting particles is considered. The model takes into account the noncommutativity of the space and impulse operators plus the correlation equations for the indeterminacy of these quantities. The efficiency of the model is demonstrated by specific calculations for some lightest nuclei.

  88. S. Mallik, Hiranmaya Mishra

    We derive QCD sum rules from the nucleon two-point function in nuclear medium, calculating its specral function in chiral perturbation theory to one loop. Our calculation shows the inadequacy of the commonly used ansatz to represent the two-point function as the sum of a nucleon pole term and a spectral integral over the high energy continuum. We also point

  89. K. Wang, Y. G. Ma, Y. B. Wei, X. Z. Cai

    Langevin equation is used to simulate the fission process of $^{112}$Sn + $^{112}$Sn and $^{116}$Sn + $^{116}$Sn. The mass distribution of the fission fragments are given by assuming the process of symmetric fission or asymmetric fission with the Gaussian probability sampling. Isoscaling behavior has been observed from the analysis of fission fragments of bo

  90. H. A. Alhendi, H. H. Alharbi, S. U. El-Khamisi

    A modified version of the exponential model with paring attenuation is proposed, and used to describe successfully the backbending of the moment of inertia, in even-even nuclei, not only in well-deformed nuclei but also in slightly deformed nuclei. The model remarkably fits good the experimental observation with a few parameters.

  91. B. F. Bayman, F. Zardi

    This paper has been withdrawn because it draws incorrect conclusions from the results of its calculations.

  92. D. Flierl

    The hadronic final state of central Pb+Pb collisions at 20, 30, 40, 80, and 158 AGeV has been measured by the CERN NA49 collaboration. The mean transverse mass of pions and kaons at midrapidity stays nearly constant in this energy range, whereas at lower energies, at the AGS, a steep increase with beam energy was measured. Compared to p+p collisions as well

  93. Juan Sanchez, Ricardo Lopez-Ruiz

    Complex patterns generated by the time evolution of a one-dimensional digitalized coupled map lattice are quantitatively analyzed. A method for discerning complexity among the different patterns is implemented. The quantitative results indicate two zones in parameter space where the dynamics shows the most complex patterns. These zones are located on the two

  94. David Damanik, Daniel Lenz, Günter Stolz

    We prove quantum dynamical lower bounds for one-dimensional continuum Schrödinger operators that possess critical energies for which there is slow growth of transfer matrix norms and a large class of compactly supported initial states. This general result is applied to a number of models, including the Bernoulli-Anderson model with a constant single-site pot

  95. A. W. Beckwith

    Using Bogomil&#39;nyi inequality and the vanishing of topological charge at the unset of nucleation of a new universe permits a simpler,more direct insight into how topological defects (kinks and anti kinks) contribute to initial conditions at the onset of inflationary cosmology. Currently, there are few bridges between initial conditions for cosmological in

  96. A. W. Beckwith

    We first present how to do a computer simulation of Charge Density Waves using a driven harmonic oscillator model by a numerical scheme as initially formulated by Littlewood, and then afterwards use this to present how the dielectric model as presented by this proceedure leads to a blow up at the initialization of a threshold field ET. We find that this is h

  97. Joa Weber

    For every nontrivial free homotopy class $α$ of loops in every closed connected Riemannian manifold $M$, we prove existence of a noncontractible 1-periodic orbit, for every compactly supported time-dependent Hamiltonian on the open unit cotangent bundle which is sufficiently large over the zero section. The proof shows that the Biran-Polterovich-Salamon capa

  98. D. Shklyarov, S. Sinel&#39;shchikov, L. Vaksman

    In this paper we study the Fock representation of a certain $*$-algebra which appears naturally in the framework of quantum group theory. It is also a generalization of the twisted CCR-algebra introduced by W. Pusz and S.~Woronowicz. We prove that the Fock representation is a faithful irreducible representation of the algebra by bounded operators in a Hilber

  99. E. Carlini

    A presentation of a degree $d$ form in $n+1$ variables as the sum of homogenous elements ``essentially&#39;&#39; involving $n$ variables is called a {\em codimension one decomposition}. Codimension one decompositions are introduced and the related Waring Problem is stated and solved. Natural schemes describing the codimension one decompositions of a generic

  100. Kamran Divaani-Aazar, Amir Mafi

    Let $\fa$ be an ideal of a commutative Noetherian ring $R$ and $M$ a finitely generated $R$-module. Let $t$ be a natural integer. It is shown that there is a finite subset $X$ of $\Spec R$, such that $\Ass_R(H_{\fa}^t(M))$ is contained in $X$ union with the union of the sets $\Ass_R(\Ext_R^j(R/\fa,H_{\fa}^i(M)))$, where $0\leq i<t$ and $0\leq j\leq t^2+1$. A