Cross-listings

gr-qc/0502090 [abs, ps, pdf, other] :: Title: What does the Letelier-Gal'tsov metric describe?
Authors: S. Krasnikov
Comments: 4pages, 1 figure. v2 A few words are changed in accordance with the published version
Journal-ref: Class. Quantum Grav. v.23 (2006) p.573

Recently the structure of the Letelier-Gal'tsov spacetime has become a matter of some controversy. I show that the metric proposed in \cite{letgal} is defined only on a dense subset of the whole manifold. In the case when it can be defined on the remainder by continuity, the resulting spacetime corresponds to a system of parallel cosmic strings at rest w.r.t. each other.
gr-qc/0512028 [abs, ps, pdf, other] :: Title: A Finite Element Computation of the Gravitational Radiation emitted by a Point-like object orbiting a Non-rotating Black Hole
Authors: Carlos F. Sopuerta, Pablo Laguna (Penn State)
Comments: RevTeX 4. 18 pages, 8 figures

The description of extreme-mass-ratio binary systems in the inspiral phase is a challenging problem in gravitational wave physics with significant relevance for the space interferometer LISA. The main difficulty lies in the evaluation of the effects of the small body's gravitational field on itself. To that end, an accurate computation of the perturbations produced by the small body with respect the background geometry of the large object, a massive black hole, is required. In this paper we present a new computational approach based on Finite Element Methods to solve the master equations describing perturbations of non-rotating black holes due to an orbiting point-like object. The numerical computations are carried out in the time domain by using evolution algorithms for wave-type equations. We show the accuracy of the method by comparing our calculations with previous results in the literature. Finally, we discuss the relevance of this method for achieving accurate descriptions of extreme-mass-ratio binaries.
gr-qc/0601001 [abs, ps, pdf, other] :: Title: Coupling of Radial and Axial non-Radial Oscillations of Compact Stars: Gravitational Waves from first-order Differential Rotation
Authors: A. Passamonti, M. Bruni, L. Gualtieri, A. Nagar, C. F. Sopuerta
Comments: RevTeX 4. 23 pages, 13 figures

We investigate the non-linear coupling between radial and non-radial oscillations of static spherically symmetric neutron stars as a possible mechanism for the generation of gravitational waves that may lead to observable signatures. In this paper we concentrate on the axial sector of the non-radial perturbations. By using a multi-parameter perturbative framework we introduce a complete description of the non-linear coupling between radial and axial non-radial oscillations; we study the gauge invariant character of the associated perturbative variables and develop a computational scheme to evolve the non-linear coupling perturbations in the time domain. We present results of simulations corresponding to different physical situations and discuss the dynamical behaviour of this non-linear coupling. Of particular interest is the occurrence of signal amplifications in the form of resonance phenomena when a frequency associated with the radial pulsations is close to a frequency associated with one of the axial w-modes of the star. Finally, we mention possible extensions of this work and improvements towards more astrophysically motivated scenarios.
gr-qc/0601042 [abs, ps, pdf, other] :: Title: Hyperbolic heat equation in Kaluza's magnetohydrodynamics
Authors: A. Sandoval-Villalbazo, A. L. Garcia-Perciante, L. S. Garcia-Colin
Comments: 14 pages, no figures

This paper shows that a hyperbolic equation for heat conduction can be obtained directly using the tenets of linear irreversible thermodynamics in the context of the five dimensional space-time metric originally proposed by T. Kaluza back in 1922. The associated speed of propagation is slightly lower than the speed of light by a factor inversely proportional to the specific charge of the fluid element. Moreover, consistency with the second law of thermodynamics is achieved. Possible implications in the context of physics of clusters of galaxies of this result are briefly discussed.
hep-ph/0510261 [abs, ps, pdf, other] :: Title: Possible violation of the spin-statistics relation for neutrinos: checking through future galactic supernova
Authors: Sandhya Choubey, Kamales Kar
Comments: Discussion on "pinching" of Fermi-Dirac spectrum for supernova neutrinos added. Version to appear in PLB

We use the detection of neutrinos from a future galactic type-II supernova event in a water Cerenkov detector like Super-Kamiokande to constrain the possible violation of spin-statistics by neutrinos resulting in their obeying a mixed statistics instead of Fermi-Dirac.
hep-ph/0601098 [abs, ps, pdf, other] :: Title: The masses of active neutrinos in the nuMSM from X-ray astronomy
Authors: A. Boyarsky, A. Neronov, O. Ruchayskiy, M. Shaposhnikov
Comments: 6 pages. revtex4

In an extention of the Standard Model by three relatively light right-handed neutrinos (the nuMSM model) the role of the dark matter particle is played by the lightest sterile neutrino. We demonstrate that the observations of the extragalactic X-ray background allow to put a strong upper bound on the mass of the lightest active neutrino and predict the absolute values of the mass of the two heavier active neutrinos in the nuMSM, provided that the mass of the dark matter sterile neutrino is larger than 1.8 keV.

Replacements

astro-ph/0510141 [abs, ps, pdf, other] :: Title: The short-duration GRB 050724 host galaxy in the context of the long-duration GRB hosts
Authors: J. Gorosabel, A.J. Castro-Tirado, S. Guziy, A. de Ugarte Postigo, D. Reverte, A. Antonelli, S. Covino, D. Malesani, D. Martín-Gordón, A. Melandri, M. Jelínek, O. Bogdanov, N. Elias de la Rosa, J.M. Castro Cerón
Comments: A&A in press
Note: replaced with revised version Fri, 13 Jan 2006 18:25:09 GMT (35kb)
astro-ph/0511358 [abs, ps, pdf, other] :: Title: The Dust cloud around the White Dwarf G 29-38
Authors: William T. Reach, Marc J. Kuchner, Ted von Hippel, Adam Burrows, Fergal Mullally, Mukremin Kilic, D. E. Winget
Comments: accepted for publication in the Astrophysical Journal Letters
Journal-ref: 2005, Astrophysical Journal Letters, volume 635, page L161
Note: replaced with revised version Fri, 13 Jan 2006 18:04:39 GMT (59kb)
astro-ph/0512268 [abs, ps, pdf, other] :: Title: Subaru IR Echelle Spectroscopy of Herbig-Haro Driving Sources I. H_2 and [Fe II] Emission
Authors: M. Takami, A. Chrysostomou, T. P. Ray, C. J. Davis, W. R. F. Dent, J. Bailey, M. Tamura, H. Terada, T. S. Pyo
Comments: 41 pages, 9 figures, 5 tables, one of the author institutions revised
Note: replaced with revised version Fri, 13 Jan 2006 00:20:14 GMT (690kb)
astro-ph/0601262 [abs, ps, pdf, other] :: Title: The influence of grain rotation on the structure of dust aggregates
Authors: D. Paszun, C. Dominik
Comments: 15 pages, 6 figures, accepted for publication in Icarus, typos corrected
Note: replaced with revised version Fri, 13 Jan 2006 11:45:25 GMT (231kb)

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Cross-listings

gr-qc/0505017 [abs, ps, pdf, other] :: Title: Semiclassical quantisation of space-times with apparent horizons
Authors: Arundhati Dasgupta
Comments: 52 pages, 4 figures
Journal-ref: Class. Quant. Grav. 23 (2006) 635

Coherent or semiclassical states in canonical quantum gravity describe the classical Schwarzschild space-time. By tracing over the coherent state wavefunction inside the horizon, a density matrix is derived. Bekenstein-Hawking entropy is obtained from the density matrix, modulo the Immirzi parameter. The expectation value of the area and curvature operator is evaluated in these states. The behaviour near the singularity of the curvature operator shows that the singularity is resolved. We then generalise the results to space-times with spherically symmetric apparent horizons.
gr-qc/0601053 [abs, ps, pdf, other] :: Title: Formalism for testing theories of gravity using lensing by compact objects. II: Probing Post-Post-Newtonian metrics
Authors: Charles R. Keeton (Rutgers), A. O. Petters (Duke)
Comments: submitted

We study gravitational lensing by compact objects in gravity theories that can be written in a Post-Post-Newtonian (PPN) framework: i.e., the metric is static and spherically symmetric, and can be written as a Taylor series in m/r, where m is the gravitational radius of the compact object. Working invariantly, we compute corrections to standard weak-deflection lensing observables at first and second order in the ratio of the angular gravitational radius to the angular Einstein ring radius of the lens. We show that the first-order corrections to the total magnification and centroid position vanish universally for gravity theories that can be written in the PPN framework. This arises from some surprising, fundamental relations among the lensing observables in PPN gravity models. We derive these relations for the image positions, magnifications, and time delays. A deep consequence is that any violation of the universal relations would signal the need for a gravity model outside the PPN framework (provided that some basic assumptions hold). In practical terms, the relations will guide observational programs to test general relativity, modified gravity theories, and possibly the Cosmic Censorship conjecture. We use the new relations to identify lensing observables that are accessible to current or near-future technology, and to find combinations of observables that are most useful for probing the spacetime metric. We give explicit applications to the Galactic black hole, microlensing, and the binary pulsar J0737-3039.
gr-qc/0601054 [abs, ps, pdf, other] :: Title: Helicity-Rotation-Gravity Coupling for Gravitational Waves
Authors: Jairzinho Ramos, Bahram Mashhoon
Comments: 11 pages, no figures

The consequences of spin-rotation-gravity coupling are worked out for linear gravitational waves. The coupling of helicity of the wave with the rotation of a gravitational-wave antenna is investigated and the resulting modifications in the Doppler effect and aberration are pointed out for incident high-frequency gravitational radiation. Extending these results to the case of a gravitomagnetic field via the gravitational Larmor theorem, the rotation of linear polarization of gravitational radiation propagating in the field of a rotating mass is studied. It is shown that in this case the linear polarization state rotates by twice the Skrotskii angle as a consequence of the spin-2 character of linear gravitational waves.
hep-th/0512274 [abs, ps, pdf, other] :: Title: Non-perturbative materialization of ghosts
Authors: Roberto Emparan, Jaume Garriga
Comments: 43 pages, 12 figures

In theories with a hidden ghost sector that couples to visible matter through gravity only, empty space can decay into ghosts and ordinary matter by graviton exchange. Perturbatively, such processes can be very slow provided that the gravity sector violates Lorentz invariance above some cut-off scale. Here, we investigate non-perturbative decay processes involving ghosts, such as the spontaneous creation of self-gravitating lumps of ghost matter, as well as pairs of Bondi dipoles (i.e., lumps of ghost matter chasing after positive energy objects). We find the corresponding instantons and calculate their Euclidean action. In some cases, the instantons induce topology change or have negative Euclidean action. To shed some light on the meaning of such peculiarities, we also consider the nucleation of concentrical domain walls of ordinary and ghost matter, where the Euclidean calculation can be compared with the canonical (Lorentzian) description of tunneling. We conclude that non-perturbative ghost nucleation processes can be safely suppressed in phenomenological scenarios.

Replacements

astro-ph/0503129 [abs, ps, pdf, other] :: Title: Runaway collisions in young star clusters. I. Methods and tests
Authors: Marc Freitag (1 and 2), Frederic A. Rasio (2), Holger Baumgardt (3) ((1) Astronomisches Rechen-Institut, Heidelberg, Germany, (2) Northwestern University, Evanston, USA, (3) Sternwarte, University Bonn, Germany)
Comments: 22 pages, 15 figures. For publication in MNRAS. Paper revised to follow requests and suggestions of referee. Companion paper to Freitag, G\"urkan & Rasio 2005 (astro-ph/0503130)
Note: replaced with revised version Mon, 16 Jan 2006 18:55:57 GMT (367kb)
astro-ph/0503130 [abs, ps, pdf, other] :: Title: Runaway collisions in young star clusters. II. Numerical results
Authors: Marc Freitag (1 and 2), M. Atakan Gürkan (2), Frederic A. Rasio (2) ((1) Astronomisches Rechen-Institut, Heidelberg, Germany, (2) Northwestern University, Evanston, USA)
Comments: 23 pages, 24 figures. For publication in MNRAS. Paper revised to follow requests and suggestions of referee. Companion paper to Freitag, Rasio & Baumgardt 2005
Note: replaced with revised version Mon, 16 Jan 2006 19:14:12 GMT (748kb)
astro-ph/0505356 [abs, ps, pdf, other] :: Title: Difficulty of detecting minihalos via $\gamma$-rays from dark matter annihilation
Authors: Lidia Pieri, Enzo Branchini, Stefan Hofmann
Comments: 4 pages, four color figures. Version published on PRL
Journal-ref: Phys. ReV. Lett. 21, 95, 211301 (2005)
Note: replaced with revised version Mon, 16 Jan 2006 13:56:29 GMT (103kb)
astro-ph/0508293 [abs, ps, pdf, other] :: Title: Detectability of tensor modes in the presence of foregrounds
Authors: Mihail Amarie (1), Christopher Hirata (1), Uros Seljak (1 and 2) ((1) Princeton University, (2) ICTP)
Comments: 7 pages, 8 figures, minor modifications to match PRD version, added one reference
Journal-ref: Phys.Rev. D72 (2005) 123006
Note: replaced with revised version Sat, 14 Jan 2006 21:05:42 GMT (895kb)
astro-ph/0509220 [abs, ps, pdf, other] :: Title: Nonlinear Evolution of Cosmic Magnetic Fields and Cosmic Microwave Background Anisotropies
Authors: Hiroyuki Tashiro, Naoshi Sugiyama, Robi Banerjee
Comments: accepted for publication in Phys. Rev. D
Journal-ref: Phys.Rev. D73, 023002 (2006)
Note: replaced with revised version Sat, 14 Jan 2006 08:05:18 GMT (451kb)
astro-ph/0509564 [abs, ps, pdf, other] :: Title: Clustering of Lyman Break Galaxies at z=4 and 5 in The Subaru Deep Field: Luminosity Dependence of The Correlation Function Slope
Authors: Nobunari Kashikawa, Makiko Yoshida, Kazuhiro Shimasaku, Masahiro Nagashima, Hideki Yahagi, Masami Ouchi, Yuichi Matsuda, Matthew A. Malkan, Mamoru Doi, Masanori Iye, the SDF team
Comments: 16 pages, 17 figures, Accepted for publication in ApJ, Full resolution version is available at this http URL
Journal-ref: Astrophys.J. 637 (2006) 631
Note: replaced with revised version Fri, 13 Jan 2006 21:57:29 GMT (604kb)
astro-ph/0510078 [abs, ps, pdf, other] :: Title: The Recently-Discovered Dwarf Nova System ASAS J002511+1217.2: A New WZ Sagittae Star
Authors: M.R. Templeton, R. Leaman, P. Szkody, A. Henden, L. Cook, D. Starkey, A. Oksanen, M. Koppelman, D. Boyd, P.R. Nelson, T. Vanmunster, R. Pickard, N. Quinn, R. Huziak, M. Aho, R. James, A. Golovin, E. Pavlenko, R.I. Durkee, T.R. Crawford, G. Walker, P. Paakkonen
Comments: 24 pages, 11 figures, accepted to PASP; minor revision to add two authors and adjust text to match that of the published version. No adjustments to results or conclusions
Note: replaced with revised version Sun, 15 Jan 2006 17:28:37 GMT (459kb)
astro-ph/0510257 [abs, ps, pdf, other] :: Title: Chandra Observations of Six QSOs at z $\approx$ 3
Authors: Takamitsu Miyaji (1), Guenther Hasinger (2), Ingo Lehmann (2), Donald P. Schneider (3) ((1) Carnegie Mellon Univ. (2) Max-Planck Inst. fuer extraterrestrische Physik (3) Pennsylvania State University)
Comments: 13 Pages, 3 Figures, Astronomical Journal in press, An entry in Table 2 corrected--Log Lx for PC 1000+4751 from 44.0 (incorrect) to 45.0 (correct). A few minor errors corrected
Note: replaced with revised version Mon, 16 Jan 2006 20:07:04 GMT (37kb)
astro-ph/0511143 [abs, src] :: Title: A general relativistic argument for dark matter existence without invoking non-Keplerian rotation curves and gravitational-lensing data
Authors: C. G. Boehmer (Zacatecas)
Comments: 4 prl pages, updated references
Note: replaced with revised version Sat, 14 Jan 2006 00:42:57 GMT (0kb,I)
astro-ph/0511242 [abs, ps, pdf, other] :: Title: Three-Body Kick to a Bright Quasar out of Its Galaxy During a Merger
Authors: Loren Hoffman, Abraham Loeb (Harvard U.)
Comments: 5 pages, 2 figures, ApJ Letters, in press
Note: replaced with revised version Sat, 14 Jan 2006 17:16:42 GMT (70kb)
astro-ph/0511612 [abs, ps, pdf, other] :: Title: To probe into pulsar's interior through gravitational waves
Authors: R. X. Xu (PKU)
Comments: 16 pages, 2 figures, and 1 table, revised, accepted for publication in Astroparticle Physics
Note: replaced with revised version Sat, 14 Jan 2006 01:24:59 GMT (143kb)
astro-ph/0511682 [abs, pdf] :: Title: Discovery of a very extended X-ray halo around a quiescent spiral galaxy - the "missing link" of galaxy formation
Authors: Kristian Pedersen (1), Jesper Rasmussen (2), Jesper Sommer-Larsen (1), Sune Toft (3), Andrew J. Benson (4), Richard G. Bower (5) ((1) Dark Cosmology Centre, Copenhagen, (2) Birmingham, (3) Yale, (4) Oxford, (5) Durham)
Comments: New Astronomy, in press
Note: replaced with revised version Fri, 13 Jan 2006 22:04:10 GMT (378kb)
astro-ph/0512018 [abs, ps, pdf, other] :: Title: A Note on Crossing the Phantom Divide in Hybrid Dark Energy Model
Authors: Hao Wei, Rong-Gen Cai
Comments: 9 pages, 3 figures, Latex2e; v2: references added; v3: discussions added, accepted by Phys.Lett.B
Note: replaced with revised version Mon, 16 Jan 2006 02:07:15 GMT (37kb)
astro-ph/0512085 [abs, ps, pdf, other] :: Title: Large-scale galaxy correlations as a test for dark energy
Authors: Alain Blanchard (LATT, Toulouse), Marian Douspis (LATT, Toulouse), Michael Rowan-Robinson (Imperial College, London), Subir Sarkar (Oxford University)
Comments: 4 pages, 2 figures, revised version, accepted to A&A
Note: replaced with revised version Sun, 15 Jan 2006 21:15:28 GMT (30kb)
astro-ph/0512217 [abs, ps, pdf, other] :: Title: Anisotropy of the cosmic gamma-ray background from dark matter annihilation
Authors: Shin'ichiro Ando, Eiichiro Komatsu
Comments: 15 pages, 12 figures; minor revision, added references; accepted to PRD
Note: replaced with revised version Sat, 14 Jan 2006 06:50:56 GMT (73kb)
astro-ph/0512403 [abs, ps, pdf, other] :: Title: The Infrared Glow of First Stars
Authors: R. Salvaterra, M. Magliocchetti, A. Ferrara, R. Schneider
Comments: 4 pages, 2 figures, MNRAS in press
Note: replaced with revised version Mon, 16 Jan 2006 17:17:15 GMT (19kb)
astro-ph/0601014 [abs, ps, pdf, other] :: Title: Accelerating Universe: Observational Status and Theoretical Implications
Authors: L. Perivolaropoulos
Comments: References added. 35 pages, 17 figures. Invited Review at the Third Aegean Summer School: `The Invisible Universe Dark Matter and Dark Energy' (see this http URL). PPT file of talk available at this http URL
Note: replaced with revised version Mon, 16 Jan 2006 11:45:11 GMT (855kb)
astro-ph/0601280 [abs, ps, pdf, other] :: Title: Spatial Distribution of Faint Fuzzy Star Clusters in NGC 5195
Authors: Narae Hwang, Myung Gyoon Lee
Comments: 12 pages, 3 figures, accepted for publication in ApJ Letters (Only a few typos are corrected in the revised version)
Note: replaced with revised version Mon, 16 Jan 2006 08:27:27 GMT (67kb)
gr-qc/0512022 [abs, ps, pdf, other] :: Title: The Local Effects of Cosmological Variations in Physical 'Constants' and Scalar Fields I. Spherically Symmetric Spacetimes
Authors: Douglas J. Shaw, John D. Barrow
Comments: 30 pages, 3 figures; corrected typos
Note: replaced with revised version Sun, 15 Jan 2006 11:39:21 GMT (208kb)
hep-th/0510207 [abs, ps, pdf, other] :: Title: Brane-bulk energy exchange : a model with the present universe as a global attractor
Authors: G. Kofinas, G. Panotopoulos, T.N. Tomaras
Comments: 8 pages, 2 figures, RevTex; references added, to appear in JHEP
Note: replaced with revised version Mon, 16 Jan 2006 15:34:57 GMT (134kb)

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Cross-listings

gr-qc/0601055 [abs, ps, pdf, other] :: Title: What do the orbital motions of the outer planets of the Solar System tell us about the Pioneer anomaly?
Authors: Lorenzo Iorio
Comments: Latex2e, 12 pages, 3 tables, 4 figures
Subj-class: General Relativity and Quantum Cosmology; Space Physics

In this paper we investigate the effects that an anomalous acceleration as that experienced by the Pioneer spacecraft after they passed the 20 AU threshold would induce on the orbital motions of the Solar System planets placed at heliocentric distances of 20 AU or larger as Uranus, Neptune and Pluto. It turns out that such an acceleration, with a magnitude of about 8 X 10^-10 m s^-2, would affect their orbits with secular and short-period signals large enough to be detected with the present-day level of accuracy in orbit determination. The absence of such anomalous signatures in the latest data analyses rules out the possibility that in the region 20-40 AU of the Solar System an anomalous force field inducing a constant and radial acceleration of that size is present.
gr-qc/0601056 [abs, ps, pdf, other] :: Title: The Local Effects of Cosmological Variations in Physical 'Constants' and Scalar Fields II. Quasi-Spherical Spacetimes
Authors: Douglas J. Shaw, John D. Barrow
Comments: 13 pages, 1 figure

We investigate the conditions under which cosmological variations in physical `constants' and scalar fields are detectable on the surface of local gravitationally-bound systems, such as planets, in non-spherically symmetric background spacetimes. The method of matched asymptotic expansions is used to deal with the large range of length scales that appear in the problem. We derive a sufficient condition for the local time variation of the scalar fields driving variations in 'constants' to track their large-scale cosmological variation and show that this is consistent with our earlier conjecture derived from the spherically symmetric problem. We perform our analysis with spacetime backgrounds that are of Szekeres-Szafron type. They are approximately Schwarzschild in some locality and free of gravitational waves everywhere. At large distances, we assume that the spacetime matches smoothly onto a Friedmann background universe. We conclude that, independent of the details of the scalar-field theory describing the varying `constant', the condition for its cosmological variations to be measured locally is almost always satisfied in physically realistic situations. The very small differences expected to be observed between different scales are quantified. This strengthens the proof given in our previous paper that local experiments see global variations by dropping the requirement of exact spherical symmetry. It provides a rigorous justification for using terrestrial experiments and solar system observations to constraint or detect any cosmological time variations in the traditional `constants' of Nature in the case where non-spherical inhomogeneities exist.
gr-qc/0601061 [abs, ps, pdf, other] :: Title: Gravitational field energy contribution to the neutron star mass
Authors: M.Dyrda, B.Kinasiewicz, M.Kutschera, A. Szmaglinski
Comments: 19 pages, 18 figures

Neutron stars are discussed as laboratories of physics of strong gravitational fields. The mass of a neutron star is split into matter energy and gravitational field energy contributions. The energy of the gravitational field of neutron stars is calculated with three different approaches which give the same result. It is found that up to one half of the gravitational mass of maximum mass neutron stars is comprised by the gravitational field energy. Results are shown for a number of realistic equations of state of neutron star matter.
gr-qc/0601062 [abs, ps, pdf, other] :: Title: Classical dynamics and stability of collapsing thick shells of matter
Authors: G.L. Alberghi, R. Casadio, D. Fazi
Comments: 16 pages in IOP style, 8 figures, accepted for publication in Class. Quantum Grav

We study the collapse towards the gravitational radius of a macroscopic spherical thick shell surrounding an inner massive core. This overall electrically neutral macroshell is composed by many nested delta-like massive microshells which can bear non-zero electric charge, and a possibly non-zero cosmological constant is also included. The dynamics of the shells is described by means of Israel's (Lanczos) junction conditions for singular hypersurfaces and, adopting a Hartree (mean field) approach, an effective Hamiltonian for the motion of each microshell is derived which allows to check the stability of the matter composing the macroshell. We end by briefly commenting on the quantum effects which may arise from the extension of our classical treatment to the semiclassical level.
hep-ph/0601108 [abs, ps, pdf, other] :: Title: Black hole production in tachyonic preheating
Authors: Teruaki Suyama, Takahiro Tanaka, Bruce Bassett, Hideaki Kudoh
Comments: 6pages, 7figures

We present fully non-linear simulations of a self-interacting scalar field in the early universe undergoing tachyonic preheating. We find that density perturbations on sub-horizon scales which are amplified by tachyonic instability maintain long range correlations even during the succeeding parametric resonance, in contrast to the standard models of preheating dominated by parametric resonance. As a result the final spectrum exhibits memory and is not universal in shape. We find that throughout the subsequent era of parametric resonance the equation of state of the universe is almost dust-like, hence the Jeans wavelength is much smaller than the horizon scale. If our 2D simulations are accurate reflections of the situation in 3D, then there are wide regions of parameter space ruled out by over-production of black holes. It is likely however that realistic parameter values, consistent with COBE/WMAP normalisation, are safetly outside this black hole over-production region.
hep-th/0601097 [abs, ps, pdf, other] :: Title: Dynamical back-reaction of relic gravitons
Authors: Massimo Giovannini
Comments: 40 pages, 8 included figures

The dynamical effects of the tensor modes of the geometry are investigated in the context of curvature bounces. Since the bouncing behaviour implies sharp deviations from a radiation-dominated evolution, significant back-reaction effects of relic gravitons may be expected at short wavelengths.
After developing a general iterative framework for the calculation of dynamical back-reaction effects, explicit analytical and numerical examples are investigated for different parametrizations of the energy-momentum pseudo-tensor(s) of the produced gravitons. The reported results suggest that dynamical back-reaction effects are a necessary ingredient for a consistent description of bouncing models at late times.
hep-th/0601099 [abs, ps, pdf, other] :: Title: Observing Brane Inflation
Authors: Sarah E. Shandera, S.-H. Henry Tye
Comments: 31 pages, 12 figures

Linking the slow-roll scenario and the Dirac-Born-Infeld scenario of ultra-relativistic roll (where, thanks to the warp factor, the inflaton moves slowly even with an ultra-relativistic Lorentz factor), we find that the KKLMMT D3/anti-D3 brane inflation is robust, that is, enough e-folds of inflation is quite generic in the parameter space of the model. We show that the intermediate regime of relativistic roll can be quite interesting observationally. Introducing appropriate inflationary parameters, we explore the parameter space and give the constraints and predictions for the cosmological observables in this scenario. Among other properties, this scenario allows the saturation of the present observational bound of either the tensor/scalar ratio r (in the intermediate regime) or the non-Gaussianity f_NL (in the ultra-relativistic regime), but not both.
hep-th/0601105 [abs, ps, pdf, other] :: Title: High-energy effects on the spectrum of inflationary gravitational wave background in braneworld cosmology
Authors: Takashi Hiramatsu
Comments: 21 pages, 15 figures

We discuss the cosmological evolution of the inflationary gravitational wave background (IGWB) in the Randall-Sundrum single-brane model. In the braneworld cosmology, in which three-dimensional space-like hypersurface that we live in is embedded in five-dimensional anti de Sitter (AdS_5) space-time, the evolution of gravitational wave (GW) modes is affected by the non-standard expansion of the universe and the excitation of the Kaluza-Klein modes (KK-modes), which are significant in the high-energy regime of the universe. We numerically evaluate these two effects by solving the evolution equation for GWs propagating through the AdS_5 space-time. Using a plausible initial condition from inflation, we find that the excitation of KK-modes can be characterized by a simple scaling relation above the critical frequency f_crit determined from the length scale of the fifth dimension \ell. The remarkable point is that this relation generally holds as long as the matter content of the universe is described by the perfect fluid with the EOS p=w\rho for 0\leq w\leq 1. The resultant scaling relation is translated into the energy spectrum of the IGWB as \Omega_GW\propto f^{(3w-1)/(3w+2)} for f>f_crit. This indicates that, in the radiation dominant case (w=1/3), the two high-energy effects accidentally compensate each other and the spectrum becomes almost the same as the one predicted in the four-dimensional theory, i.e., \Omega_GW\propto f^0.

Replacements

astro-ph/0503401 [abs, ps, pdf, other] :: Title: Gemini Deep Deep Survey VI: Massive Hdelta-strong galaxies at z=1
Authors: Damien Le Borgne (1), Roberto Abraham (1), Kathryne Daniel (2), Patrick McCarthy (3), Karl Glazebrook (2), Sandra Savaglio (2), David Crampton (4), Stephanie Juneau (5,4), Ray Carlberg (1), Hsiao-Wen Chen (6), Ronald O. Marzke (7), Kathy Roth (8), Inger Jorgensen (8), Richard Murowinski (4) ((1) Univ. of Toronto, (2) John Hopkins Univ., (3) Carnegie Obs., (4) NRS Herzberg Institute, (5) Univ. of Montreal, (6) Center for Space Sciences, (7) San Francisco Univ., (8) Gemini Obs.)
Comments: 16 pages, 12 figures, 3 tables, uses emulateapj.sty; updated to match the version accepted by ApJ. One figure added, conclusions unchanged
Note: replaced with revised version Tue, 17 Jan 2006 16:03:33 GMT (626kb)
astro-ph/0507308 [abs, ps, pdf, other] :: Title: The Ups and Downs of Baryon Oscillations
Authors: Eric V. Linder
Comments: 18 pages, 3 figures; minor, but incisive, updates
Note: replaced with revised version Tue, 17 Jan 2006 18:41:46 GMT (27kb)
astro-ph/0509478 [abs, ps, pdf, other] :: Title: Non-parametric reconstruction of the primordial power spectrum at horizon scales from WMAP data
Authors: Domenico Tocchini-Valentini (Oxford), Yehuda Hoffman (HU, Jerusalem), Joseph Silk (Oxford)
Comments: 9 pages, 8 figures. Revised version accepted for publication in MNRAS
Note: replaced with revised version Tue, 17 Jan 2006 04:15:00 GMT (299kb)
astro-ph/0510765 [abs, ps, pdf, other] :: Title: The footprint of large scale cosmic structure on the ultra-high energy cosmic ray distribution
Authors: A. Cuoco, R. D' Abrusco, G. Longo, G. Miele, P. D. Serpico
Comments: 21 pages, 14 figures. Reference added, minor changes, matches published version
Journal-ref: JCAP 01 (2006) 009
Note: replaced with revised version Tue, 17 Jan 2006 14:27:40 GMT (581kb)
astro-ph/0511414 [abs, ps, pdf, other] :: Title: Clues to AGN Growth from Optically Variable Objects in the Hubble Ultra Deep Field
Authors: S. H. Cohen (1), R. E. Ryan Jr (1), A. N. Straughn (1), N. P. Hathi (1), R. A. Windhorst (1), A. M. Koekemoer (2), N. Pirzkal (2), C. Xu (2), B. Mobasher (2), S. Malhotra (2), L.-G.Strolger (2), J. E. Rhoads (2) ((1) Arizona State University, (2) STScI)
Comments: 9 pages, 6 figures, accepted for publication in Astrophysical Journal, minor changes to references
Note: replaced with revised version Tue, 17 Jan 2006 16:54:28 GMT (554kb)
astro-ph/0512368 [abs, ps, pdf, other] :: Title: Very Large Primordial Non-Gaussianity from multi-field: Application to Massless Preheating
Authors: Asko Jokinen, Anupam Mazumdar
Comments: 23 pages, JHEP style, references added
Note: replaced with revised version Tue, 17 Jan 2006 15:17:51 GMT (153kb)
astro-ph/0512381 [abs, ps, pdf, other] :: Title: Dynamical flows through Dark Matter Haloes: Inner perturbative dynamics, secular evolution, and applications
Authors: Christophe Pichon (Institut d'Astrophysique de Paris) Dominique Aubert (Sap CEA Saclay)
Comments: 35 pages, 12 Postscript figures, accepted for publication by MNRAS
Note: replaced with revised version Tue, 17 Jan 2006 13:53:52 GMT (565kb)

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cond-mat/0601307 [abs, ps, pdf, other] :: Title: Quantum coherence of Hard-Core-Bosons and Fermions : Extended, Glassy and Mott Phases
Authors: Ana Maria Rey, Indubala I. Satija, Charles W. Clark
Comments: 5 pages, 4 figures
Subj-class: Other; Cellular Automata and Lattice Gases

We use Hanbury-Brown-Twiss interferometry (HBTI) to study various quantum phases of hard core bosons (HCBs) and ideal fermions confined in a one-dimensional quasi-periodic (QP) potential. For HCBs, the QP potential induces a cascade of Mott-like band-insulator phases in the extended regime, in addition to the Mott insulator, Bose glass, and superfluid phases. At critical filling factors, the appearance of these insulating phases is heralded by a peak to dip transition in the interferogram, which reflects the fermionic aspect of HCBs. On the other hand, ideal fermions in the extended phase display various complexities of incommensurate structures such as devil's staircases and Arnold tongues. In the localized phase, the HCB and the fermion correlations are identical except for the sign of the peaks. Finally, we demonstrate that HBTI provides an effective method to distinguish Mott and glassy phases.
hep-ph/0601134 [abs, ps, pdf, other] :: Title: Running Spectral Index as a Probe of Physics at High Scales
Authors: G. Ballesteros, J.A. Casas, J.R. Espinosa
Comments: 33 pages, LaTeX, 5 ps figures

The WMAP results on the scalar spectral index n and its running with scale, though preliminary, open a very interesting window to physics at very high energies. We address the problem of finding inflaton potentials well motivated by particle physics which can accomodate WMAP data. We make a model independent analysis of a large class of models: those with flat tree-level potential lifted by radiative corrections, which cause the slow rolling of the inflaton and the running of n. This includes typical hybrid inflation models. In the small-coupling regime the predictions for the size and running of n are remarkably neat, e.g. -dn/dln k=(n-1)^2 << 1, and n does not cross n=1, contrary to WMAP indications. On the other hand, n can run significantly if the couplings are stronger but at the price of having a small number of e-folds, Ne. We also examine the effect of mass thresholds crossed during inflation. Finally, we show that the presence of non-renormalizable operators for the inflaton, suppressed by a mass scale above the inflationary range, is able to give both dn/dln k ~ O(-0.05) and Ne ~ 50.

Replacements

astro-ph/0507094 [abs, ps, pdf, other] :: Title: VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO
Authors: N. Haering-Neumayer, M. Cappellari, H.-W. Rix, M. Hartung, M. A. Prieto, K. Meisenheimer, R. Lenzen
Comments: 12 pages, 14 figures, including minor changes following the referee report; accepted for publication in The Astrophysical Journal
Note: replaced with revised version Wed, 18 Jan 2006 14:42:26 GMT (304kb)
astro-ph/0509269 [abs, ps, pdf, other] :: Title: Limits on spin-dependent WIMP-nucleon interactions from the Cryogenic Dark Matter Search
Authors: CDMS Collaboration
Comments: 5 pages, 4 figures; replacement to match published version
Journal-ref: Phys. Rev. D 73, 011102(R) (2006)
Note: replaced with revised version Tue, 17 Jan 2006 23:45:30 GMT (26kb)
astro-ph/0510614 [abs, ps, pdf, other] :: Title: Truncated disc versus extremely broad iron line in XTE J1650-500
Authors: Chris Done, Marek Gierlinski
Comments: Accepted for publication in MNRAS
Note: replaced with revised version Wed, 18 Jan 2006 14:22:53 GMT (65kb)
astro-ph/0601007 [abs, ps, pdf, other] :: Title: Parametrization of K-essence and Its Kinetic Term
Authors: Hui Li, Zong-Kuan Guo, Yuan-Zhong Zhang
Comments: 8 pages, 1 figure; accepted by Mod. Phys. Lett. A; minor changes to references
Note: replaced with revised version Wed, 18 Jan 2006 06:16:15 GMT (20kb)
gr-qc/0508115 [abs, ps, pdf, other] :: Title: Stable dark energy stars
Authors: Francisco S. N. Lobo
Comments: 10 pages, 6 figures, Revtex4. V2: comments and references added, 11 pages. V3: Significant additions and clarifications, 12 pages
Note: replaced with revised version Tue, 17 Jan 2006 23:41:56 GMT (152kb)

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cond-mat/0601409 [abs, ps, pdf, other] :: Title: Comment on "Entropy of Classical Systems with Long-Range Interactions" by T.M. Rocha Filho et al, PRL 95, 190601 (2005)
Authors: A. Rapisarda, A. Pluchino, C. Tsallis
Comments: 1 page, no figures
Subj-class: Statistical Mechanics; Plasma Physics

In a recent letter (PRL 95, 190601 (2005)), T.M. Rocha Filho and coworkers address the very interesting issue of the entropic form to be used for Hamiltonians with long-range interactions. In our opinion the letter misses several points quite debated in the recent literature which are of fundamental importance for a complete discussion of this problem. Moreover it contains several statements which are not true or not corroborated by any evidence. In this comment we discuss these arguments and severely question the generality of the conclusions of this letter.
hep-ph/0512179 [abs, ps, pdf, other] :: Title: Probing the Cosmic Ray "Knee" and Very High Energy Prompt Muon and Neutrino fluxes via Underground Muons
Authors: Raj Gandhi, Sukanta Panda
Comments: 20 pages, 8 figures, 4 tables, typos added and corrected

We calculate event rate and demonstrate the observational feasibility of very high energy muons (1 TeV-1000 TeV) in a large mass underground detector operating as a pair-meter. This energy range corresponds to surface muon energies of $\sim$(2 TeV - 5000 TeV) and primary cosmic ray energies of $\sim$ (20 TeV - 5 $\times 10^4$ TeV). Such measurements would significantly assist in an improved understanding of the prompt contribution to $\nu_e, \nu_{\mu}$ and $\mu$ fluxes in present and future ultra-high energy neutrino detectors. In addition, they would shed light on the origin of the observed 'knee' in the cosmic ray spectrum.
hep-ph/0601147 [abs, ps, pdf, other] :: Title: Cosmological implication of antisymmetric tensor field on D-brane
Authors: Inyong Cho, Eung Jin Chun, Hang Bae Kim, Yoonbai Kim
Comments: 15 pages, 5 figures. To appear in the proceedings of the 9th Italian-Korean Symposium on Relativistic Astrophysics, Seoul, South Korea, and Mt. Kumgang, North Korea, 19-24 Jul. 2005. Submitted to J. Korean Phys. Soc

We discuss cosmological implications of antisymmetric tensor field when it experiences a kind of ``Higgs mechanism'' including nonlocal interaction terms on D-branes. Even when a huge magnetic condensation inducing anisotropy was assumed in the early universe, the expansion of the universe leads to the isotropic $B$-matter dominated universe.
hep-th/0601110 [abs, ps, pdf, other] :: Title: Exact Black Holes and Gravitational Shockwaves on Codimension-2 Branes
Authors: Nemanja Kaloper, Derrick Kiley
Comments: 18 pages, LaTeX

We derive exact gravitational fields of a black hole and a relativistic particle stuck on a codimension-2 brane in $D$ dimensions when gravity is ruled by the bulk $D$-dimensional Einstein-Hilbert action. The black hole is locally the higher-dimensional Schwarzschild solution, which is threaded by a tensional brane yielding a deficit angle and includes the first explicit example of a `small' black hole on a tensional 3-brane. The shockwaves allow us to study the large distance limits of gravity on codimension-2 branes. In an infinite locally flat bulk, they extinguish as $1/r^{D-4}$, i.e. as $1/r^2$ on a 3-brane in $6D$, manifestly displaying the full dimensionality of spacetime. We check that when we compactify the bulk, this special case correctly reduces to the 4D Aichelburg-Sexl solution at large distances. Our examples show that gravity does not really obstruct having general matter stress-energy on codimension-2 branes, although its mathematical description may be more involved.

Replacements

astro-ph/0111313 [abs, ps, pdf, other] :: Title: Nonaxisymmetric stability in the shearing sheet approximation
Authors: Axel Brandenburg (Nordita), Boris Dintrans (Observatoire Midi-Pyrenees)
Comments: 8 pages, 7 figures, A&A (in press)
Note: replaced with revised version Thu, 19 Jan 2006 09:29:30 GMT (153kb)
astro-ph/0407329 [abs, ps, pdf, other] :: Title: Multiverses and Cosmology: Philosophical Issues
Authors: W. R. Stoeger, G. F. R. Ellis, U. Kirchner
Comments: 37 pages
Note: replaced with revised version Thu, 19 Jan 2006 18:53:06 GMT (42kb)
astro-ph/0410645 [abs, ps, pdf, other] :: Title: Magnetic field generation in fully convective rotating spheres
Authors: W. Dobler (Univ. Calgary, KIS), M. Stix (KIS), A. Brandenburg (NORDITA)
Comments: 12 pages, 11 figures, 2 tables, to appear in the 10 Feb issue of ApJ
Note: replaced with revised version Thu, 19 Jan 2006 19:55:25 GMT (673kb)
astro-ph/0511239 [abs, ps, pdf, other] :: Title: The BATSE-Swift luminosity and redshift distributions of short-duration GRBs
Authors: Dafne Guetta, Tsvi Piran
Comments: Revised version includes additional bursts and revised redshift of older bursts
Note: replaced with revised version Thu, 19 Jan 2006 07:16:12 GMT (142kb)
astro-ph/0511738 [abs, ps, pdf, other] :: Title: Equilibrium of large astrophysical structures in the Newton-Hooke spacetime
Authors: A. Balaguera-Antolinez, M. Nowakowski
Comments: References added
Journal-ref: Astron.Astrophys. 441 (2005) 23
Note: replaced with revised version Thu, 19 Jan 2006 16:30:19 GMT (451kb)
astro-ph/0512017 [abs, ps, pdf, other] :: Title: Cosmic microwave background multipole alignments in slab topologies
Authors: James G. Cresswell, Andrew R. Liddle, Pia Mukherjee, Alain Riazuelo
Comments: 6 pages RevTex with 6 figures included. Minor changes to match version accepted as Physical Review D Rapid Communication
Note: replaced with revised version Thu, 19 Jan 2006 11:08:05 GMT (26kb)
astro-ph/0512592 [abs, ps, pdf, other] :: Title: Galactic dynamo and helicity losses through fountain flow
Authors: Anvar Shukurov (Newcastle), Dmitry Sokoloff (Moscow), Kandaswamy Subramanian (IUCAA), Axel Brandenburg (Nordita)
Comments: 4 pages, 2 figures, accepted by A&A Letters
Note: replaced with revised version Thu, 19 Jan 2006 17:35:57 GMT (37kb)
astro-ph/0512608 [abs, ps, pdf, other] :: Title: The origin and evolution of cluster magnetism
Authors: A. Shukurov (Newcastle), K. Subramanian (IUCAA), N. E. L. Haugen (Trondheim)
Comments: 4 pages, 1 figure, accepted by Astronomische Nachrichten (proceedings of "The Origin and Evolution of Cosmic Magnetism", 29 August - 2 September 2005, Bologna, Italy)
Note: replaced with revised version Thu, 19 Jan 2006 17:46:10 GMT (357kb)
astro-ph/0601190 [abs, pdf] :: Title: Short Gamma-Ray Bursts with Extended Emission
Authors: Jay P. Norris, Jerry T. Bonnell
Comments: 26 pages, 8 figures, 4 tables. Now accepted for publication in The Astrophysical Journal
Note: replaced with revised version Thu, 19 Jan 2006 19:33:27 GMT (410kb)
astro-ph/0601229 [abs, ps, pdf, other] :: Title: GeV-TeV and X-ray flares from gamma-ray burst
Authors: Xiang-Yu Wang (PSU, NJU), Zhuo Li (Weizmann Inst), Peter Meszaros (PSU)
Comments: Submitted to ApJL, 12 pages, 1 figure, typos corrected
Note: replaced with revised version Wed, 18 Jan 2006 22:12:52 GMT (21kb)

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