Date: Thu, 26 Feb 09 01:00:27 GMT Subject: gr-qc daily 4 new + 3 crosses received by eprepget ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ Send any complaints regarding submissions directly to submitter. ------------------------------------------------------------------------------ Point your www client at http://arXiv.org/ To unsubscribe, e-mail To: gr-qc@arXiv.org, Subject: cancel ------------------------------------------------------------------------------ received by eprepget from Tue 24 Feb 09 21:00:01 GMT to Wed 25 Feb 09 21:00:01 GMT ------------------------------------------------------------------------------ \\ arXiv:0902.4318 Date: Wed, 25 Feb 2009 08:56:14 GMT (8kb) Title: The Weight of Vacuum Fluctuations Authors: Eduard Masso (Univ. Autonoma Barcelona) Categories: gr-qc astro-ph.CO Comments: 7 pages Report-no: UAB-FT-663 \\ We examine the gravitational properties of Lamb shift energies. Using available experimental data we show that these energies have a standard gravitational behavior at the level of $\sim 10^{-5}$. We are motivated by the point of view that Lamb shift energies may be interpreted as a consequence of vacuum fluctuations of the electromagnetic field, since in this case we are testing the gravitational properties of quantum fluctuations. Our result might be of interest in relation to the problem of the zero-point energy contribution to the cosmological constant. Indeed, the problem presupposes that the zero-point energy gravitates as all other forms of energy, and this supposition is what we test. \\ ( http://arxiv.org/abs/0902.4318 , 8kb) ------------------------------------------------------------------------------ \\ arXiv:0902.4346 Date: Wed, 25 Feb 2009 11:27:27 GMT (7kb) Title: Dark energy and quantum vacuum fluctuations Authors: Emilio Santos Categories: gr-qc Comments: 9 pages, no figures \\ It is suggested that the vacuum expectation of the quantum vacuum energy-momentum is zero, but quantum fluctuations give rise to a space-time curvature equivalent to that of a cosmological constant or dark energy. Calculations within quantized gravity, following a few plausible hypotheses, provide results compatible with cosmological observations. \\ ( http://arxiv.org/abs/0902.4346 , 7kb) ------------------------------------------------------------------------------ \\ arXiv:0902.4432 Date: Wed, 25 Feb 2009 17:53:09 GMT (22kb,D) Title: On the choice of coupling procedure for the Poincar\'e gauge theory of gravity Authors: Marcin Ka\'zmierczak Categories: gr-qc Comments: 15 pages \\ The gauge approach to the theory of gravity has been widely discussed as an alternative to standard general relativity. The Poincar\'e group, as a symmetry group of all relativistic theories in the absence of gravitation, constitutes the most natural candidate for a gauge group. Although the Poincar\'e gauge theory of gravity has been elaborated over the years and cast into a beautiful formal framework, some fundamental problems remained unsolved. One of them concerns the inclusion of matter. The minimal coupling procedure, which is employed in standard Yang--Mills theories, appears to be ambiguous in the case of gravity. We propose a slight modification of this procedure, which removes the ambiguity. Our modification justifies some earlier results concerning the consequences of the Poincar\'e gauge theory of gravity. In particular, the predictions of Einstein--Cartan theory with fermionic matter are rendered unique. We recall the earlier proposed solution based on modified volume--forms. The advantage of our modification is that the predictions of the theory are not radically changed. Basically, this modification simply justifies the results that were obtained partly `by chance' in the hitherto prevailing accounts on the Einstein--Cartan theory. The only difference in the predictions, while compared to the standard treatment, concerns the Proca field in the presence of gravity. The `torsion singularities' which occur there are shifted towards other values of the field. \\ ( http://arxiv.org/abs/0902.4432 , 22kb) ------------------------------------------------------------------------------ \\ arXiv:0902.4439 Date: Wed, 25 Feb 2009 18:43:22 GMT (16kb) Title: Class of Einstein-Maxwell Phantom Fields: Rotating and Magnetised Wormholes Authors: Tonatiuh Matos Categories: gr-qc Comments: 15 pages, no figures Report-no: CIEA/09-gr5 \\ Using a new ansatz for solving the Einstein equations with a scalar field with the sign of the kinetic term inverted, I find a series of formulae to derive axial symmetric stationary exact solutions of the Phantom scalar field in general relativity. We focus on the solutions which represent wormholes. The procedure presented in this work allows to derive new exact solutions up to very simple integrations. Among other results, I find exact rotating solutions containing magnetic monopoles, dipoles, etc., coupled to Phantom scalar and to gravitational multipole fields. \\ ( http://arxiv.org/abs/0902.4439 , 16kb) %-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%- ------------------------------------------------------------------------------ \\ arXiv:0902.3667 (*cross-listing*) Date: Fri, 20 Feb 2009 21:05:58 GMT (13kb) Title: P-nflation: generating cosmic Inflation with p-forms Authors: Cristiano Germani (LUTH, Observatoire de Paris-Meudon) and Alex Kehagias (NTUA, Athens) Categories: astro-ph.CO gr-qc hep-th Comments: 14 pages; JCAP style \\ We show that an inflationary background might be realized by using any p-form non-minimally coupled to gravity. Standard scalar field inflation corresponds to the 0-form case and vector inflation to the 1-form. Moreover, we show that the 2- and 3-form fields are dual to a new vector and scalar inflationary theories where the kinetic terms are non-minimally coupled to gravity. \\ ( http://arxiv.org/abs/0902.3667 , 13kb) ------------------------------------------------------------------------------ \\ arXiv:0902.4186 (*cross-listing*) Date: Tue, 24 Feb 2009 16:48:57 GMT (39kb) Title: All null supersymmetric backgrounds of N=2, D=4 gauged supergravity coupled to abelian vector multiplets Authors: Dietmar Klemm and Emanuele Zorzan Categories: hep-th gr-qc Comments: 55 pages, uses JHEP3.cls Report-no: IFUM-933-FT \\ The lightlike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to an arbitrary number of abelian vector multiplets are classified using spinorial geometry techniques. The solutions fall into two classes, depending on whether the Killing spinor is constant or not. In both cases, we give explicit examples of supersymmetric backgrounds. Among these BPS solutions, which preserve one quarter of the supersymmetry, there are gravitational waves propagating on domain walls or on bubbles of nothing that asymptote to AdS_4. Furthermore, we obtain the additional constraints obeyed by half-supersymmetric vacua. These are divided into four categories, that include bubbles of nothing which are asymptotically AdS_4, pp-waves on domain walls, AdS_3 x R, and spacetimes conformal to AdS_3 times an interval. \\ ( http://arxiv.org/abs/0902.4186 , 39kb) ------------------------------------------------------------------------------ \\ arXiv:0902.4191 (*cross-listing*) Date: Tue, 24 Feb 2009 17:15:51 GMT (33kb,D) Title: Holonomy Loops, Spectral Triples & Quantum Gravity Authors: Johannes Aastrup, Jesper M. Grimstrup, Ryszard Nest Categories: hep-th gr-qc math-ph math.MP Comments: 24 pages, 7 figures, based on talk given by J.M.G. at the QG2 conference, Nottingham, juli 2008; at the QSTNG conference in Rome in sept/oct 2008; at the AONCG conference, Canberra, dec. 2008 \\ We review the motivation, construction and physical interpretation of a semi-finite spectral triple obtained through a rearrangement of central elements of loop quantum gravity. The triple is based on a countable set of oriented graphs and the algebra consists of generalized holonomy loops in this set. The Dirac type operator resembles a global functional derivation operator and the interaction between the algebra of holonomy loops and the Dirac type operator reproduces the structure of a quantized Poisson bracket of general relativity. Finally we give a heuristic argument as to how a natural candidate for a quantized Hamiltonian might emerge from this spectral triple construction. \\ ( http://arxiv.org/abs/0902.4191 , 33kb) %%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%% ------------------------------------------------------------------------------ \\ arXiv:0808.1911 (*cross-listing*) replaced with revised version Wed, 25 Feb 2009 20:02:58 GMT (10kb) Title: Semi-classical central charge in topologically massive gravity Authors: Geoffrey Comp\`ere and St\'ephane Detournay Categories: hep-th gr-qc Comments: major sign mistake in the central charge corrected. Conclusion adapted. Minor typos corrected Journal-ref: Class.Quant.Grav.26:012001,2009 DOI: 10.1088/0264-9381/26/1/012001 \\ ( http://arxiv.org/abs/0808.1911 , 10kb) ------------------------------------------------------------------------------ \\ arXiv:0808.2510 replaced with revised version Wed, 25 Feb 2009 20:55:54 GMT (12kb) Title: Post-Newtonian Approximation in Maxwell-Like Form Authors: Jeff D. Kaplan, David A. Nichols, and Kip S. Thorne Categories: gr-qc Comments: v3: Reformulated in terms of DSX papers. Submitted to Phys Rev D, 6 pages. v2: Added references. Changed our definition of the gravitoelectric field g to match that of Damour, Soffel and Xu (Phys Rev D 43, 3273; "DSX"). We thank Luc Blanchet for calling our attention to DSX and to Blanchet and Damour (Ann. Inst. Henri Poincare, 50, 337) \\ ( http://arxiv.org/abs/0808.2510 , 12kb) ------------------------------------------------------------------------------ \\ arXiv:0809.3036 replaced with revised version Wed, 25 Feb 2009 09:06:30 GMT (64kb) Title: The radiative transfer at second order: a full treatment of the Boltzmann equation with polarization Authors: Cyril Pitrou Categories: gr-qc astro-ph Comments: 62 pages Journal-ref: Class. Quant. Grav. 26 (2009) 065006 DOI: 10.1088/0264-9381/26/6/065006 \\ ( http://arxiv.org/abs/0809.3036 , 64kb) ------------------------------------------------------------------------------ \\ arXiv:0810.1724 replaced with revised version Wed, 25 Feb 2009 07:30:08 GMT (9kb) Title: Active Galactic Nuclei and Transformation of Dark Matter into Visible Matter Authors: A. A. Grib, Yu. V. Pavlov Categories: gr-qc astro-ph Comments: 5 pages, LaTeX; v2: one reference added, published version Journal-ref: Gravit. Cosmology 15 (2009) 44-48 \\ ( http://arxiv.org/abs/0810.1724 , 9kb) ------------------------------------------------------------------------------ \\ arXiv:0811.2230 (*cross-listing*) replaced with revised version Wed, 25 Feb 2009 16:12:45 GMT (427kb) Title: Lorentz Invariance Violation and the Observed Spectrum of Ultrahigh Energy Cosmic Rays Authors: S. T. Scully (JMU) and F. W. Stecker (NASA/GSFC) Categories: astro-ph gr-qc hep-ph Comments: corrected proof version to be published in Astroparticle Physics \\ ( http://arxiv.org/abs/0811.2230 , 427kb) ------------------------------------------------------------------------------ \\ arXiv:0811.2279 replaced with revised version Wed, 25 Feb 2009 05:56:44 GMT (14kb) Title: Entropy bound of local quantum field theory with generalized uncertainty principle Authors: Yong-Wan Kim, Hyung Won Lee, Yun Soo Myung Categories: gr-qc Comments: 11 pages, 1figure, version to appear in PLB \\ ( http://arxiv.org/abs/0811.2279 , 14kb) ------------------------------------------------------------------------------ \\ arXiv:0811.2846 replaced with revised version Wed, 25 Feb 2009 03:14:50 GMT (604kb) Title: Perturbations of Spacetime around a Stationary Rotating Cosmic String Authors: Kouji Ogawa, Hideki Ishihara, Hiroshi Kozaki, and Hiroyuki Nakano Categories: gr-qc Comments: 30 pages, 6 figures; Minor corrections, references added, published version in Physical Review D Report-no: OCU-PHYS 307, AP-GR 64 \\ ( http://arxiv.org/abs/0811.2846 , 604kb) ------------------------------------------------------------------------------ \\ arXiv:0811.3068 replaced with revised version Wed, 25 Feb 2009 12:19:48 GMT (1487kb) Title: Black Holes in the Dilatonic Einstein-Gauss-Bonnet Theory in Various Dimensions II -- Asymptotically AdS Topological Black Holes -- Authors: Zong-Kuan Guo, Nobuyoshi Ohta, Takashi Torii Categories: gr-qc hep-ph hep-th Comments: 24 pages, 8 figures, PTPTeX, typos corrected Report-no: KU-TP 024 Journal-ref: Prog.Theor.Phys.121:253-273,2009 DOI: 10.1143/PTP.121.253 \\ ( http://arxiv.org/abs/0811.3068 , 1487kb) ------------------------------------------------------------------------------ \\ arXiv:0811.4347 replaced with revised version Wed, 25 Feb 2009 15:32:35 GMT (18kb) Title: Gluonic vacuum, q-theory, and the cosmological constant Authors: F.R. Klinkhamer, G.E. Volovik Categories: gr-qc hep-th Comments: 20 pages; final version with additional references to appear in PRD Report-no: KA-TP-30-2008 \\ ( http://arxiv.org/abs/0811.4347 , 18kb) ------------------------------------------------------------------------------ \\ arXiv:0812.0012 replaced with revised version Wed, 25 Feb 2009 17:19:46 GMT (387kb) Title: The n-body problem in General Relativity up to the second post-Newtonian order from perturbative field theory Authors: Yi-Zen Chu Categories: gr-qc astro-ph hep-th Comments: 39 pages. The Mathematica code used in this paper can be found at http://www.stargazing.net/yizen/PN.html Version 2: Slight re-wording of section on removal of accelerations in 2 PN lagrangian; comments added in conclusion; and typographical errors fixed. Article is similar to that published in PRD Journal-ref: Phys. Rev. D. 79, 044031 (2009) \\ ( http://arxiv.org/abs/0812.0012 , 387kb) ------------------------------------------------------------------------------ \\ arXiv:0812.1298 replaced with revised version Wed, 25 Feb 2009 18:57:24 GMT (18kb,D) Title: Einstein-Cartan gravity with Holst term and fermions Authors: Marcin Ka\'zmierczak Categories: gr-qc Comments: 11 pages, changes in Section III, final version, to appear in Phys. Rev. D \\ ( http://arxiv.org/abs/0812.1298 , 18kb) ------------------------------------------------------------------------------ \\ arXiv:0812.4287 (*cross-listing*) replaced with revised version Tue, 24 Feb 2009 21:16:10 GMT (31kb) Title: Membranes at Quantum Criticality Authors: Petr Horava Categories: hep-th cond-mat.mes-hall gr-qc hep-ph Comments: 35 pages; v2: typos corrected; v3: additional typos corrected \\ ( http://arxiv.org/abs/0812.4287 , 31kb) ------------------------------------------------------------------------------ \\ arXiv:0902.0230 replaced with revised version Wed, 25 Feb 2009 10:40:57 GMT (4kb) Title: Hawking temperature and higher order calculations Authors: Bhramar Chatterjee, P. Mitra Categories: gr-qc hep-th Comments: 4 pages; minor changes; comments added about fermions \\ ( http://arxiv.org/abs/0902.0230 , 4kb) ------------------------------------------------------------------------------ \\ arXiv:0902.2360 replaced with revised version Tue, 24 Feb 2009 22:30:44 GMT (18kb) Title: Cylindrical wormholes Authors: Kirill A. Bronnikov, Jos\'e P. S. Lemos Categories: gr-qc Comments: 13 pages, no figures. Substantial changes, a no-go theorem and 2 references added \\ ( http://arxiv.org/abs/0902.2360 , 18kb) %%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%--- For subscribe options to combined physics archives, e-mail To: physics@arXiv.org, Subject: subscribe ----------------------------------------------------------------------------- For help on viewing and making submissions, see http://arXiv.org/help/ For a list of archive mirror sites, see http://arXiv.org/servers.html ----------------------------------------------------------------------------- Third-party submissions cause excessive problems. Author self-submissions are exceedingly preferred. E-mail submissions have been discontinued in favor of better support for Web submissions. See http://arXiv.org/help/uploads