|   | 
Details
   web
Records
Author Girones, Z.; Marchetti, A.; Mena, O.; Pena-Garay, C.; Rius, N.
Title Cosmological data analysis of f(R) gravity models Type Journal Article
Year 2010 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 11 Issue 11 Pages 004 - 18pp
Keywords modified gravity; cosmological parameters from LSS
Abstract A class of well-behaved modified gravity models with long enough matter domination epoch and a late-time accelerated expansion is confronted with SNIa, CMB, SDSS, BAO and H(z) galaxy ages data, as well as current measurements of the linear growth of structure. We show that the combination of geometrical probes and growth data exploited here allows to rule out f(R) gravity models, in particular, the logarithmic of curvature model. We also apply solar system tests to the models in agreement with the cosmological data. We find that the exponential of the inverse of the curvature model satisfies all the observational tests considered and we derive the allowed range of parameters. Current data still allows for small deviations of Einstein gravity. Future, high precision growth data, in combination with expansion history data, will be able to distinguish tiny modifications of standard gravity from the Lambda CDM model.
Address [Girones, Z.; Marchetti, A.; Mena, O.; Pena-Garay, C.; Rius, N.] Univ Valencia, CSIC, IFIC, Dept Fis Teor, Valencia 46071, Spain, Email: girones@ific.uv.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes ISI:000284825100004 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ elepoucu @ Serial 315
Permanent link to this record
 

 
Author Olmo, G.J.
Title Palatini actions and quantum gravity phenomenology Type Journal Article
Year 2011 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 10 Issue 10 Pages 018 - 15pp
Keywords quantum gravity phenomenology; cosmic singularity
Abstract We show that an invariant an universal length scale can be consistently introduced in a generally covariant theory through the gravitational sector using the Palatini approach. The resulting theory is able to capture different aspects of quantum gravity phenomenology in a single framework. In particular, it is found that in this theory field excitations propagating with different energy-densities perceive different background metrics, which is a fundamental characteristic of the DSR and Rainbow Gravity approaches. We illustrate these properties with a particular gravitational model and explicitly show how the soccer ball problem is avoided in this framework. The isotropic and anisotropic cosmologies of this model also avoid the big bang singularity by means of a big bounce.
Address [Olmo, GJ] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000296767600018 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ elepoucu @ Serial 816
Permanent link to this record
 

 
Author Olmo, G.J.
Title Palatini approach to modified gravity: f(R) theories and beyond Type Journal Article
Year 2011 Publication International Journal of Modern Physics D Abbreviated Journal Int. J. Mod. Phys. D
Volume 20 Issue 4 Pages 413-462
Keywords Palatini formalism; modified gravity; cosmic speed-up; dark energy; dark matter; MOND; quantum gravity phenomenology; Hamiltonian formulation; stellar structure; Cauchy problem; solar system tests
Abstract We review the recent literature on modified theories of gravity in the Palatini approach. After discussing the motivations that lead to consider alternatives to Einstein's theory and to treat the metric and the connection as independent objects, we review several topics that have been recently studied within this framework. In particular, we provide an in-depth analysis of the cosmic speed-up problem, laboratory and solar system tests, the structure of stellar objects, the Cauchy problem, and bouncing cosmologies. We also discuss the importance of going beyond the f(R) models to capture other phenomenological aspects related with dark matter/energy and quantum gravity.
Address [Olmo, Gonzalo J.] Univ Valencia CSIC, Dept Fis Teor, Valencia, Spain, Email: gonzalo.olmo@uv.es
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0218-2718 ISBN Medium
Area Expedition Conference
Notes WOS:000290228200001 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 961
Permanent link to this record
 

 
Author Galli, P.; Ortin, T.; Perz, J.; Shahbazi, C.S.
Title From supersymmetric to non-supersymmetric black holes Type Journal Article
Year 2012 Publication Fortschritte der Physik-Progress of Physics Abbreviated Journal Fortschritte Phys.-Prog. Phys.
Volume 60 Issue 9-10 Pages 1026-1029
Keywords Black holes; supergravity
Abstract Methods similar to those used for obtaining supersymmetric black hole solutions can be employed to find also non-supersymmetric solutions. We briefly review some of them, with the emphasis on the non-extremal deformation ansatz of [1].
Address [Ortin, Tomas; Perz, Jan; Shahbazi, C. S.] Inst Fis Teor UAM CSIC, Madrid 28049, Spain, Email: Pietro.Galli@ific.uv.es;
Corporate Author Thesis
Publisher Wiley-V C H Verlag Gmbh Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0015-8208 ISBN Medium
Area Expedition Conference
Notes WOS:000308301500012 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 1151
Permanent link to this record
 

 
Author Olmo, G.J.; Rubiera-Garcia, D.
Title Nonsingular Charged Black Holes A La Palatini Type Journal Article
Year 2012 Publication International Journal of Modern Physics D Abbreviated Journal Int. J. Mod. Phys. D
Volume 21 Issue 8 Pages 1250067 - 6pp
Keywords Extended theories of gravity; Palatini formalism; Planck scale
Abstract We argue that the quantum nature of matter and gravity should lead to a discretization of the allowed states of the matter confined in the interior of black holes. To support and illustrate this idea, we consider a quadratic extension of general relativity (GR) formulated a la Palatini and show that nonrotating, electrically charged black holes develop a compact core at the Planck density which is nonsingular if the mass spectrum satisfies a certain discreteness condition. We also find that the area of the core is proportional to the number of charges times the Planck area.
Address [Olmo, Gonzalo J.] Univ Valencia, CSIC, Dept Fis Teor, Fac Fis, E-46100 Valencia, Spain
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0218-2718 ISBN Medium
Area Expedition Conference
Notes WOS:000308497500002 Approved no
Is ISI yes International Collaboration (up) no
Call Number IFIC @ pastor @ Serial 1154
Permanent link to this record