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Author Bazeia, D.; Losano, L.; Olmo, G.J.; Rubiera-Garcia, D.; Sanchez-Puente, A.
Title Classical resolution of black hole singularities in arbitrary dimension Type Journal Article
Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 92 Issue 4 Pages 044018 - 15pp
Keywords
Abstract A metric-affine approach is employed to study higher-dimensional modified gravity theories involving different powers and contractions of the Ricci tensor. It is shown that the field equations are always second-order, as opposed to the standard metric approach, where this is only achieved for Lagrangians of the Lovelock type. We point out that this property might have relevant implications for the AdS/CFT correspondence in black hole scenarios. We illustrate these aspects by considering the case of Born-Infeld gravity in d dimensions, where we work out exact solutions for electrovacuum configurations. Our results put forward that black hole singularities in arbitrary dimensions can be cured in a purely classical geometric scenario governed by second-order field equations.
Address [Bazeia, D.; Losano, L.; Olmo, Gonzalo J.] Univ Fed Paraiba, Dept Fis, BR-58051900 Joao Pessoa, Paraiba, Brazil, Email: bazeia@fisica.ufpb.br;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000359443800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (up) 2362
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Author Bazeia, D.; Losano, L.; Menezes, R.; Olmo, G.J.; Rubiera-Garcia, D.
Title Robustness of braneworld scenarios against tensorial perturbations Type Journal Article
Year 2015 Publication Classical and Quantum Gravity Abbreviated Journal Class. Quantum Gravity
Volume 32 Issue 21 Pages 215011 - 10pp
Keywords brane-worlds; tensorial perturbations; metric-affine geometry
Abstract Inspired by the peculiarities of the effective geometry of crystalline structures, we reconsider thick brane scenarios from a metric-affine perspective. We show that for a rather general family of theories of gravity, whose Lagrangian is an arbitrary function of the metric and the Ricci tensor, the background and scalar field equations can be written in first-order form, and tensorial perturbations have a non negative definite spectrum, which makes them stable under linear perturbations regardless of the form of the gravity Lagrangian. We find, in particular, that the tensorial zero modes are exactly the same as predicted by Einstein's theory regardless of the scalar field and gravitational Lagrangians.
Address [Bazeia, D.; Losano, L.; Olmo, Gonzalo J.] Univ Fed Paraiba, Dept Fis, BR-58051900 Joao Pessoa, Paraiba, Brazil, Email: bazeia@fisica.ufpb.br;
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 0264-9381 ISBN Medium
Area Expedition Conference
Notes WOS:000364921200014 Approved no
Is ISI no International Collaboration yes
Call Number IFIC @ pastor @ Serial (up) 2459
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Author Bambi, C.; Cardenas-Avendano, A.; Olmo, G.J.; Rubiera-Garcia, D.
Title Wormholes and nonsingular spacetimes in Palatini f(R) gravity Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 93 Issue 6 Pages 064016 - 8pp
Keywords
Abstract We reconsider the problem of f(R) theories of gravity coupled to Born-Infeld theory of electrodynamics formulated in a Palatini approach, where metric and connection are independent fields. By studying electrovacuum configurations in a static and spherically symmetric spacetime, we find solutions which reduce to their Reissner-Nordstrom counterparts at large distances but undergo important nonperturbative modifications close to the center. Our new analysis reveals that the pointlike singularity is replaced by a finite-size wormhole structure, which provides a geodesically complete and thus nonsingular spacetime, despite the existence of curvature divergences at the wormhole throat. Implications of these results, in particular for the cosmic censorship conjecture, are discussed.
Address [Bambi, Cosimo; Rubiera-Garcia, D.] Fudan Univ, Ctr Field Theory & Particle Phys, 220 Handan Rd, Shanghai 200433, Peoples R China, Email: bambi@fudan.edu.cn;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000371742700005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (up) 2575
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Author Bazeia, D.; Losano, L.; Menezes, R.; Olmo, G.J.; Rubiera-Garcia, D.
Title Thick brane in f(R) gravity with Palatini dynamics Type Journal Article
Year 2015 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 75 Issue Pages 569 - 10pp
Keywords
Abstract This work deals with modified gravity in five dimensional spacetime. We study a thick Palatini f(R) brane, that is, a braneworld scenario described by an anti-de Sitter warped geometry with a single extra dimension of infinite extent, sourced by real scalar field under the Palatini approach, where the metric and the connection are regarded as independent degrees of freedom. We consider a first-order framework which we use to provide exact solutions for the scalar field and warp factor. We also investigate a perturbative scenario such that the Palatini approach is implemented through a Lagrangian f(R)=R+ϵR^n, where the small parameter ϵ controls the deviation from the standard thick brane case.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (up) 2592
Permanent link to this record
 
 
Author Olmo, G.J.; Rubiera-Garcia, D.; Sanchez-Puente, A.
Title Classical resolution of black hole singularities via wormholes Type Journal Article
Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 76 Issue 3 Pages 143 - 6pp
Keywords
Abstract In certain extensions of General Relativity, wormholes generated by spherically symmetric electric fields can resolve black hole singularities without necessarily removing curvature divergences. This is shown by studying geodesic completeness, the behavior of time-like congruences going through the divergent region, and by means of scattering of waves off the wormhole. This provides an example of the logical independence between curvature divergences and space-time singularities, concepts very often identified with each other in the literature.
Address [Olmo, Gonzalo J.; Sanchez-Puente, A.] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000375302500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial (up) 2655
Permanent link to this record