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Author |
Bazeia, D.; Losano, L.; Menezes, R.; Olmo, G.J.; Rubiera-Garcia, D. |
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Title |
Robustness of braneworld scenarios against tensorial perturbations |
Type |
Journal Article |
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Year |
2015 |
Publication  |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
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Volume |
32 |
Issue |
21 |
Pages |
215011 - 10pp |
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Keywords |
brane-worlds; tensorial perturbations; metric-affine geometry |
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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. |
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Address |
[Bazeia, D.; Losano, L.; Olmo, Gonzalo J.] Univ Fed Paraiba, Dept Fis, BR-58051900 Joao Pessoa, Paraiba, Brazil, Email: bazeia@fisica.ufpb.br; |
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Publisher |
Iop Publishing Ltd |
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English |
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ISSN |
0264-9381 |
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Notes |
WOS:000364921200014 |
Approved |
no |
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Is ISI |
no |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2459 |
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Author |
Olmo, G.J.; Rubiera-Garcia, D.; Sanchez-Puente, A. |
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Title |
Impact of curvature divergences on physical observers in a wormhole space-time with horizons |
Type |
Journal Article |
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Year |
2016 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
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Volume |
33 |
Issue |
11 |
Pages |
115007 - 12pp |
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Keywords |
Singularities; black holes; metric-affine geometry |
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Abstract |
The impact of curvature divergences on physical observers in a black hole space-time, which, nonetheless, is geodesically complete is investigated. This space-time is an exact solution of certain extensions of general relativity coupled to Maxwell's electrodynamics and, roughly speaking, consists of two Reissner-Nordstrom (or Schwarzschild or Minkowski) geometries connected by a spherical wormhole near the center. We find that, despite the existence of infinite tidal forces, causal contact is never lost among the elements making up the observer. This suggests that curvature divergences may not be as pathological as traditionally thought. |
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Address |
[Olmo, Gonzalo J.; Sanchez-Puente, A.] Univ Valencia, CSIC, Ctr Mixto, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es; |
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Publisher |
Iop Publishing Ltd |
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Language |
English |
Summary Language |
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Abbreviated Series Title |
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ISSN |
0264-9381 |
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Conference |
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Notes |
WOS:000377442000010 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2728 |
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Author |
Bazeia, D.; Losano, L.; Olmo, G.J.; Rubiera-Garcia, D. |
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Title |
Geodesically complete BTZ-type solutions of 2+1 Born-Infeld gravity |
Type |
Journal Article |
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Year |
2017 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
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Volume |
34 |
Issue |
4 |
Pages |
045006 - 21pp |
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Keywords |
Born-Infeld gravity; BTZ; wormholes; nonsingular solutions; geodesic completeness |
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Abstract |
We study Born-Infeld gravity coupled to a static, non-rotating electric field in 2 + 1 dimensions and find exact analytical solutions. Two families of such solutions represent geodesically complete, and hence nonsingular, spacetimes. Another family represents a point-like charge with a singularity at the center. Despite the absence of rotation, these solutions resemble the charged, rotating BTZ solution of general relativity but with a richer structure in terms of horizons. The nonsingular character of the first two families turn out to be attached to the emergence of a wormhole structure on their innermost region. This seems to be a generic prediction of extensions of general relativity formulated in metric-affine (or Palatini) spaces, where metric and connection are regarded as independent degrees of freedom. |
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Address |
[Bazeia, D.; Losano, L.; Olmo, Gonzalo J.] Univ Fed Paraiba, Dept Fis, BR-58051900 Joao Pessoa, Paraiba, Brazil, Email: bazeia@fisica.ufpb.br; |
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Corporate Author |
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Publisher |
Iop Publishing Ltd |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0264-9381 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000395398800002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3013 |
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Author |
Olmo, G.J.; Rubiera-Garcia, D.; Sanchez-Puente, A. |
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Title |
Accelerated observers and the notion of singular spacetime |
Type |
Journal Article |
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Year |
2018 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
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Volume |
35 |
Issue |
5 |
Pages |
055010 - 18pp |
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Keywords |
general relativity; geodesic behaviour; black holes; spacetime singularities; modified theories of gravity |
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Abstract |
Geodesic completeness is typically regarded as a basic criterion to determine whether a given spacetime is regular or singular. However, the principle of general covariance does not privilege any family of observers over the others and, therefore, observers with arbitrary motions should be able to provide a complete physical description of the world. This suggests that in a regular spacetime, all physically acceptable observers should have complete paths. In this work we explore this idea by studying the motion of accelerated observers in spherically symmetric spacetimes and illustrate it by considering two geodesically complete black hole spacetimes recently described in the literature. We show that for bound and locally unbound accelerations, the paths of accelerated test particles are complete, providing further support to the regularity of such spacetimes. |
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Address |
[Olmo, Gonzalo J.; Sanchez-Puente, Antonio] Univ Valencia, Dept Fis Teor, CSIC, Ctr Mixto, E-46100 Valencia, Spain, Email: gonzalo.olmo@uv.es; |
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Corporate Author |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0264-9381 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000424042100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3473 |
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Author |
Olmo, G.J.; Rubiera-Garcia, D. |
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Title |
Junction conditions in Palatini f(R) gravity |
Type |
Journal Article |
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Year |
2020 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
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Volume |
37 |
Issue |
21 |
Pages |
215002 - 11pp |
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Keywords |
f(R) gravity; junction conditions; Palatini approach; stellar structure |
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Abstract |
We work out the junction conditions for f(R) gravity formulated in metric-affine (Palatini) spaces using a tensor distributional approach. These conditions are needed for building consistent models of gravitating bodies with an interior and exterior regions matched at some hypersurface. Some of these conditions depart from the standard Darmois-Israel ones of general relativity and from their metric f(R) counterparts. In particular, we find that the trace of the stress-energy momentum tensor in the bulk must be continuous across the matching hypersurface, though its normal derivative need not to. We illustrate the relevance of these conditions by considering the properties of stellar surfaces in polytropic models, showing that the range of equations of state with potentially pathological effects is shifted beyond the domain of physical interest. This confirms, in particular, that neutron stars and white dwarfs can be safely modelled within the Palatini f(R) framework. |
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Address |
[Olmo, Gonzalo J.] Univ Valencia, Ctr Mixto Univ Valencia, CSIC, Dept Fis Teor, Valencia 46100, Spain, Email: gonzalo.olmo@uv.es; |
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Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0264-9381 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000575326000001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4555 |
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