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Author Bejarano, C.; Olmo, G.J.; Rubiera-Garcia, D.
Title What is a singular black hole beyond general relativity? Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 95 Issue 6 Pages 064043 - 18pp
Keywords
Abstract Exploring the characterization of singular black hole spacetimes, we study the relation between energy density, curvature invariants, and geodesic completeness using a quadratic f(R) gravity theory coupled to an anisotropic fluid. Working in a metric-affine approach, our models and solutions represent minimal extensions of general relativity (GR) in the sense that they rapidly recover the usual Reissner-Nordstrm solution from near the inner horizon outwards. The anisotropic fluid helps modify only the innermost geometry. Depending on the values and signs of two parameters on the gravitational and matter sectors, a breakdown of the correlations between the finiteness/ divergence of the energy density, the behavior of curvature invariants, and the (in) completeness of geodesics is obtained. We find a variety of configurations with and without wormholes, a case with a de Sitter interior, solutions that mimic nonlinear models of electrodynamics coupled to GR, and configurations with up to four horizons. Our results raise questions regarding what infinities, if any, a quantum version of these theories should regularize.
Address [Bejarano, Cecilia] UBA, CONICET, IAFE, Casilla Correo 67,Sucursal 28, RA-1428 Buenos Aires, DF, Argentina, Email: cbejarano@iafe.uba.ar;
Corporate Author Thesis
Publisher (up) 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:000399146000007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3046
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Author Menchon, C.C.; Olmo, G.J.; Rubiera-Garcia, D.
Title Nonsingular black holes, wormholes, and de Sitter cores from anisotropic fluids Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 96 Issue 10 Pages 104028 - 16pp
Keywords
Abstract We study Born-Infeld gravity coupled to an anisotropic fluid in a static, spherically symmetric background. The free function characterizing the fluid is selected on the following grounds: i) recovery of the Reissner-Nordstrom solution of General Relativity at large distances, ii) fulfillment of classical energy conditions, and iii) inclusion of models of nonlinear electrodynamics as particular examples. Four branches of solutions are obtained, depending on the signs of two parameters on the gravity and matter sectors. On each branch, we discuss in detail the modifications on the innermost region of the corresponding solutions, which provides a plethora of configurations, including nonsingular black holes and naked objects, wormholes, and de Sitter cores. The regular character of these configurations is discussed according to the completeness of geodesics and the behavior of curvature scalars.
Address [Menchon, Cintia C.; Olmo, Gonzalo J.] Univ Valencia, Ctr Mixto Univ Valencia CSIC, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@uv.es;
Corporate Author Thesis
Publisher (up) 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:000415600400009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3369
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Author Afonso, V.I.; Olmo, G.J.; Rubiera-Garcia, D.
Title Mapping Ricci-based theories of gravity Into general relativity Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 97 Issue 2 Pages 021503 - 6pp
Keywords
Abstract We show that the space of solutions of a wide class of Ricci-based metric-affine theories of gravity can be put into correspondence with the space of solutions of general relativity (GR). This allows us to use well-established methods and results from GR to explore new gravitational physics beyond it.
Address [Afonso, V. I.] Univ Fed Campina Grande, Unidade Acad Fis, BR-58109970 Campina Grande, PB, Brazil, Email: viafonso@df.ufcg.edu.br;
Corporate Author Thesis
Publisher (up) 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:000423656900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3467
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Author Barrientos, E.; Lobo, F.S.N.; Mendoza, S.; Olmo, G.J.; Rubiera-Garcia, D.
Title Metric-affine f(R,T) theories of gravity and their applications Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 97 Issue 10 Pages 104041 - 10pp
Keywords
Abstract We study f (R, T) theories of gravity, where T is the trace of the energy-momentum tensor T-mu v, with independent metric and affine connection (metric-affine theories). We find that the resulting field equations share a close resemblance with their metric-affine f(R) relatives once an effective energy-momentum tensor is introduced. As a result, the metric field equations are second-order and no new propagating degrees of freedom arise as compared to GR, which contrasts with the metric formulation of these theories, where a dynamical scalar degree of freedom is present. Analogously to its metric counterpart, the field equations impose the nonconservation of the energy-momentum tensor, which implies nongeodesic motion arid consequently leads to the appearance of an extra force. The weak field limit leads to a modified Poisson equation formally identical to that found in Eddington-inspired Born-Infeld gravity. Furthermore, the coupling of these gravity theories to perfect fluids, electromagnetic, and scalar fields, and their potential applications arc discussed.
Address [Barrientos, E.; Mendoza, S.] Univ Nacl Autonoma Mexico, Inst Astron, AP 70-264, Ciudad De Mexico 04510, Mexico, Email: ebarrientos@astro.unam.mx;
Corporate Author Thesis
Publisher (up) 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:000433036500004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3585
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Author Bazeia, D.; Marques, M.A.; Olmo, G.J.
Title Small and hollow magnetic monopoles Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 2 Pages 025017 - 8pp
Keywords
Abstract We deal with the presence of magnetic monopoles in a non-Abelian model that generalizes the standard 't Hooft-Polyakov model in three spatial dimensions. We investigate the energy density of the static and spherically symmetric solutions to find first order differential equations that solve the equations of motion. The system is further studied and two distinct classes of solutions are obtained, one that can also be described by analytical solutions and is called a small monopole, since it is significantly smaller than the standard 't Hooft-Polyakov monopole. The other type of structure is the hollow monopole, since the energy density is endowed with a hole at its core. The hollow monopole can be smaller or larger than the standard monopole, depending on the value of the parameter that controls the magnetic permeability of the model.
Address [Bazeia, D.; Marques, M. A.; Olmo, Gonzalo J.] Univ Fed Paraiba, Dept Fis, BR-58051970 Joao Pessoa, Paraiba, Brazil
Corporate Author Thesis
Publisher (up) 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:000439545000007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3672
Permanent link to this record