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Author Izadi, A.; Shacker, S.S.; Olmo, G.J.; Banerjee, R.
Title Observational effects of varying speed of light in quadratic gravity cosmological models Type Journal Article
Year 2018 Publication International Journal of Geometric Methods in Modern Physics Abbreviated Journal Int. J. Geom. Methods Mod. Phys.
Volume 15 Issue 5 Pages 1850084 - 16pp
Keywords Palatini formalism; modified gravity; causal structure constant; varying speed of light
Abstract We study different manifestations of the speed of light in theories of gravity where metric and connection are regarded as independent fields. We find that for a generic gravity theory in a frame with locally vanishing affine connection, the usual degeneracy between different manifestations of the speed of light is broken. In particular, the space-time causal structure constant (c(ST)) may become variable in that local frame. For theories of the form f(R, R-mu nu R-mu nu), this variation in c(ST) has an impact on the definition of the luminosity distance (and distance modulus), which can be used to confront the predictions of particular models against Supernovae type Ia (SN Ia) data. We carry out this test for a quadratic gravity model without cosmological constant assuming (i) a constant speed of light and (ii) a varying speed of light (VSL), and find that the latter scenario is favored by the data.
Address [Izadi, Azam] Khajeh Nasir Toosi Univ Technol, Dept Phys, Tehran, Iran, Email: aizadi@kntu.ac.ir;
Corporate Author Thesis
Publisher (down) 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 0219-8878 ISBN Medium
Area Expedition Conference
Notes WOS:000429106400016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3553
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Author Olmo, G.J.; Rubiera-Garcia, D.
Title Some recent results on Ricci-based gravity theories Type Journal Article
Year 2022 Publication International Journal of Modern Physics D Abbreviated Journal Int. J. Mod. Phys. D
Volume 31 Issue Pages 2240012 - 15pp
Keywords Metric-affine gravity; scalar fields; stellar models; junction conditions; compact objects
Abstract In this paper, metric-afline theories in which the gravity Lagrangian is built using (projectively invariant) contractions of the Ricci tensor with itself and with the metric (Ricci-based gravity theories, or RBGs for short) are reviewed. The goal is to provide a contextualized and coherent presentation of some recent results. In particular, we focus on the correspondence that exists between the field equations of these theories and those of general relativity, and comment on how this can be used to build new solutions of physical interest. We also discuss the formalism of junction conditions in the f (R) case, and provide a brief summary on current experimental and observational bounds on model parameters.
Address [Olmo, Gonzalo J.] Univ Valencia, CSIC, Ctr Mixto, Dept Fis Teor, Valencia 46100, Spain, Email: gonzalo.olmo@uv.es;
Corporate Author Thesis
Publisher (down) 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:000848888900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5350
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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 (down) 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 no
Call Number IFIC @ pastor @ Serial 1151
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Author Galli, P.; Goldstein, K.; Katmadas, S.; Perz, J.
Title First-order flows and stabilisation equations for non-BPS extremal black holes Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 070 - 28pp
Keywords Black Holes in String Theory; Supergravity Models
Abstract We derive a generalised form of flow equations for extremal static and rotating non-BPS black holes in four-dimensional ungauged N = 2 supergravity coupled to vector multiplets. For particular charge vectors, we give stabilisation equations for the scalars, analogous to the BPS case, describing full known solutions. Based on this, we propose a generic ansatz for the stabilisation equations, which surprisingly includes ratios of harmonic functions.
Address [Galli, P] Univ Valencia, Dept Fis Teor, E-46100 Burjassot, Valencia, Spain, Email: Pietro.Galli@ific.uv.es
Corporate Author Thesis
Publisher (down) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000293136500070 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 746
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Author Galli, P.; Goldstein, K.; Perz, J.
Title On anharmonic stabilisation equations for black holes Type Journal Article
Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 036 - 7pp
Keywords Black Holes in String Theory; Supergravity Models
Abstract We investigate the stabilisation equations for sufficiently general, yet regular, extremal (supersymmetric and non-supersymmetric) and non-extremal black holes in four-dimensional N = 2 supergravity using both the H-FGK approach and a generalisation of Denef's formalism. By an explicit calculation we demonstrate that the equations necessarily contain an anharmonic part, even in the static, spherically symmetric and asymptotically flat case.
Address Univ Valencia, Dept Fis Teor, E-46100 Burjassot, Valencia, Spain, Email: Pietro.Galli@ific.uv.es;
Corporate Author Thesis
Publisher (down) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000317521200036 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1417
Permanent link to this record