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Author (up) Arrechea, J.; Delhom, A.; Jimenez-Cano, A.
Title Inconsistencies in four-dimensional Einstein-Gauss-Bonnet gravity Type Journal Article
Year 2021 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume 45 Issue 1 Pages 013107 - 8pp
Keywords alternative theories of gravity; singularities; Einstein-Gauss-Bonnet
Abstract We attempt to clarify several aspects concerning the recently presented four-dimensional Einstein-Gauss-Bonnet gravity. We argue that the limiting procedure outlined in [Phys. Rev. Lett. 124, 081301 (2020)] generally involves ill-defined terms in the four dimensional field equations. Potential ways to circumvent this issue are discussed, alongside remarks regarding specific solutions of the theory. We prove that, although linear perturbations are well behaved around maximally symmetric backgrounds, the equations for second-order perturbations are ill-defined even around a Minkowskian background. Additionally, we perform a detailed analysis of the spherically symmetric solutions and find that the central curvature singularity can be reached within a finite proper time.
Address [Arrechea, Julio] CSIC, Inst Astrofis Andalucia, Granada, Spain, Email: arrechea@iaa.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 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:000606026400001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4676
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Author (up) Bejarano, C.; Delhom, A.; Jimenez-Cano, A.; Olmo, G.J.; Rubiera-Garcia, D.
Title Geometric inequivalence of metric and Palatini formulations of General Relativity Type Journal Article
Year 2020 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 802 Issue Pages 135275 - 4pp
Keywords
Abstract Projective invariance is a symmetry of the Palatini version of General Relativity which is not present in the metric formulation. The fact that the Riemann tensor changes nontrivially under projective transformations implies that, unlike in the usual metric approach, in the Palatini formulation this tensor is subject to a gauge freedom, which allows some ambiguities even in its scalar contractions. In this sense, we show that for the Schwarzschild solution there exists a projective gauge in which the (affine) Kretschmann scalar, K (R beta μnu R alpha beta μnu)-R-alpha, can be set to vanish everywhere. This puts forward that the divergence of curvature scalars may, in some cases, be avoided by a gauge transformation of the connection.
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 Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000515091400031 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4348
Permanent link to this record