Gödel-type solutions within the f(R,Q) gravity

Abstract

In this paper, we deal with the $f(R,Q)$ gravity whose action depends, besides of the scalar curvature $R$, on the higher-derivative invariant $Q=R_{\mu \nu }{R}^{\mu \nu }$. In order to compare this theory with the usual General Relativity (GR), we verify the consistency of Gödel-type solutions within the $f(R,Q)$ gravity and discuss the related causality issues. Explicitly, we show that in the $f(R,Q)$ gravity there are new Gödel-type completely causal solutions having no analogue in the general relativity. In particular, a remarkable Gödel-type solution corresponding to the conformally flat space and maximally symmetric for physically well-motivated matter sources, with no necessity of cosmological constant, has been considered. We demonstrate that, in contrast to GR framework, $f(R,Q)$ gravity supports new vacuum solutions with the requirement for the cosmological constant to be non-zero. Finally, causal solutions are obtained for a particular choice $f(R,Q)=R+\alpha R^2+\beta Q$.

18 pages, version accepted to Phys. Rev. D

References in corpus (8)

• Extended Theories of Gravity and their Cosmological and Astrophysical Applications
• Black Holes in Higher-Derivative Gravity
• What Do We Know About Lorentz Invariance?
• Bouncing Cosmologies in Palatini $f(R)$ Gravity
• Gödel-type universes in f(R) gravity
• Gödel-type universes in Palatini f(R) gravity
• The Gödel solution in the modified gravity
• On the causality aspects of the dynamical Chern-Simons modified gravity

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• Chronons in M-theory and F-theory