2020/05/11 by Gaurav Narain, Hai-Qing Zhang, Narain, Gaurav +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.2005.05183
openalex publication_date 2020/05/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this short paper we investigate any non-trivial effect the novel Gauss-Bonnet gravity may give rise in the cosmic evolution of the Universe in four spacetime dimensions. We start by considering a generic Friedmann-Lemaître-Robertson-Walker (FLRW) metric respecting homogeneity and isotropicity in arbitrary space-time dimension D. The metric depends on two functions: scale factor and lapse. Plugging this metric in novel Einstein-Gauss-Bonnet (EGB) gravity action, doing an integration by parts and then take the limit of D→4 give us a dynamical action in four spacetime dimensions for scale factor and lapse. The peculiar rescaling of Gauss-Bonnet coupling by factor of D-4 results in a non-trivial contribution in the action of the theory. In this paper we study this action. We investigate the dynamics of scale-factor and behavior of lapse in an empty Universe (no matter). Due to complexity of the problem we study the theory to first order in Gauss-Bonnet coupling and solve system of equation to the first order. We compute the first order correction to the on-shell action of the empty Universe and find that its sign is opposite of the leading order part. We discuss it consequences.