2006/01/31 by S. Nojiri, SHIN'ICHI NOJIRI, S. D. Odintsov +1 · 5 citations
Computer Science · Physics and Astronomy · #Black Holes and Theoretical Physics #Computational Physics and Python Applications #Cosmology and Gravitation Theories #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1142/s0219887807001928
published as ECONF C0602061:06,2006; Int.J.Geom.Meth.Mod.Phys.4:115-146,2007 · LaTeX file, 21 pages, references are added, lectures for 42 Karpacz Winter School on Theor Physics
arxiv created 2006/03/31 · openalex publication_date 2007/02/01 · arxiv updated 2009/12/01 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/03
We review various modified gravities considered as gravitational alternative for dark energy. Specifically, we consider the versions of f(R), f(G) or f(R, G) gravity, model with non-linear gravitational coupling or string-inspired model with Gauss-Bonnet-dilaton coupling in the late universe where they lead to cosmic speed-up. It is shown that some of such theories may pass the Solar System tests. On the same time, it is demonstrated that they have quite rich cosmological structure: they may naturally describe the effective (cosmological constant, quintessence or phantom) late-time era with a possible transition from decceleration to acceleration thanks to gravitational terms which increase with scalar curvature decrease. The possibility to explain the coincidence problem as the manifestation of the universe expansion in such models is mentioned. The late (phantom or quintessence) universe filled with dark fluid with inhomogeneous equation of state (where inhomogeneous terms are originated from the modified gravity) is also described.