2003/09/30 by Xin-He Meng, Peng Wang · 14 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #hep-th
paper · pdf · doi:10.1016/j.physletb.2004.01.052
published as Phys.Lett. B584 (2004) 1-7 · 11 pages, 2 figures, minor corrections to match the published version
arxiv created 2004/02/02 · openalex publication_date 2004/02/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/02
Recently, corrections to the standard Einstein–Hilbert action are proposed to explain the current cosmic acceleration instead of introducing dark energy. We discuss the Palatini formulation of the modified gravity with a lnR term suggested by Nojiri and Odintsov. We show that in the Palatini formulation, the lnR gravity can drive a current exponential accelerated expansion and it reduces to the standard Friedmann evolution for high redshift region. We also discuss the equivalent scalar–tensor formulation of the theory. We indicate that the lnR gravity may still have a conflict with electron–electron scattering experiment which stimulates us to pursue a more fundamental theory which can give the lnR gravity as an effective theory. Finally, we discuss a problem faced with the extension of the lnR gravity by adding Rm terms.