2006/09/28 by Yi Ling
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #gr-qc
paper · pdf · doi:10.1088/1475-7516/2007/08/017
published as JCAP 0708:017,2007 · 5 pages
arxiv created 2006/09/28 · openalex publication_date 2007/08/20 · arxiv updated 2009/12/01 · openalex created_date 2020/07/02 · openalex updated_date 2026/07/30
The formalism of rainbow gravity is studied in a cosmological setting. We consider the very early universe which is radiation dominated. A novel treatment in our paper is looking for an 'averaged' cosmological metric probed by radiation particles themselves. Taking their cosmological evolution into account, we derive the modified Friedmann–Robertson–Walker (FRW) equations, which is a generalization of the solution presented by Magueijo and Smolin. On the basis of this phenomenological cosmological model we argue that the spacetime curvature has an upper bound such that the cosmological singularity is absent. These modified FRW equations can be treated as effective equations in the semi-classical framework of quantum gravity and its analogy with the one recently proposed in loop quantum cosmology is also discussed.