2006/06/19 by Martin Bojowald, Mikhail Kagan · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.74.044033
published as Phys.Rev. D74 (2006) 044033 · 10 pages, 4 figures
arxiv created 2006/06/19 · openalex publication_date 2006/08/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Nonminimal actions with matter represented by a scalar field coupled to gravity are considered in the context of a homogeneous and isotropic universe. The coupling is of the form \ensuremath-(1)/(2)\ensuremathξ\ensuremathφ2R. The possibility of successful inflation is investigated taking into account features of loop cosmology. For that end a conformal transformation is performed. That brings the theory into the standard minimally coupled form (Einstein frame) with some effective field and its potential. Both analytical and numerical estimates show that a negative coupling constant is preferable for successful inflation. Moreover, provided fixed initial conditions, larger |\ensuremathξ| leads to a greater number of e-folds. The latter is obtained for a reasonable range of initial conditions and the coupling parameter and indicates a possibility for successful inflation.