2016/03/31 by Alvaro de la Cruz-Dombriz, Emilio Elizalde, Sergei D. Odintsov +1
Physics and Astronomy · #gr-qc #hep-th
paper · pdf · doi:10.1088/1475-7516/2016/05/060
published as JCAP 05 (2016) 060 · 24 pages, 1 figure, minor changes, version matching published version, conclusions unchanged. arXiv admin note: text overlap with arXiv:1411.1636 by other authors
arxiv created 2016/05/25 · arxiv updated 2016/06/09
We discuss the soundness of inflationary scenarios in theories beyond the Starobinsky model, namely a class of theories described by arbitrary functions of the Ricci scalar and the K-essence field. We discuss the pathologies associated with higher-order equations of motion which will be shown to constrain the stability of this class of theories. We provide a general framework to calculate the slow-roll parameters and the corresponding mappings to the theory parameters. For paradigmatic gravitational models within the class of theories under consideration we illustrate the power of the Planck/Bicep2 latest results to constrain such gravitational Lagrangians. Finally, bounds for potential deviations from Starobinsky-like inflation are derived.