English

Fourth-order gravity as the inflationary model revisited

High Energy Physics - Theory 2010-12-09 v5 Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology

Abstract

We revisit the old (fourth-order or quadratically generated) gravity model of Starobinsky in four space-time dimensions, and derive the (inflaton) scalar potential in the equivalent scalar-tensor gravity model via a Legendre-Weyl transform. The inflaton scalar potential is used to compute the (CMB) observables of inflation associated with curvature perturbations (namely, the scalar and tensor spectral indices, and the tensor-to-scalar ratio), including the new next-to-leading-order terms with respect to the inverse number of e-foldings. The results are compared to the recent (WMAP5) experimental bounds. We confirm both mathematical and physical equivalence between f(R) gravity theories and the corresponding scalar-tensor gravity theories.

Keywords

Cite

@article{arxiv.1001.5118,
  title  = {Fourth-order gravity as the inflationary model revisited},
  author = {S. Kaneda and S. V. Ketov and N. Watanabe},
  journal= {arXiv preprint arXiv:1001.5118},
  year   = {2010}
}

Comments

10 pages, 1 figure, 1 table, LaTeX; few comments added, style improved, references added and updated