Fourth-order gravity as the inflationary model revisited

Sho Kaneda, Sergei V. Ketov, Natsuki Watanabe

Research School of High-Energy Physics

Research output: Contribution to journal › Article

Abstract

We revisit the old (fourth-order or quadratically generated) gravity model of Starobinsky in four spacetime dimensions, and derive the (inflaton) scalar potential in the equivalent scalartensor gravity model. 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 scalartensor gravity theories.

Original language	English
Pages (from-to)	2753-2762
Number of pages	10
Journal	Modern Physics Letters A
Volume	25
Issue number	32
DOIs	https://doi.org/10.1142/S0217732310033918
Publication status	Published - 20 Oct 2010

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Keywords

Cosmology
inflation
modified gravity
spectral index

ASJC Scopus subject areas

Astronomy and Astrophysics
Nuclear and High Energy Physics

Cite this

Kaneda, S., Ketov, S. V., & Watanabe, N. (2010). Fourth-order gravity as the inflationary model revisited. Modern Physics Letters A, 25(32), 2753-2762. https://doi.org/10.1142/S0217732310033918

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10.1142/S0217732310033918