Chaotic inflation in modified gravitational theories

Antonio De Felice, Shinji Tsujikawa, Joseph Elliston, Reza Tavakol

研究成果: Review article査読

41 被引用数 (Scopus)

抄録

We study chaotic inflation in the context of modified gravitational theories. Our analysis covers models based on (i) a field coupling ω(φ) with the kinetic energy X = -(1/2)gμν μφνφ and a nonmimimal coupling ζφ2R/2 with a Ricci scalar R, (ii) Brans-Dicke (BD) theories, (iii) Gauss-Bonnet (GB) gravity, and (iv) gravity with a Galileon correction. Dilatonic coupling with the kinetic energy and/or negative nonminimal coupling are shown to lead to compatibility with observations of the Cosmic Microwave Background (CMB) temperature anisotropies for the self-coupling inflaton potential V(φ) = λφ4/4. BD theory with a quadratic inflaton potential, which covers Starobinsky's f(R) model f(R) = R+R2/(6M2) with the BD parameter ωBD = 0, gives rise to a smaller tensor-to-scalar ratio for decreasing ωBD. In the presence of a GB term coupled to the field φ, we express the scalar/tensor spectral indices ns and nt as well as the tensor-to-scalar ratio r in terms of two slow-roll parameters and place bounds on the strength of the GB coupling from the joint data analysis of WMAP 7yr combined with other observations. We also study the Galileon-like self-interaction Φ(φ)Xφ with exponential coupling Φ(φ)e μφ. Using a CMB likelihood analysis we put bounds on the strength of the Galileon coupling and show that the self coupling potential can in fact be made compatible with observations in the presence of the exponential coupling with μ > 0.

本文言語English
論文番号021
ジャーナルJournal of Cosmology and Astroparticle Physics
2011
8
DOI
出版ステータスPublished - 2011 8
外部発表はい

ASJC Scopus subject areas

  • Astronomy and Astrophysics

フィンガープリント 「Chaotic inflation in modified gravitational theories」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル