Inflationary gravitational waves in the effective field theory of modified gravity

Antonio De Felice, Shinji Tsujikawa

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

In the approach of the effective field theory of modified gravity, we derive the second-order action and the equation of motion for tensor perturbations on the flat isotropic cosmological background. This analysis accommodates a wide range of gravitational theories including Horndeski theories, its generalization, and the theories with spatial derivatives higher than second order (e.g., Hořava-Lifshitz gravity). We obtain the inflationary power spectrum of tensor modes by taking into account corrections induced by higher-order spatial derivatives and slow-roll corrections to the de Sitter background. We also show that the leading-order spectrum in concrete modified gravitational theories can be mapped on to that in General Relativity under a disformal transformation. Our general formula will be useful to constrain inflationary models from the future precise measurement of the B-mode polarization in the cosmic microwave background.

Original languageEnglish
Article number103506
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume91
Issue number10
DOIs
Publication statusPublished - 2015 May 11
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)

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