Generalized Brans-Dicke theories

Antonio De Felice, Shinji Tsujikawa

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

In Brans-Dicke theory a non-linear self interaction of a scalar field Ø allows a possibility of realizing the late-time cosmic acceleration, while recovering the General Relativistic behavior at early cosmological epochs. We extend this to more general modified gravitational theories in which a de Sitter solution for dark energy exists without using a field potential. We derive a condition for the stability of the de Sitter point and study the background cosmological dynamics of such theories. We also restrict the allowed region of model parameters from the demand for the avoidance of ghosts and instabilities. A peculiar evolution of the field propagation speed allows us to distinguish those theories from the ACDM model.

Original languageEnglish
Article number024
JournalJournal of Cosmology and Astroparticle Physics
Volume2010
Issue number7
DOIs
Publication statusPublished - 2010 Jul
Externally publishedYes

Keywords

  • Cosmological perturbation theory
  • Dark energy theory
  • Modified gravity

ASJC Scopus subject areas

  • Astronomy and Astrophysics

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