Cosmological scaling solutions for multiple scalar fields

Takeshi Chiba, Antonio De Felice, Shinji Tsujikawa

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The general k-essence Lagrangian for the existence of cosmological scaling solutions is derived in the presence of multiple scalar fields coupled to a barotropic perfect fluid. In addition to the scaling fixed point associated with the dynamics during the radiation and matter eras, we also obtain a scalar-field dominated solution relevant to dark energy and discuss the stability of them in the two-field setup. We apply our general results to a model of two canonical fields with coupled exponential potentials arising in string theory. Depending on model parameters and initial conditions, we show that the scaling matter-dominated epochs followed by an attractor with cosmic acceleration can be realized with/without the couplings to scalar fields. The different types of scaling solutions can be distinguished from each other by the evolution of the dark energy equation of state from high redshifts to today.

Original languageEnglish
Article number023516
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume90
Issue number2
DOIs
Publication statusPublished - 2014 Jul 10

ASJC Scopus subject areas

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

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