English

Inflation in a conformally-invariant two-scalar-field theory with an extra $R^2$ term

High Energy Physics - Theory 2015-07-10 v2 Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Phenomenology

Abstract

We explore inflationary cosmology in a theory where there are two scalar fields which non-minimally couple to the Ricci scalar and an additional R2R^2 term, which breaks the conformal invariance. Particularly, we investigate the slow-roll inflation in the case of one dynamical scalar field and that of two dynamical scalar fields. It is explicitly demonstrated that the spectral index of scalar mode of the density perturbations and the tensor-to-scalar ratio can be consistent with the observations acquired by the recent Planck satellite. The graceful exit from the inflationary stage is achieved as in convenient R2R^2 gravity. We also propose the generalization of the model under discussion with three scalar fields.

Keywords

Cite

@article{arxiv.1505.00854,
  title  = {Inflation in a conformally-invariant two-scalar-field theory with an extra $R^2$ term},
  author = {Kazuharu Bamba and Sergei D. Odintsov and Petr V. Tretyakov},
  journal= {arXiv preprint arXiv:1505.00854},
  year   = {2015}
}

Comments

18 pages, 4 figures, version accepted for publication in European Physical Journal C