English

The Palatini side of inflationary attractors

General Relativity and Quantum Cosmology 2018-04-20 v2 High Energy Physics - Phenomenology

Abstract

We perform an analysis of models of chaotic inflation where the inflaton field ϕ\phi is coupled non-minimally to gravity via ξϕngμνRμν(Γ),n>0\xi \phi^n g^{\mu\nu}R_{\mu\nu}(\Gamma), n>0. We focus on the Palatini theory of gravity, i.e. the case where the assumptions of the General Relativity are relaxed (that of the connection being the Levi-Civita one) and the gravitational degrees of freedom are encoded not only in the metric but also the connection Γ\Gamma, which is treated as an independent variable. We show that in this case the famous attractor behaviour of simple non-minimally coupled models of inflation is lost. Therefore the attractors are not universal but their existence depends on the underlying theory of gravity in a subtle way. We discuss what this means for chaotic models and their observational consequences.

Keywords

Cite

@article{arxiv.1712.08471,
  title  = {The Palatini side of inflationary attractors},
  author = {Laur Järv and Antonio Racioppi and Tommi Tenkanen},
  journal= {arXiv preprint arXiv:1712.08471},
  year   = {2018}
}

Comments

5 pages, 1 figure. v2: Notation clarified, references and discussion added