Constraining α-attractor models from reheating

Abstract

In this paper, we eliminate the parameters originally present in models of inflation of the [Formula: see text]-attractor type in favor of the scalar spectral index [Formula: see text] and the tensor-to-scalar ratio [Formula: see text]. We then write expressions for the number of [Formula: see text]-folds during reheating [Formula: see text]. By imposing reasonable conditions on [Formula: see text], we can restrict [Formula: see text] and [Formula: see text] and in turn, we use these constraints in order to find bounds for cosmological quantities of interest such as the number of [Formula: see text]-folds during inflation and the radiation dominated eras, as well as for the reheating temperature and the running index. The minimum condition that [Formula: see text] must satisfy is [Formula: see text] which we use to constrain the cosmological quantities mentioned above. In particular, we find that the tensor-to-scalar ratio [Formula: see text] (and as a consequence the energy scale of inflation) is bounded from below. We provide figures illustrating the behavior of these quantities as functions of [Formula: see text] for several values of [Formula: see text] and tables containing the bounds so obtained.