New perspectives on constant-roll inflation

TL;DR

This paper explores constant-roll inflation using the $eta$-function formalism, deriving solutions and constructing generalized models that can end inflation and align with current cosmological observations.

Contribution

It introduces a $eta$-function approach to constant-roll inflation and develops generalized models with asymptotic solutions that naturally end inflation.

Findings

Solutions correspond to standard constant-roll models

Generalized models can end inflation naturally

Models are phenomenologically consistent with data

Abstract

We study constant-roll inflation using the $\beta$-function formalism. We show that the constant rate of the inflaton roll is translated into a first order differential equation for the $\beta$-function which can be solved easily. The solutions to this equation correspond to the usual constant-roll models. We then construct, by perturbing these exact solutions, more general classes of models that satisfy the constant-roll equation asymptotically. In the case of an asymptotic power law solution, these corrections naturally provide an end to the inflationary phase. Interestingly, while from a theoretical point of view (in particular in terms of the holographic interpretation) these models are intrinsically different from standard slow-roll inflation, they may have phenomenological predictions in good agreement with present cosmological data.