Inflationary Potentials from the Exact Renormalisation Group

TL;DR

This paper demonstrates how slow-roll inflationary potentials can be derived from the exact renormalisation group equation for scalar fields, providing a non-perturbative approach that aligns with observational data.

Contribution

It introduces a novel method to obtain inflationary potentials from the IR limit of the exact renormalisation group without specifying a UV Lagrangian.

Findings

Effective potential supports slow-roll inflation.

Method applied explicitly to $$ theory.

Results consistent with recent cosmological observations.

Abstract

We show that an inflationary slow-roll potential can be derived as an IR limit of the non-perturbative exact renormalisation group equation for a scalar field within the mean-field approximation. The result follows without having to specify a Lagrangian for the UV theory at the Planck scale. We assume that the theory contains a scalar mode with suppressed coupling to other UV fields, and that higher derivative couplings are suppressed. The resulting effective potential gives rise to slow-roll inflation, which is fully consistent with the recent observations. As an example of how the proposed renormalisation group procedure works, we perform an explicit calculation in the $\phi^4$ theory.