Symmetry-breaking inflation in non-minimal metric-affine gravity

Abstract

We study symmetry-breaking inflation within the framework of metric-affine gravity. By introducing a non-minimal coupling, $\beta (\varphi )\tilde{\mathcal{R}}$, between the Holst invariant and the inflaton, both small-field and large-field inflationary predictions can be brought into agreement with the latest observational constraints. Remarkably, even for sub-Planckian vacuum expectation values, appropriately chosen values of $\beta (\varphi )$ enable viable inflation, a scenario previously considered unattainable.

19 pages, 10 figures, matches published version