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, β ( ϕ )ℛ̃, 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 β ( ϕ ) enable viable inflation — a scenario previously considered unattainable.