Quasi-pole inflation in metric-affine gravity

Abstract

We propose a new mechanism for inflationary model building in the framework of metric-affine gravity. Such a mechanism involves an inflaton non-minimally coupled with the Holst invariant. If the non-minimal coupling function has a zero point and it is very steep at that same point, the corresponding inflaton kinetic function will feature a quasi-pole behaviour, implying a canonically normalized potential featuring an exponential plateau, regardless of the shape of the original inflaton potential. The inflationary predictions in such a region are equivalent to the ones of Starobinsky inflation.

Comments: 17 pages, title changed, analysis expanded, extends the results of arXiv:2411.08031 to a larger class of models, version accepted for publication on GRG