Theories of gravity with nonminimal matter-curvature coupling and the de Sitter swampland conjectures

TL;DR

This paper examines whether inflation driven by a scalar field in gravity theories with nonminimal matter-curvature coupling aligns with string theory's swampland conjectures, finding significant incompatibilities.

Contribution

It analyzes the compatibility of inflationary solutions in nonminimal matter-curvature coupled gravity theories with swampland conjectures, highlighting fundamental conflicts.

Findings

Slow-roll inflation is incompatible with swampland conjectures in these theories.

Most generic inflationary solutions cannot satisfy both slow-roll conditions and swampland criteria.

The results suggest limitations for embedding such inflation models in string theory.

Abstract

We discuss, in the context of alternative theories of gravity with nonminimal coupling between matter and curvature, if inflationary solutions driven by a single scalar field can be reconciled with the swampland conjectures about the emergence of de Sitter solutions in string theory. We find that the slow-roll conditions are incompatible with the swampland conjectures for a fairly generic inflationary solution in such alternative theories of gravity.