Particle production from non-minimal coupling in a symmetry breaking potential transporting vacuum energy

TL;DR

This paper introduces a novel inflationary model where a non-minimally coupled inflaton with a symmetry breaking potential transforms vacuum energy into geometric particles, potentially explaining dark matter and inflation dynamics.

Contribution

It proposes a new inflation scenario involving non-minimal coupling and vacuum energy transformation into geometric particles, with implications for dark matter and cosmological constant behavior.

Findings

Vacuum energy can convert into geometric particles during inflation.

Dark matter may originate from geometric quasi-particles.

Large field inflaton is favored over small field due to gravitational considerations.

Abstract

We propose an inflationary scenario where the inflaton field is non-minimally coupled to spacetime curvature and inflation is driven by a vacuum energy symmetry breaking potential without specifying \emph{a priori} whether the inflaton field is small or large. As we incorporate vacuum energy into our analysis, we further explore the implications of a non-zero potential offset in relation to the emergence of inflationary dynamics. Thus, we propose that vacuum energy can transform into particles as a result of the transition triggered by spontaneous symmetry breaking. This entails a vacuum energy cancellation that yields an effective cosmological constant during inflation by virtue of a quasi-de Sitter evolution and shows that the vacuum energy contribution can manifest as \emph{geometric particles} produced by inflaton fluctuations, with particular emphasis on super-Hubble modes. We conjecture these particles as \emph{quasi-particles} arising from interaction between the inflaton and spacetime geometry, enhanced by non-minimal coupling. Specifically, we propose that dark matter arises from a pure geometric quasi-particle contribution, and we quantify the corresponding dark matter candidate ranges of mass. In this scenario, we further find that a zero potential offset leads to a bare cosmological constant at the end of inflation, while a negative offset would require an additional kinetic (or potential) contribution in order to be fully-canceled. In this regard, we conclude that the scenario of large field inflaton is preferred since it necessitates a more appropriate selection of the offset. Our conclusion is reinforced as small field inflaton would lead to a significant screening of the Newtonian gravitational constant as inflation ends.