FRW Cosmology with Non-positively Defined Higgs Potentials

TL;DR

This paper examines the classical dynamics of scalar fields with non-positive Higgs potentials in FRW cosmology, highlighting their implications for inflation, contraction, and reheating in models inspired by string theory.

Contribution

It introduces a class of local Higgs models with non-positive potentials derived from non-local string-inspired models, analyzing their cosmological evolution.

Findings

Reheating is absent due to contraction phases.

Inflation occurs near the hill top with limited slow-roll regions.

Models can produce sufficient e-foldings despite contraction phases.

Abstract

We discuss the classical aspects of dynamics of scalar models with non-positive Higgs potentials in the FRW cosmology. These models appear as effective local models in non-local models related with string field theories. After a suitable field redefinition these models have the form of local Higgs models with a negative extra cosmological term and the total Higgs potential is non-positively defined and has rather small coupling constant. The non-positivity of the potential leads to the fact that on some stage of evolution the expansion mode gives place to the mode of contraction, due to that the stage of reheating is absent. In these models the hard regime of inflation gives place to inflation near the hill top and the area of the slow roll inflation is very small. Meanwhile one can obtain enough e-foldings before the contraction to make the model under consideration admissible to describe inflation.