Singularities in inflationary cosmological models

TL;DR

This paper explores the types and conditions of singularities in inflationary cosmological models with scalar fields, revealing that most are weak and of type IV unless a negative potential is involved.

Contribution

It extends previous analyses by using generalized power expansions to identify all possible singularity scenarios in scalar field inflation models.

Findings

Most singularities are weak and of type IV.

Negative scalar potentials can lead to different singularity types.

The analysis broadens understanding of singularities in inflationary cosmology.

Abstract

Due to the accelerated expansion of the universe, the possibility of formation of singularities has changed from the classical Big Bang and Big Crunch singularities to include a number of new scenarios. In recent papers it has been shown that such singularities may appear in inflationary cosmological models with a fractional power scalar field potential. In this paper we enlarge the analysis of singularities in scalar field cosmological models by the use of generalised power expansions of their Hubble scalar and their scalar field in order to describe all possible models leading to a singularity, finding other possible cases. Unless a negative scalar field potential is considered, all singularities are weak and of type IV.