Structural instability of Friedmann-Robertson-Walker cosmological models

TL;DR

This paper investigates the structural stability of Friedmann-Robertson-Walker cosmological models, revealing that singularities are generally unstable but stability can be achieved with a cosmological constant.

Contribution

It demonstrates how the inclusion of a Lambda-term extends the stability of cosmological models and analyzes the conditions for singularity stability.

Findings

Cosmological singularity is generally structurally unstable.

Adding a Lambda-term increases the set of stable models.

Stability depends on the energy conditions of the fluid.

Abstract

Cosmological singularity and asymptotic behaviour of scale factor of generalized cosmological models are analyzed in respect of their structural stability. It is shown, that cosmological singularity is structurally unstable for the majority of models with barotropic perfect fluid with strong energy condition. Inclusion of Lambda-term extends the set of structurally stable cosmological models.