School of Physics and Astronomy

Density inhomogeneities in scalar field cosmologies: a dynamical system approach

27 November 2013

Time: 4:30pm
Venue: Maths 103

The London Relativity and Cosmology Seminar
Artur Alho (Lisbon)

We derive a set of equations monitoring the evolution of covariant and gauge-invariant linear scalar perturbations of Friedman-Lema\^itre-Robertson-Walker models with multiple interacting nonlinear scalar fields. We use a dynamical systems' approach in order to perform a stability analysis for some classes of scalar field potentials. In particular, using a recent approximation for the background solution, we derive conditions under which homogenization occurs for chaotic (quadratic and quartic potentials) and new inflation. We also prove a cosmic no-hair result for power-law inflation and its generalisation for two scalar fields with independent exponential potentials (assisted power-law inflation).