The Dynamics of Scalar Fields in Cosmology

Abstract

Scalar field models have been a focal point in cosmology during the last two decades or so. They play a central role in inflationary models, they arise in modified gravity theories that extend Einstein’s General Relativity (GR) which are, often, quantum motivated, and, recently, they have been put forward as a dark component of the universe. Here we analyse their dynamics in the framework of isotropic cosmologies presenting an unified approach that encompasses models both in Einstein’s GR and more general metric gravity theories. We perform a qualitative analysis of the major dynamical features of these models, discussing the existence of asymptotic regimes and their connection to a classification of the scalar fields potentials and couplings. A special interest is devoted to the interplay between scalar fields and matter which gives rise to scaling behaviour.