PHYSICS SEMINAR
The Qualitative Dynamics of General Scalar Field Cosmology
Charles Protheroe
Monday, April 30, 2012
11:00 am
Johnson 103
There is much uncertainty as to what kind of scalar field is appropriate to use in models of the early universe, inflation, and late-time quintessence. We attempt to obtain a greater understanding of the general evolution of scalar field universes by examining the dynamics of an unspecified scalar field fueling the expansion of a Friedmann-Lemaitre-Robertson-Walker universe in the context of General Relativity. The goal of this study is to further the understanding of the dynamics of our universe, without relying on speculative advances in the theory of particle physics. We study the dynamics through qualitative phase-space methods with a focus on the spatially flat case. This includes: examining the geometry of the phase space, locating the equilibrium points of the system (which turn out to be de Sitter spaces with a constant scalar field), studying their stability through both a third-order perturbation analysis and Lyapunov functions, and performing late-time asymptotic analysis. As we do not specify the scalar field's origin, or potential energy density, our results are very general and independent of the high-energy model.
