Influence of scalar fields on the approach to a cosmological singularity

The method of consistent potentials (MCP) is used to explain how a minimally coupled (classical) scalar field can suppress mixmaster oscillations in the approach to the singularity of generic cosmological spacetimes. The MCP predicts the nature of the approach to the singularity by substitution of the velocity term dominated (VTD) solution, obtained by neglecting terms in Einstein’s equations containing spatial derivatives, into the neglected terms. If these remain small, the approach to the singularity is predicted to be asymptotically VTD (AVTD). Addition of the scalar field to vacuum Bianchi type IX (mixmaster), vacuum U(1) symmetric, and magnetic Gowdy cosmologies changes the MCP prediction from that for an oscillatory approach to the singularity to one that is AVTD. Numerical simulations are shown to support these predictions.