COT1 - Dark Energy and Universe Acceleration |
Speaker_ |
Bieli, Roger |
Talk _ |
Accelerated expansion by non-minimally coupled scalar fields |
Abstract _ |
Cosmological models including a non-linear scalar field with an explicit coupling either to the space-time curvature or to the matter content are interesting generalizations of quintessence cosmologies. The asymptotics of spatially homogeneous models (Bianchi I to VIII) with the scalar field coupled to ordinary matter and evolving in a positive potential are presented and exponential or intermediate late-time inflation is found. On the other hand, it is shown that a non-minimal coupling to the space-time curvature offers a way to obtain deSitter expansion for exponential potentials of arbitrary steepness, i.e. for potentials where apparently no cosmological constant is present. |