COT1 - Dark Energy and Universe Acceleration |
Speaker_ |
Qiang, Li-e |
Co-autors |
Yongge Ma |
Talk _ |
Five-dimensional Brans-Dicke Theory and Cosmic Acceleration |
Abstract _ |
We consider a 5-dimensional scalar-tensor theory which is a direct generalization of the original 4-dimensional Brans-Dicke theory to 5-dimensions. By assuming that there is a hypersurface-orthogonal spacelike Killing vector ¯eld in the underlying 5-dimensional space-time, the theory is reduced to a 4-dimensional theory where the 4-metric is coupled with two scalar ¯elds. The cosmological implication of this reduced theory is then studied in the Robertson-Walker model. It turns out that the two scalar ¯elds may account naturally for the present accelerated expansion of our universe. The observational restriction of the reduced cosmological model is also analyzed. |