Thick-Brane Cosmology

We search for time-dependent solutions for the 5-dimensional system of a scalar field canonically coupled to gravity. Time-independent and time-dependent scalar field configurations with the most general homogeneous and isotropic 4D metric are considered. For the case of time-independent scalar field, the time evolution of the scale factor is obtained for different values of the spatial curvature $k=0,\pm 1$. In the case of time-dependent scalar field, two classes of solutions are discussed and an extension of the superpotential formalism is proposed.