Inflationary cosmology via quantum corrections in M-theory

We investigate inflationary cosmology by solving the effective action of M-theory, which consists of 11-dimensional supergravity and quartic terms of the Weyl tensor. The metric is simply expressed by two scale factors, one for the spatial directions and the other for the internal directions. Since the effective action of M-theory is constructed perturbatively, we also solve the equations of motion perturbatively. We will show that the classical solution of 11-dimensional supergravity does not represent inflationary expansion, but if we include the quantum corrections, the behavior of the solution around the very early time is modified and the inflationary scenario is realized. The inflation naturally ends when the scalar curvature becomes small and quartic terms of the Weyl tensor are negligible.