We investigate the inflationary expansion of the universe induced by higher curvature corrections in M-theory. The inflationary evolution of the geometry is discussed in ref.[1], thus we succeed to analyse metric perturbations around the background. Especially we focus on scalar perturbations and analyse linearized equations of motion for the scalar perturbations. By solving these equations explicitly, we evaluate the power spectrum of the curvature perturbation. Scalar spectrum index is estimated under some assumption, and we show that it becomes close to 1.
Comment: 26 pages, 4 figures, references added, typos corrected, appendices B and C added, a reference and an explanation added in appendix B