Popis: |
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 K. Hiraga and Y. Hyakutake, Prog. Theor. Exp. Phys. 2018, 113B03 (2018), which we follow to analyze metric perturbations around the background. We especially focus on scalar perturbations and analyze linearized equations of motion for the scalar perturbations. By solving these equations explicitly, we evaluate the power spectrum of the curvature perturbation. The scalar spectrum index is estimated under some assumptions, and we show that it becomes close to 1. |