An exponential correction to Starobinsky's inflationary model

Abstract

We analyse $f(R)$ theories of gravity from a dynamical system perspective, showing how the $R^2$ correction in Starobinsky's model plays a crucial role from the viewpoint of the inflationary paradigm. Then, we propose a modification of Starobinsky's model by adding an exponential term in the $f(R)$ Lagrangian. We show how this modification could allow to test the robustness of the model by means of the predictions on the scalar spectral index $n_s$.

Latex file, 6 pages, 2 figures. For the Proceedings of the International Conference on Particle Physics and Astrophysics, ICPPA 2016, October 10-14 2016, Moscow, Russia