I’m currently working in collaboration with John Ellis, Keith Olive, Dimitri Nanopoulos and Natsumi Nagata on an embedding of Starobinsky inflation in a no-scale supersymmetric flipped-SU(5) model. The challenge is to relate the inflationary epoch with lower scale phenomenology; as demonstrated in our previous work with SO(10), Cosmic Microwave Background observables such as the scalar tilt and the tensor-to-scalar ratio can be directly linked to the masses of the Standard Model neutrinos. Depicted in the figure is a snapshot of the calculation of the inflaton decay rate to scalars; as in supersymmetric models a copious amount of gravitinos can be produced during reheating, the observed Dark Matter abundance will place constraints on the Yukawa couplings of the model.

A few references:

I. Antoniadis, J. R. Ellis, J. S. Hagelin and D. V. Nanopoulos, *Supersymmetric Flipped SU(5) Revitalized*, Phys. Lett. B **194**, 231 (1987).

J. R. Ellis, D. V. Nanopoulos and K. A. Olive, *Flipped heavy neutrinos: From the solar neutrino problem to baryogenesis*, Phys. Lett. B **300**, 121 (1993).