A viable Starobinsky-like inflationary scenario in the light of Planck and BICEP2 results

The recent CMB data from Planck and BICEP2 observations have opened a new window for inflationary cosmology. In this paper, we compare three Starobinsky-like inflationary scenarios: (i) The original Starobinsky proposal, (ii) a family of dynamically broken SUGRA models, and (iii) a class of "decaying" vacuum.(H) cosmologies. We then focus on the Lambda(H) variant, which spans the complete cosmic history of the universe from an early inflationary stage, followed by the "graceful exit" into the standard radiation regime, the matter epoch and, finally, the late-time accelerated expansion. Computing the effective potential we find that the "running" Lambda(H) models also provide a prediction for the tensor-to-scalar ratio of the CMB spectrum, r similar or equal to 0.16, which is compatible to within 1 sigma with the value r = 0.20(-0.05)(+0.07) recently measured by the BICEP2 collaboration.