1306.3471 (W. Buchmuller et al.)

The Starobinsky Model from Superconformal D-Term Inflation    [PDF]

W. Buchmuller, V. Domcke, K. Kamada

We point out that in the large field regime, the recently proposed superconformal D-term inflation model coincides with the Starobinsky model. In tis regime, the inflaton field dominates over the Planck mass in the gravitational kinetic term in the Jordan frame. Slow-roll inflation is realized in the large field regime for sufficiently large gauge couplings. The Starobinsky model generally emerges as an effective description of slow-roll inflation if a Jordan frame exists where, for large inflaton field values, the action is scale invariant, and the ratio $\hat{\lambda}$ of the inflaton self-coupling and the nonminimal coupling to gravity is tiny. The interpretation of this effective coupling is different in different models. In hybrid inflation it is determined by the scale of grand unification, $\hat{\lambda} \sim (\Lambda_{\rm GUT}/\Mp)^4$.

View original: http://arxiv.org/abs/1306.3471