The Starobinsky Model from Superconformal D-Term Inflation

Understand

We point out that in the large field regime, the recently proposed superconformal D-term inflation model coincides with the Starobinsky model.

• In this 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.