Superconformal Subcritical Hybrid Inflation

Understand

We consider D-term hybrid inflation in the framework of superconformal supergravity.

• In part of the parameter space, inflation continues for subcritical inflaton field value.
• Consequently, a new type of inflation emerges, which gives predictions for the scalar spectral index and the tensor-to-scalar ratio that are consistent with the Planck 2015 results.
• The potential in the subcritical regime is found to have a similar structure to one in the simplest class of superconformal alpha attractors.