Effects of the imaginary inflaton component in supergravity new inflation

Understand

When models of new inflation are implemented in supergravity, the inflaton is a complex and not a real scalar field.

• As a complex scalar field has two independent components, supergravity models of new inflation are naturally two-field models.
• In this paper, we use the delta N formalism to analyse how the two-field behaviour modifies the usual single-field predictions.
• We find that the model reduces to the single-field limit if the inflaton mass term is sufficiently small.