Constraints on modular inflation in supergravity and string theory

Understand

We perform a general algebraic analysis on the possibility of realising slow-roll inflation in the moduli sector of string models.

• This problem turns out to be very closely related to the characterisation of models admitting metastable vacua with non-negative cosmological constant.
• In fact, we show that the condition for the existence of viable inflationary trajectories is a deformation of the condition for the existence of metastable de Sitter vacua.
• This condition depends on the ratio between the scale of inflation and the gravitino mass and becomes stronger as this parameter grows.