Non-thermal leptogenesis and gravitino problem in inflaton decay

TL;DR

This paper investigates the challenges of achieving successful non-thermal leptogenesis and avoiding gravitino overproduction in inflaton decay scenarios, finding that these goals are mutually incompatible under current constraints.

Contribution

It provides a detailed analysis of gravitino production mechanisms and their impact on baryon asymmetry and Big Bang nucleosynthesis constraints in inflaton decay models.

Findings

Simultaneous achievement of baryon asymmetry and BBN constraints is impossible.

Thermal and inflaton decay gravitino production mechanisms are both significant.

Parameter space for successful leptogenesis is severely limited.

Abstract

In the present work we discuss baryon asymmetry in the non-thermal leptogenesis scenario and gravitino cosmology for an unstable gravitino with inflaton decay. We take into account two production mechanisms for gravitino, namely thermal production and inflaton decay. We wish to show in plots the allowed parameter space so that the BBN constraint and the requirement for the right baryon asymmetry are satisfied at the same time. However our analysis shows that it is impossible to achieve both goals simultaneously.