In the standard scenario, gravitinos couple to ordinary matter only
through the gravitational interaction, so that their couplings are
Planck suppressed. This implies a (quite) long lifetime.
In general, particles with long lifetimes generate some issues in cosmology since if they decay after the BBN, then their decay products may destroy light elements,
destroying therefore the successful prediction of BBN.
These issues and the gravitino late abundance problem are reviewed in the framework of modified cosmologies.
|Parallel Session||Dark Matter, Astroparticle Physics|