Gravitino Dark Matter with Stop as the NLSP

Gravitino is one feasible candidate for the dark matter in supergravity models. With its couplings being suppressed by the Plank mass, gravitino interacts very weakly with other particles, making its direct detection, or production at colliders practically impossible. The signatures of this scenario mainly arise from the next lightest supersymmetric particle (NLSP) which is metastable due to the very weak coupling. There are many possibilities for the NLSP, and here I will review the feasibility of stop particle as the NLSP and discuss its phenomenology.