GRB follow-up and science with THESEUS/IRT

The aim of the space mission concept THESEUS is to continue to collect and study the GRB events like Swift. It will allow us to study the early Universe. Moreover, it will offer us to study with unprecedented sensitivity GRB emission and to measure the redshift for the bursts with z>5. In this work, we investigate the advantages of a optical and near-infrared telescope mounted on the same satellite that is triggered by the GRB like THESEUS/IRT. Afterwards, we investigate the possible future developments in the GRB science, first for the prompt phase and the for afterglow phase. We find that more than half of the sources detected by THESEUS, and will never be visible from a a ground-based telescope. Moreover, only ∼50% of all observable sources are visible within one hour, i.e.