Description
I will review recent progress in the understanding of tensionless null strings where the worldsheet becomes Carrollian and BMS3 appears as the residual gauge symmetry algebra replacing the two copies of the Virasoro algebra of the tensile string. After a recap of the classical aspects, I will focus on the quantum theory, which has many surprises in store including the appearance of three different theories from a single classical one, novel closed to open string transitions and Rindler physics on the worldsheet. In the final part of the talk, I will give some details of a model of microstates of the BTZ black hole based on a null string construction.
