Naked BPS singularities in AdS 3 supergravity

Anti-de Sitter (AdS) supergravity admits supersymmetric solutions that describe BPS defects. We investigate such solutions in AdS3 supergravity formulated as a Chern–Simons theory on and compute the Killing spinor equation on the BTZ geometry, looking for BPS solutions on the entire space of parameters. We focus our attention on defects that represent geometries with integer angular excesses corresponding to specific negative values of the BTZ mass, extending other results in the literature to all real values of mass and angular momentum. We argue that, in the semiclassical limit, the BPS defects can be associated with degenerate representations of the Virasoro symmetry at the boundary. The case of non-diagonal representations, describing stationary, non-static defects, is also discussed.