Speaker
Olivera Mišković
(Pontificia Universidad Católica de Valparaíso, Chile)
Description
Asymptotic symmetries at null boundaries often signal the presence of soft degrees of freedom and associated conserved charges. Here, these symmetries are studied in three-dimensional electromagnetism in two complementary contexts: null infinity of flat spacetime and the null boundary provided by the BTZ horizon. Both analyses lead to two sets of soft charges: the usual electric charge and an additional charge tied to a shift asymptotic symmetry. Together, these charges close into an infinite-dimensional Kac–Moody–type charge algebra with a nontrivial central extension.