Theory HEP Seminar

Symmetries and twining genera in symmetric orbifolds of K3

Roberto Volpato

University of Padova

I will discuss the possible groups of discrete symmetries of 2-dimensional conformal field theories given by non-linear sigma models on (deformations of) symmetric orbifolds Symⁿ K3 of K3 surfaces. As is well-knwon, these models describe the dynamics of D1-D5 systems in type IIB string theory compactified on a K3 surface, and in the large N limit they are dual to AdS₃ × S³ × K3. I will first give a classification of their group of symmetries. Then, I will describe the twining genera, refinements of the ellitpic genus that describe the action of these symmetries on the space of states of the models.