String Theory seminar - Alejandra Castro Seminar

Abstract: I will discuss the large-N limit of two-dimensional symmetric product orbifolds. The goal is to single out which symmetric product orbifold theory could lead to a strongly coupled point in their moduli space, whose dual could be a semi-classical theory of AdS_3 gravity. To this end, we consider the symmetric product orbifold of N=(2,2) SCFT_2, and classify them according to two criteria.  The first criterion is the existence of a single-trace twisted exactly marginal operator in their moduli space.  The second criterion is a sparseness condition on the growth of light states in the elliptic genera. In this context, we encounter a strange variety: theories that obey the first criterion but the second criterion falls into a Hagedorn-like growth. I will explain why this may be counter-intuitive and discuss how it might be accounted for in conformal perturbation theory. I will also present a new infinite class of theories that obey both criteria, which are necessary conditions for their moduli spaces to contain a supergravity points.