The Resurgence of the Large Charge Expansion (Trieste)

Abstract

The large charge approach allows to describe special sectors of strongly-coupled systems. When another controlling parameter is present, it is still useful because it allows to unveil interesting mathematical structures and access previously unexplored parts of the spectrum. In this talk I will concentrate on the bosonic O(N) vector model and the fermionic NJL model in the large-N limit, give a geometrical interpretation of the asymptotic expansion of the dimension of the lowest operator of fixed charge, and use resurgence to resum this expansion. The results suggest a novel and still unexplored interplay between conformal symmetry and resurgence, offering an intuitive interpretation for the striking agreement of the large-charge predictions with lattice data, even in the case of the O(2) model.