Abstract

In generic CFTs with a U(1) symmetry, the conformal data related to heavy operators of large U(1)-charge Q can be organised in a perturbative series in 1/Q. These perturbative expansions are generically factorially divergent. I will present the example of the 3D Wilson-Fisher O(2N) CFT in a suitable large-charge sector, where also N is taken to be large. Scaling dimensions in this model show double factorial growth in 1/Q generated by Worldline instantons saddles. These non-perturbative corrections can be systematically included in an unambiguous transseries which can be extrapolated to light low-charged sectors. The factorial growth can be related to the dilution and consequent breakdown of the heavy-density superfluid EFT phase which governs the large-Q sector of this CFT . The talk is based on work done in collaboration with Susanne Reffert, Domenico Orlando and Ioannis Kalogerakis from the University of Bern.