Relatore: Dott.ssa Agnese BissiLuogo: Sala FeynmanE-mail organizzatore: bonini@fis.unipr.itAbstract:In this talk I will present how to construct modular invariant interpolating functions fully compatible with S-duality. I will also discuss the problem of resumming perturbative expansions for anomalous dimensions of low twist, low spin, non protected operators in N=4 SYM. When the rank of the gauge group is small, the interpolations suggest that anomalous dimensions of leading twist operators take their maximum value at a specific point in the fundamental region. If time permits, I will show how to study the phenomenon of level crossing by using such interpolating functions.
