A note on Wilson-'t Hooft operators

Understand

We find the basic ingredients required to compute the Operator Product Expansion of Wilson-'t Hooft operators in N=4 super-Yang-Mills theory with gauge group G=PSU(3).

• These include the geometry of certain moduli spaces of BPS configurations in the presence of 't Hooft operators and vector bundles over them.
• The bundles arise in computing the OPE due to electric degrees of freedom in dyonic operators.
• We verify our results by reproducing the OPE of 't Hooft operators predicted by S-duality.