High Energy Theory Seminar

Four-dimensional N=2 supersymmetric and superconformal quantum field theories take part in various 4d/2d correspondences, which map computations of certain protected data of the four-dimensional theory to problems in two-dimensional models. In this talk, I will explore the role of surface operators in two such correspondences, namely the AGT correspondence and the relation to chiral algebras. In the former, I will argue that a configuration of intersecting “M2-brane surface operators” in the four-dimensional theory translates in the insertion of a generic degenerate vertex operator, labeled by two arbitrary representations, in the Liouville/Toda correlator. In the correspondence with chiral algebras, considering the concrete example of free hypermultiplets, I will leverage a novel localization computation to identify the insertion of a class of surface operators orthogonal to the chiral algebra plane with the insertion of specific vertex operators in the chiral algebra.