Remote Nordic HET seminar: Bogdan Stefanski

Speaker: Bogdan Stefanski

Title: Chern-Simons Origin of Superstring Integrability

Abstract: Costello proposed a unified framework for a variety of integrable models in terms of a four-dimensional topological/holomorphic Chern-Simons gauge theory. In this formulation, developed further by Costello, Yamazaki and Witten, many intricate properties of integrable models have a prosaic gauge-theory origin. For example, the Yang-Baxter equation follows from the topological nature of certain observables in 4d CS theory. Over the past decade integrability has been central in precision studies of holography, starting with the seminal work of Minahan and Zarembo. The integrable structures encountered in AdS/CFT are more elaborate than those found in conventional integrable models and it has been an outstanding challenge to find the origin of this new kind of integrability. In this talk, I will begin by reviewing the 4d CS approach to integrability. I will then show how the AdS5xS5 Green-Schwarz superstring can be obtained from a modification of 4d CS theory: the Beltrami-Chern-Simons theory. This reformulation of the superstring provides a novel way of understanding integrable holography in terms of a (relatively) simple gauge theory as well as the relations between different worldsheet formulations of superstrings.