Quantization of higher homotopy Chern-Simons theory in 4d and derived invariants of 2-ribbons

by Hank Chen

Thursday 1 Oct 2026, 11:00 → 12:00 Europe/Brussels

B/2nd floor-B.203 - Seminar room (Marc de Hemptinne (chemin du Cyclotron, 2, Louvain-la-Neuve))

2-Chern-Simons theory, or a generalized twisted 4d BF theory with gauged shift symmetry, is a natural generalization of Chern-Simons theory to 4-dimensional manifolds. It is part of the bestiary of higher AKSZ models. In this talk, I will present a framework, inspired by the work of Aleskeev-Grosse-Schomerus three decades ago, towards the quantization of 2-Chern-Simons higher holonomies in a sheaf-theoretic framework, based on the so-called "measureable categories" introduced by Crane and Yetter. Based on this framework I will then construct a quantum (derived) invariant of 2-ribbons from the quantum higher algebra (a Hopf category) underlying 2-Chern-Simons theory in the 4-disc. This serves as a higher-dimensional generalization of the Jones’s polynomials, and is an explicit realization of the 2-tangle hypothesis of Baez-Langford.