Current trimester: TQFT and Knot Theory
The kickoff event took place at IHP on 22.04.2026 (https://indico.math.cnrs.fr/event/16226/)
Mathematics
Graphical calculus for twisted pivotal categories
byBenjamin Haïoun
Abstract:Graphical calculus provides a convenient way to represent objects and morphisms in a monoidal category using strands in the plane. This viewpoint extends naturally to more general surfaces and leads to constructions of TQFTs, such as the Turaev–Viro theories. In order to obtain oriented TQFTs, one usually uses a pivotal structure. In this talk, I will describe a more general approach based on a twisted pivotal structure, as predicted by the cobordism hypothesis. I will introduce a graphical calculus for these structures, which involves foliated surfaces and many drawings.