A link L living in a thickened annulus (R^2∖ {0})×[0, 1] is called an annular link. The ambient space equips the bigraded Khovanov chain complex of L with an additional annular (filtration) grading, and the associated graded complex computes the annular Khovanov homology, AKh(L). Understanding annular knots and links is important in many different contexts in low-dimensional topology; this lecture series will survey some existing and potential relationships between AKh and contact topology, knot concordance, representation theory, and more.
Lecture 3: Structure of Annular Khovanov Homology: sl_2(C) action; Annular Khovanov-Lee Homology.
This lecture was part of the workshop "Perspectives on quantum link homology theories", see https://cbz20.raspberryip.com/Perspectives-2021