2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/100947We explain how rank two Frobenius extensions of commutative rings lead to link homology theories and discuss relations between these theories, Bar-Natan theories, equivariant cohomology and the Rasmussen invariant.13 pages, 2 figuresQuantum AlgebraGeometric Topology57M27text