10/29/2009
Jonathan Bloom
Columbia University
Link surgery, monopole Floer homology, and odd Khovanov homology
I'll describe new bigraded invariants of a framed link in a 3-manifold, which arise as the pages of a spectral sequence generalizing the surgery exact triangle in monopole Floer homology. The construction relates the topology of link surgeries to the combinatorics of polytopes called graph associahedra. For a link in the 3-sphere, we obtain a sequence of bigraded vector spaces, interpolating between the reduced, Z/2Z Khovanov homology and a version of the monopole Floer homology of the branched double cover. This perspective also yields a simple, topological proof that odd Khovanov homology is mutation invariant. Paper reference: arxiv.org/abs/0903.3746, arxiv.org/abs/0909.0816