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Topology/Geometry Seminar

Surgery Exact Triangles in Instanton Theory

Deeparaj Bhat (MIT)

Location:  Hill 705
Date & time: Tuesday, 07 November 2023 at 4:00PM - 5:00PM

Abstract:
We prove an exact triangle relating the knot instanton homology to the instanton homology of surgeries along the knot. As the knot instanton homology is computable in many instances, this sheds some light on the instanton homology of closed 3-manifolds. We illustrate this with computations in the case of some surgeries on the trefoil. In particular, we show the Poincaré homology sphere is not an instanton L-space (with Z/2 coefficients), in contrast with Heegaard Floer and monopole Floer theories. Finally, we sketch the proof of the triangle.