Contraction algebras, plumbings and flops

Michael Wemyss (University of Glasgow)

Monday 26th October, 2020 16:00-17:00 Online


I will construct geometric models, on both the A-side and B-side of mirror symmetry, that are controlled by potentials on the two-cycle quiver.  The cohomology of objects in the underlying categories are naturally modules for the associated contraction algebra, and I will explain how to use this information to obtain otherwise tricky results, such as a classification of spherical (and more generally, fat-spherical) objects.  This has purely topological corollaries.  One feature, which I will probably gloss over but is actually fundamental, is that our categories have a dependence on the characteristic of the ground field.  This is joint work with Ivan Smith.

The talk will be preceded by a 30 minute tea time. The Zoom link for the seminar is and the passcode is the genus of the two-dimensional sphere (4 letters, all lowercase).

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