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GKM spaces and the nabla operator

Algebraic Geometry

Speaker: Erik Carlsson, UC Davis
Related Webpage: https://www.math.ucdavis.edu/~ecarlsson/
Location: 1147 MSB
Start time: Tue, Nov 16 2021, 11:00AM

I'll explain some recent results with A. Mellit which show that the matrix elements of the nabla operator, which is diagonal in the modified MacDonald basis of symmetric functions, compute the Frobenius character of the GKM cohomology of the "unramified affine Springer fiber." From this we can see the $q,t$-symmetry, and also a geometric interpretation of a conjecture about the signs of these coefficients.