GKM spaces and the nabla operator

Abstract: 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.

algebraic geometry

Audience: researchers in the topic

UC Davis algebraic geometry seminar