Thursday November 8th, 2018
Time: 4:00 PM - 5:00 PM
Title: Lefschetz thimbles from Fermi curves
Speaker: Nikita Nekrasov, SCGP
Location: Math Tower P-131
The steepest descent method of evaluating oscillatory integrals has been recently connected to the localization computations in topological field theories. The infinite-dimensional analogues of such computations lead to exact quantization conditions in quantum mechanics. In the talk I will review the recent progress in the next step of this program. We study the functional Lefschetz thimbles, i.e. the possible path integral contours, in the examples of the O(N) model of two dimensional quantum field theory. Specifically, we find a large class of complex critical points of the sigma model actions which are relevant for the theory in finite volume at finite temperature, using the theory of finite-gap potentials. Based on the joint work with I. Krichever.