3d GLSMs, Quantum K-Theory, and Schubert Varieties

Speaker: 张昊

Abstract: In this talk, I will discuss how 3d A-twisted GLSMs provide a physical realization of quantum K-theory. Working on the Coulomb branch, I will show how the effective twisted superpotential encodes quantum K-theory ring relations for projective spaces, Grassmannians, and flag manifolds. In physics, Wilson loops are often used as a basis for the quantum K-theory ring; here, we introduce new line defects that correspond instead to the Schubert basis in mathematics. These defects are described by coupled 1d-3d gauge theories, which geometrically realize Schubert varieties and their resolutions. Moreover, the flavored Witten index of the 1d theory reproduces Grothendieck polynomials (and their analogues) associated with the Schubert classes.

Time: 14:00~16:00, 2026-02-03

Location: R1410, SIMIS

Zoom Meeting ID: 891 8285 5510 Passcode: SIMIS