IASM Preprint Series 2020-02:Level correspondence of K-theoretic I-function in Grassmann Duality


Level correspondence of K-theoretic I-function in Grassmann Duality

Hai Dong and Yaoxiong Wen


In this paper, we prove a class of nontrivial q-Pochhammer symbol identities with extra

parameters by iterated residue method. Then we use these identities to find relations of the

quasi-map K-theoretical I-functions with level structure between Grassmannian and its dual

Grassmannian. Here we find an interval of levels within which two I-functions are the same,

and on the boundary of that interval, two I-functions are intertwining with each other. We call

this phenomenon level correspondence in Grassmann duality.