Abstract.Quasimap central charges are generating functions of GLSM invariants   associated to matrix factorizations. These functions admit different kinds of integral representations:   Mellin-Barnes type and Euler type. I plan to explain how the former arises and leads to relations of   central charges for different phases of GLSM. If the time permits, I will explain how to generalize these ideas for   K-theoretic invariants using elliptic central charges.