Speaker：Qi Yan (Lanzhou University)

Time：2026-8-21 11:00

Location：Conference Room C610 at Administration Building at Haiyun Campus

Abstract:

In this talk, we introduce the partial-dual polynomial for hypermaps, extending the concept from ribbon graphs. We discuss the basic properties of this polynomial and characterize it for hypermaps with exactly one hypervertex containing a nonzero constant term. Additionally, we show that the partial-dual polynomial of a prime connected hypermap H is constant if and only if H is a plane hypermap with a single hyperedge.