Morphism Groupoids and Groupoid Extensions
报告人：Chengyong Du (Sichuan Normal University)
时间：2018-12-27 15:15 - 2018-12-27 16:15
地点：Room 9, Quan Zhai, BICMR
In this talk we will introduce various constructions on (Lie) groupoids originated from orbifold Gromov-Witten theory. We first consider the construction of groupoid of morphisms of groupoids (Morphism groupoids), this would be the foundation for studying moduli spaces in orbifold Gromov-Witten theory. Then we consider groupoid extension/fibration with fiber being groupoids. A gerbe is a special case of groupoid extension. We classify groupoid extensions. Finally, we discuss the morphism groupoids of fiber class morphism to a groupoid extension. This is the first step to study the orbifold Gromov-Witten theory of groupoid extensions. This talk is based on recent joint works with B. Chen, R. Wang and Y. Wan.