学术报告

题      目： On the cohomology of spin hyperelliptic mapping class groups

报  告  人：王格非   博士  (邀请人：范飞飞 )

                                  东京大学

时      间：2022-9-29 15:00-16:00

地      点：西楼二楼会议室 

报告人简介:

       王格非，南开大学数学学院伯苓班本科，东京大学数理科学研究科硕士博士。主要从事代数拓扑和几何拓扑理论研究，曾在Homology Homotopy Appl.等SCI期刊发表论文。

摘      要：

       In this talk，I study the action of the Artin braid group B_{2g+2} on the set of spin structures on a hyperelliptic curve of genus g. As is known classically, the action reduces to that of the symmetric group S_{2g+2}. We compute the S_{2g+2}-orbits of the spin structures of genus g and the isotropy group G_i of each orbit. Moreover we compute the first, second and third rational cohomology group of the isotropy subgroup in the Artin braid group B_{2g+2} for each orbit.