主讲人：秦厚荣 教授（南京大学数学系）

时  间：2014年 12月12日（周五）下午16:30-17:30

地  点：必赢76net线路官网北二区教学楼 513

摘  要：In this talk, we study the Galois action on the extended Bloch groups of biquadratic and dihedral number fields. We show that if $F  $ is a biquadratic number field, then the index $Q_2(F)$ in Browkin and Gangl's formulas on the Brauer-Kuroda relation can only be $1$ or $2$. This is exactly what Browkin and Gangl predicted in their paper. Moreover we give the explicit criteria for $Q_2(F)=1$ or $2$ in terms of the Tate kernels. We also prove that $Q_2(F)=1$ or $p$ for any dihedral extension $F/\Q$ whose Galois group is the dihedral group of order $2p$, where $p$ is an odd prime.