2
votes
0answers
37 views

Why do the two topologies on a Galois group coincide?

In the following one is referred to the book. At this page, the author defines Krell topology on a Galois group(not necessarily finite); at the 22-th page of the same book, the quthor defines then the ...
2
votes
0answers
102 views

Question on $\operatorname{res}^G_U \circ \operatorname{cor}^U_G = N_{G/U}$

This is probably a very basic question, but I can't wrap my head around it. Given a normal open subgroup $U$ of a profinite group $G$ and a $G$-Module $A$ we have the following equation in group ...