Galois Theory with Infinitely Many Idempotents
Galois Theory with Infinitely Many Idempotents
In 1942 Artin proved the linear independence, over a field S, of distinct automorphism of S; in other words if G is a finite group of automorphisms of S and R is the fixed field, then Horn^S, S) is a free S-module with G as basis. Since then, this last …