Let G be a group and denote by $k[G]$ the group ring over a commutative ring $k$. Is then $k[G^n]\cong k[G]^{\otimes n}$? If so, what is the isomorphism?
Thanks a lot!
Let G be a group and denote by $k[G]$ the group ring over a commutative ring $k$. Is then $k[G^n]\cong k[G]^{\otimes n}$? If so, what is the isomorphism?
Thanks a lot!
Yes. This follows from the fact that
$$k[G \times H] \ni \sum c_{ij} (g_i \times h_j) \mapsto \sum c_{ij} g_i \otimes h_j \in k[G] \otimes_k k[H]$$
is an isomorphism.