Theorem detail

Alias: Maschke's Theorem

Statement: For any ring $R$ and group $G$, the group ring $R[G]$ is semisimple iff $R$ is semisimple and $|G|$ is a unit in $K$.

Link:

Reference(s)

  • Lam, Tsit-Yuen., A First Course In Noncommutative Rings, Vol. 131. Springer, (2001). Theorem 6.1 Page 83