ON GALOIS PROJECTIVE GROUP RINGS

ABSTRACT. Let A be a ring with I, C the center of A and G ’ an inner automorphism group of A induced by [U in A / O in a finite group G whose order is invertible. Let AG ’ be the fixed subring of A under the action of G ’ If A is a Galcis extension of A G’ with Galois group G ’ and C is the center of the subring AG’u then A =AG ’ AG’U and the center of is also C. Moreover, if @AG’U is Azumaya over C, then A is a projective group ring. KEY WORDS AND PHRASES. Central Galois extensions, projective grou