Localizations of Hereditary Noetherian Rings
A theorem of Utumi states that if R is a right self-injective ring such that every maximal ideal has nonzero annihilator, then R modulo the Jacobson radical J is a finite product of simple rings and is a von Neuman regular ring. We prove two theorems and a conjecture of Shamsuddin that characterize when R itself is a von Neumann ring, using a splitting theorem of the author on when the maximal regular ideal of a ring splits off.
If is a prime ring such that is not completely reducible and the additive group is not complete, then is slender.
Let be a prime ring, with no non-zero nil right ideal, a non-zero drivation of , a non-zero two-sided ideal of . If, for any , , there exists such that , then is commutative. As a consequence we extend the result to Lie ideals.
Let be a semiprime ring and an additive mapping such that holds for all . Then is a left centralizer of . It is also proved that Jordan centralizers and centralizers of coincide.