On nilpotent elements of ore extensions
Abstract
Let RR be an associative ring with unity, αα be an endomorphism of RR and δδ an αα-derivation of RR. We introduce the notion of αα-nilpotent p.p.-rings, and prove that the αα-nilpotent p.p.-condition extends to various ring extensions. Among other results, we show that, when RR is a nil-αα-compatible and 22-primal ring with Nil(R)Nil(R) nilpotent, then Nil(R[x;α,δ])=Nil(R)[x;α,δ]Nil(R[x;α,δ])=Nil(R)[x;α,δ]; and when RR is a nil Armendriz ring of skew power series type with Nil(R)Nil(R) nilpotent, then Nil(R[[x;α]])=Nil(R)[[x;α]],Nil(R[[x;α]])=Nil(R)[[x;α]], where Nil(R)Nil(R) is the set of nilpotent elements of RR. These results extend existing results to a more general setting.
Communicated by L. Bokut