Identities with bb-generalized derivations and generalized skew derivations on prime rings
Abstract
Let RR be a prime ring of characteristic different from 22, QrQr be the right Martindale quotient ring of RR, C=Z(Qr)C=Z(Qr) the extended centroid of RR, LL be a noncentral Lie ideal of RR, HH and GG be two nonzero bb-generalized derivations of RR. Suppose there exist fixed integers m,n≥1m,n≥1 such that H(um)un−unG(um)=0H(um)un−unG(um)=0, for all u∈Lu∈L, then either RR satisfies the standard identity s4(x1,…,x4)s4(x1,…,x4) or there is a′∈Qr such that H(x)=xa′, G(x)=a′x, for any x∈R, and one of the following holds:
(a) | there exists a′∈C, | ||||
(b) | [x1,x2]m and [x1,x2]n are C-linearly dependent. |
Then, in the second part of the paper we prove a similar result in the case H and G are generalized skew derivations of R such that H(xm)xn−xnG(xm)=0, for all x∈R.
Communicated by G. Scudo