Centrally-extended homoderivations on rings

Abstract

Let R be a ring with center Z(R). A mapping H from R into itself is called a centrally-extended homoderivation on R if for each x, y ∈ R, H(x+y) - H(x) - H(y) ∈ Z(R) and H(xy) - H(x)H(y)- H(x)y - xH(y) ∈ Z(R). We present examples of mappings that are centrally-extended homoderivations but not homoderivations. We also study the effect of such mappings on Z(R) and prove some commutativity results.