Flat and projective modules.
We identify some situations where mappings related to left centralizers, derivations and generalized -derivations are free actions on semiprime rings. We show that for a left centralizer, or a derivation , of a semiprime ring the mapping defined by for all is a free action. We also show that for a generalized -derivation of a semiprime ring with associated -derivation a dependent element of is also a dependent element of Furthermore, we prove that for a centralizer and...
                                       
Let  be a prime ring with its Utumi ring of quotients  and extended centroid . Suppose that  is a generalized derivation of  and  is a noncentral Lie ideal of  such that  for all , where  is a fixed integer. Then one of the following holds:  
                  
                                       
Let  be a prime ring and  a nonzero ideal of  The purpose of this paper is to classify generalized derivations of  satisfying some algebraic identities with power values on  More precisely, we consider two generalized derivations  and  of  satisfying one of the following identities:  
                  
Generalized radical rings (braces) were introduced for the study of set-theoretical solutions of the quantum Yang-Baxter equation. We discuss their relationship to groups of I-type, virtual knot theory, and quantum groups.
Let be a prime ring with center and a nonzero right ideal of . Suppose that admits a generalized reverse derivation such that . In the present paper, we shall prove that if one of the following conditions holds: (i) , (ii) , (iii) , (iv) , (v) , (vi) for all , then is commutative.