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Surveys in Mathematics and its Applications


ISSN 1842-6298 (electronic), 1843-7265 (print)
Volume 5 (2010), 297 -- 310

HIGHER *-DERIVATIONS BETWEEN UNITAL C*-ALGEBRAS

M. Eshaghi Gordji, R. Farokhzad Rostami and S. A. R. Hosseinioun

Abstract. Let A, B be two unital C*-algebras. We prove that every sequence of mappings from A into B, H = {h0, h1, ..., hm, ...}, which satisfy hm(3nuy) =Σi+j=mhi(3nu)hj(y) for each m ∈ N0, for all u∈ U(A), all y∈ A, and all n = 0, 1, 2, ..., is a higher derivation. Also, for a unital C*-algebra A of real rank zero, every sequence of continuous mappings from A into B, H = {h0, h1,..., hm, ...}, is a higher derivation when hm(3nuy) =Σi+j=mhi(3nu)hj(y) holds for all u∈ I1(Asa), all y∈ A, all n = 0, 1, 2, ... and for each m ∈ N0. Furthermore, by using the fixed points methods, we investigate the Hyers-Ulam-Rassias stability of higher *-derivations between unital C*-algebras.

2010 Mathematics Subject Classification: 39B52; 39B82; 46B99; 17A40.
Keywords: Alternative fixed point; Hyers--Ulam--Rassias stability; Higher *-derivation.

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M. Eshaghi Gordji R. Farokhzad Rostami
Department of Mathematics, Semnan University, Department of Mathematics,
P.O. Box 35195-363, Semnan, Iran. Shahid Beheshti University,
e-mail: madjid.eshaghi@gmail.com Tehran, Iran.

S. A. R. Hosseinioun
Department of Mathematics,
Shahid Beheshti University,
Tehran, Iran.




http://www.utgjiu.ro/math/sma