Let A be a unital algebra and M be a unital .A-bimodule. A linear map δ : A →M is said to be Jordan derivable at a nontrivial idempotent P ∈A if δ(A) o B + A o δ(B) =δ(A o B) for any A,B ∈ .4 with A o B...Let A be a unital algebra and M be a unital .A-bimodule. A linear map δ : A →M is said to be Jordan derivable at a nontrivial idempotent P ∈A if δ(A) o B + A o δ(B) =δ(A o B) for any A,B ∈ .4 with A o B = P, here A o B = AB + BA is the usual Jordan product. In this article, we show that if ,A = AlgAN is a Hilbert space nest Mgebra and M = B(H), or A =M= B(X), then, a linear mapδ: A→M is Jordan derivable at a nontrivial projection P ∈ N or an arbitrary but fixed nontrivial idempotent P∈ B(X) if and only if it is a derivation. New equivalent characterization of derivations on these operator algebras was obtained.展开更多
基金Supported by National Natural Foundation of China(11001194)Provincial International Cooperation Project of Shanxi(2014081027-2)
文摘Let A be a unital algebra and M be a unital .A-bimodule. A linear map δ : A →M is said to be Jordan derivable at a nontrivial idempotent P ∈A if δ(A) o B + A o δ(B) =δ(A o B) for any A,B ∈ .4 with A o B = P, here A o B = AB + BA is the usual Jordan product. In this article, we show that if ,A = AlgAN is a Hilbert space nest Mgebra and M = B(H), or A =M= B(X), then, a linear mapδ: A→M is Jordan derivable at a nontrivial projection P ∈ N or an arbitrary but fixed nontrivial idempotent P∈ B(X) if and only if it is a derivation. New equivalent characterization of derivations on these operator algebras was obtained.