For a Banach algebra A, we denote by .A* and .A** the first and the second duals of A respectively. Let T be a mapping from .A* to itself. In this article, we will investigate some stability results concerning the...For a Banach algebra A, we denote by .A* and .A** the first and the second duals of A respectively. Let T be a mapping from .A* to itself. In this article, we will investigate some stability results concerning the equations T(αf + βg) -= αT(f) + βT(g), T(af) = aT(f) andT(αf +βg) + T(αf - βg) =- 2α2T(f) + 2β2T(g) where f, g e .A*, a ∈ A, and α,β ∈ Q / {0}.展开更多
Let X, Y be Banach spaces and M be a linear subspace in X x Y = {{x,y}lx E X,y C Y}. We may view M as a multi-valued linear operator from X to Y by taking M(x) = {yl(x,y} C M}. In this paper, we give several criter...Let X, Y be Banach spaces and M be a linear subspace in X x Y = {{x,y}lx E X,y C Y}. We may view M as a multi-valued linear operator from X to Y by taking M(x) = {yl(x,y} C M}. In this paper, we give several criteria for a single-valued operator from Y to X to be the metric generalized inverse of the multi-valued linear operator M. The principal tool in this paper is also the generalized orthogonal decomposition theorem in Banach spaces.展开更多
文摘For a Banach algebra A, we denote by .A* and .A** the first and the second duals of A respectively. Let T be a mapping from .A* to itself. In this article, we will investigate some stability results concerning the equations T(αf + βg) -= αT(f) + βT(g), T(af) = aT(f) andT(αf +βg) + T(αf - βg) =- 2α2T(f) + 2β2T(g) where f, g e .A*, a ∈ A, and α,β ∈ Q / {0}.
基金Supported by National Natural Science Foundation of China (Grant No. 11071051)
文摘Let X, Y be Banach spaces and M be a linear subspace in X x Y = {{x,y}lx E X,y C Y}. We may view M as a multi-valued linear operator from X to Y by taking M(x) = {yl(x,y} C M}. In this paper, we give several criteria for a single-valued operator from Y to X to be the metric generalized inverse of the multi-valued linear operator M. The principal tool in this paper is also the generalized orthogonal decomposition theorem in Banach spaces.