设H是维数大于2的复Hilbert空间,β(H)代表H上所有有界线性算子全体.假定Φ是从β(H)到其自身的弱连续线性双射.我们证明了映射Φ满足对所有的A,B∈β(H),AB=BA^*蕴涵Φ(A)Φ(B)=Φ(B)Φ(A)^*当且仅当存在非零实数c和酉算子U∈(?)(H),使得Φ(A)=cUAU^*对所有的A∈β(H)成立.
Let H be a complex Hilbert space with dim Hβ3 andβ(H) the set of all bounded linear operators on H.Suppose thatΦ:β(H)→β(H) is a weakly continuous linear bijective map.We prove thatΦsatisfiesΦ(A)Φ(B)=Φ(B)Φ(A)^* whenever AB=BA^* for all A,B∈β(H) if and only ifΦhas the formΦ(A)= cUAU^-1 for all A∈(B)(H),where c is a nonzero real number and U∈β(H) is a unitary operator.