令H为维数大于2的复Hilbert空间,Bs(H)为H上所有有界自伴算子构成的实线性空间.该文给出Bs(H)上满足[Φ(A~2),Φ(A)]=0对所有A∈Bs(H)成立的可加双射Φ的刻画,在Φ(Fs(H))■RI或RI■Φ(RI)的条件下证明了上述Φ具有形式Φ(A)=cUAU*+f(A)I,A∈Bs(H),其中c∈R,c≠0,U:H→H是酉算子或共轭酉算子,而f是Bs(H)上的可加泛函.
Let H be a complex Hilbert space with dimension greater than 2 and B_s(H) thespace of all self-adjoint operators in B(H).A characterization is given for additive bijective mapΦon B_s(H) satisfying[Φ(A~2),Φ(A)]=0 for all A∈B_s(H).It is showed that,ifΦ(F_s(H))■RIor RI■Φ(RI),thenΦhas the formΦ(A)=cU AU~*+f(A)I,A∈B_s(H),where c∈R,c≠0,U:H→H is is an unitary or conjugate unitary operator,and f is an additive real functional ofB_s(H).