Let N and M be nests on Banach spaces X and Y over the real or complex field F, respectively, with the property that if M ∈ M such that M_ =M, then M is complemented in Y. Let AlgN and AlgM be the associated nest alg...Let N and M be nests on Banach spaces X and Y over the real or complex field F, respectively, with the property that if M ∈ M such that M_ =M, then M is complemented in Y. Let AlgN and AlgM be the associated nest algebras. Assume that Ф : AlgN → AlgM is a bijective map. It is proved that, if dim X = ∞ and if there is a nontrivial element in N which is complemented in X, then Ф is Lie multiplicative (i.e. Ф([A, B]) = [Ф(A), Ф(B)] for all A, B ∈ AlgN) if and only if Ф has the form Ф(A) = TAT^-1 + τ(A) for all A ∈ AlgAN or Ф(A) = -TA^*T^-1 + τ(A) for all A ∈ AlgN, where T is an invertible linear or conjugate linear operator and τ : AlgN →FI is a map with τ([A, B]) = 0 for all A, B ∈ AlgN. The Lie multiplicative maps are also characterized for the case dim X 〈 ∞.展开更多
Let H and K be indefinite inner product spaces. This paper shows that a bijective map φ:B(H) →B(K) satisfies φ(AB^+ + B^+A) = φ(A)φ(B)^+ + φ(B)^+φ(A) for every pair A, B ∈ B(H) if and on...Let H and K be indefinite inner product spaces. This paper shows that a bijective map φ:B(H) →B(K) satisfies φ(AB^+ + B^+A) = φ(A)φ(B)^+ + φ(B)^+φ(A) for every pair A, B ∈ B(H) if and only if either φ(A) = cUAU^+ for all A or φ(A) = cUA^+U^+ for all A; φ satisfies φ(AB^+A) = φ;(A)φ;(B)^+φ;(A) for every pair A, B ∈ B(H) if and only if either φ(A) = UAV for all A or φ(A) = UA^+V for all A, where At denotes the indefinite conjugate of A, U and V are bounded invertible linear or conjugate linear operators with U^tU = c^-1I and V^+V = cI for some nonzero real number c.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 10871111)Tian Yuan Foundation of China (Grant No. 11026161)Foundation of Shanxi University
文摘Let N and M be nests on Banach spaces X and Y over the real or complex field F, respectively, with the property that if M ∈ M such that M_ =M, then M is complemented in Y. Let AlgN and AlgM be the associated nest algebras. Assume that Ф : AlgN → AlgM is a bijective map. It is proved that, if dim X = ∞ and if there is a nontrivial element in N which is complemented in X, then Ф is Lie multiplicative (i.e. Ф([A, B]) = [Ф(A), Ф(B)] for all A, B ∈ AlgN) if and only if Ф has the form Ф(A) = TAT^-1 + τ(A) for all A ∈ AlgAN or Ф(A) = -TA^*T^-1 + τ(A) for all A ∈ AlgN, where T is an invertible linear or conjugate linear operator and τ : AlgN →FI is a map with τ([A, B]) = 0 for all A, B ∈ AlgN. The Lie multiplicative maps are also characterized for the case dim X 〈 ∞.
基金Project supported by the National Natural Science Foundation of China (No.10471082) the Shanxi Provincial Natural Science Foundation of China (No.20021005).
文摘Let H and K be indefinite inner product spaces. This paper shows that a bijective map φ:B(H) →B(K) satisfies φ(AB^+ + B^+A) = φ(A)φ(B)^+ + φ(B)^+φ(A) for every pair A, B ∈ B(H) if and only if either φ(A) = cUAU^+ for all A or φ(A) = cUA^+U^+ for all A; φ satisfies φ(AB^+A) = φ;(A)φ;(B)^+φ;(A) for every pair A, B ∈ B(H) if and only if either φ(A) = UAV for all A or φ(A) = UA^+V for all A, where At denotes the indefinite conjugate of A, U and V are bounded invertible linear or conjugate linear operators with U^tU = c^-1I and V^+V = cI for some nonzero real number c.