共 22 条
Maps preserving the local spectrum of skew-product of operators
被引:17
作者:
Abdelali, Z.
[1
]
Achchi, A.
[1
]
Marzouki, R.
[1
]
机构:
[1] Univ Mohammed 5, Fac Sci, Dept Math, Rabat, Morocco
关键词:
Nonlinear preservers;
Local spectrum;
LINEAR-MAPS;
RADIUS;
D O I:
10.1016/j.laa.2015.07.019
中图分类号:
O29 [应用数学];
学科分类号:
070104 ;
摘要:
Let H and H be infinite dimensional complex Hilbert spaces and let B(H) be the algebra of all bounded linear operators on H. Let sigma(T)(h) denote the local spectrum of an operator T is an element of B(H) at any vector h is an element of H, and fix two nonzero vectors h(0) is an element of H and k(0) is an element of H. We show that if a map phi : B(H) -> B(K) has a range containing all operators of rank at most two and satisfies sigma(TS*) (h(0)) = sigma(phi)(T)phi(S)* (k(0)) for all T, S is an element of B(H), then there exist two unitary operators U and V in B(H,K) such that Uh(0) = alpha k(0) for some nonzero alpha is an element of C and phi (T) = UTV* for all T is an element of B(H). We also described maps phi : B(H) -> B(K) satisfying sigma(TS*T)(h(0)) = sigma phi(T) phi(S)*phi(T) (k(0)) for all T, S is an element of B(H), and with the range containing all operators of rank at most four. (C) 2015 Elsevier Inc. All rights reserved.
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页码:58 / 71
页数:14
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