Which linear-fractional composition operators are essentially normal?

被引:44
作者
Bourdon, PS [1 ]
Levi, D
Narayan, SK
Shapiro, JH
机构
[1] Washington & Lee Univ, Lexington, VA 24450 USA
[2] Cent Michigan Univ, Mt Pleasant, MI 48859 USA
[3] Michigan State Univ, E Lansing, MI 48824 USA
基金
美国国家科学基金会;
关键词
essentially normal; composition operator; linear-fractional map;
D O I
10.1016/S0022-247X(03)00005-2
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
We characterize the essentially normal composition operators induced on the Hardy space H-2 by linear-fractional maps; they are either compact, normal, or (the nontrivial case) induced by parabolic nonautomorphisms. These parabolic maps induce the first known examples of nontrivially essentially normal composition operators. In addition, we characterize those linear-fractionally induced composition operators on H-2 that are essentially self-adjoint, and present a number of results for composition operators induced by maps that are not linear-fractional. (C) 2003 Elsevier Science (USA). All rights reserved.
引用
收藏
页码:30 / 53
页数:24
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