Abstract
In this paper, we study class A composition operators Cφ on the Hardy space H2. We show that if Cφ belongs to class A, then 0 is a fixed point of the symbol φ. As a corollary, we obtain that every invertible class A composition operator is unitary. Moreover, we examine spectral properties and the commutants of class A composition operators. We also prove that if φ is a linear fractional self-map of D into itself, then Cφ belongs to class A if and only if it is subnormal. Finally, we provide some conditions under which Cφ* belongs to class A.
Original language | English |
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Pages (from-to) | 461-476 |
Number of pages | 16 |
Journal | Journal of Mathematical Analysis and Applications |
Volume | 435 |
Issue number | 1 |
DOIs | |
State | Published - 1 Mar 2016 |
Keywords
- Class A operator
- Composition operator
- Denjoy-Wolff point
- Hyponormal operator