COMPLEX SYMMETRY OF TOEPLITZ OPERATORS AND COMPOSITION OPERATORS
COMPLEX SYMMETRY OF TOEPLITZ OPERATORS AND COMPOSITION OPERATORS
- 대한수학회
- Bulletin of the Korean Mathematical Society
- Vol.61No.6
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2024.011509 - 1527 (19 pages)
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Denote by H<sub>γ</sub>(𝔻) the Hilbert space of holomorphic functions over the open unit disk 𝔻 with the reproducing kernel $K^{\gamma}_{\omega}(z)={\frac{1}{(1-{\bar{\omega}}z)^{\gamma}}}$, γ > 0. Let $J_{\alpha}:J_{\alpha}f(z)={\overline{f({\overline{{\alpha}z})}}}$ for z ∈ 𝔻 and 𝛼 ∈ 𝜕𝔻, and let W<sub>u,v</sub> be the weighted composition operator. In this paper, we prove that if b ∈ ℝ and $b{\neq}{\frac{k{\pi}}{2}}$, for any integer k, then (cos b+i sin bW<sub>u,v</sub>)J<sub>𝛼</sub> is a conjugation if and only if $v(z)={\frac{c-z}{1-{\bar{c}}z}}$, u(z) = ±k<sup>(γ)</sup><sub>c</sub>(z), c ∈ 𝔻 and ${\bar{c}}\,=\,c{\alpha}$, where k<sup>(γ)</sup><sub>c</sub>(z) is the normalized reproducing kernel, or (cos b + i sin bW<sub>u,v</sub>)J<sub>𝛼</sub> = λJ<sub>𝛼</sub> for some λ ∈ ℂ with |λ| = 1. We then derive a necessary and sufficient condition for a Toeplitz operator to be complex symmetric with respect to the conjugation (cos b + i sin bW<sub>u,v</sub>)J<sub>𝛼</sub> on H<sub>γ</sub>(𝔻) with γ ≥ 1. Similarly, we also conduct a similar study for composition operators on H<sub>γ</sub>(𝔻) with γ > 0.
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