TY - JOUR ID - Lo2020 LB - Lo2020 AU - Lo, Ching-on AU - Wai-keung Loh, Anthony TI - Hilbert-Schmidtness of weighted composition operators and their differences on Hardy spaces ST - Hilbert-Schmidtness of weighted composition operators and their differences on Hardy spaces JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2020 VL - 40 IS - 4 SP - 495 EP - 507 DO - https://doi.org/10.7494/OpMath.2020.40.4.495 UR - https://doi.org/10.7494/OpMath.2020.40.4.495 AB - Let \(u\) and \(\varphi\) be two analytic functions on the unit disk \(\mathbb{D}\) such that \(\varphi(\mathbb{D}) \subset \mathbb{D}\). A weighted composition operator \(uC_{\varphi}\) induced by \(u\) and \(\varphi\) is defined on \(H^2\), the Hardy space of \(\mathbb{D}\), by \(uC_{\varphi}f := u \cdot f \circ \varphi\) for every \(f\) in \(H^2\). We obtain sufficient conditions for Hilbert-Schmidtness of \(uC_{\varphi}\) on \(H^2\) in terms of function-theoretic properties of \(u\) and \(\varphi\). Moreover, we characterize Hilbert-Schmidt difference of two weighted composition operators on \(H^2\). KW - weighted composition operators KW - Hardy spaces KW - compact operators KW - Hilbert-Schmidt operators SN - 1232-9274 ER -