Ding, Xuanhao; Sang, Yuanqi Two questions on products of Hankel operators. (Chinese. English summary) Zbl 1487.47047 Sci. Sin., Math. 51, No. 7, 1151-1162 (2021). Summary: Suppose that \(f, u\) and \(g\) are in the Hardy space of the unit circle \(H^2\), and \(h\) is a square integrable function on the unit circle. \(H_{\bar f}, H_{\bar u}, H_{\bar g}\) and \(H_h\) are Hankel operators which take the Hardy space of the unit circle \(H^2\) into the orthogonal complement of the Hardy space \((H^2)^\bot\). We obtain the necessary and sufficient conditions for \(H_{\bar f} H^*_{\bar u} H_{\bar g} = H_h\) and \(H_{\bar f} H^*_{\bar u} H_{\bar g} = H_{\bar g} H^*_{\bar u} H_{\bar f}\), respectively. Cited in 1 Document MSC: 47B35 Toeplitz operators, Hankel operators, Wiener-Hopf operators 30H10 Hardy spaces Keywords:Hankel operator; Hardy space; product PDFBibTeX XMLCite \textit{X. Ding} and \textit{Y. Sang}, Sci. Sin., Math. 51, No. 7, 1151--1162 (2021; Zbl 1487.47047) Full Text: DOI