The distribution function inequality and products of Toeplitz operators and Hankel operators
A sufficient condition and a necessary condition are obtained for the boundedness of the product of two Hankel operators. An elementary necessary and sufficient condition for the product of two Toeplitz operators to be a compact perturbation of a Toeplitz operator is obtained.
compact perturbation of a Toeplitz operator
scientific article; zbMATH DE number 908035