We obtain estimates for the essential norm of the composition operators acting on the general spaces of Hardy spaces. Our characterization is given in terms of generalized Nevanlinna counting functions.
"Essential norm of the composition operators on the general spaces of Hardy spaces." Ann. Funct. Anal. 9 (2) 180 - 189, May 2018. https://doi.org/10.1215/20088752-2017-0037