Résumé:
In this manuscript, we are interested in bounded linear operators defined
on infinite-dimensional Hilbert spaces. Our aim is twofold. First, we study
posinormal operators and their properties. Then we illustrate them with
concrete examples such as the Ces`aro operator and composition operators
on the classical Hardy space of the unit disk. Secondly, we try to
generalize the existing results for supraposinormal operators. New results
are gathered in [2].
