Antitonicity property of the Moore-Penrose inverse for selfadjoint operators

RESUMO

In this article we study the antitonicity property of the Moore-Penrose inverse in the class of selfadjoint operators, with respect to the Löwner order. For this purpose, we employ different positive decompositions that selfadjoint operators admit. In addition, we relate a weak version of the antitonicity property with Thompson components.