A notion of the Cartesian decomposition and P-numerical radius bounds
摘要
In this note, we introduce the notion of P-generalized Cartesian decomposition of operators in a semi-Hilbertian space induced by a positive operator P acting on a Hilbert space. Using this we obtain several generalizations of known P-numerical radius inequalities, which improve on the existing ones. Furthermore, we discuss characterizations for the equality of existing P-numerical radius inequalities.