Some general quadratic numerical radius inequalities for the off-diagonal parts of $2 ⨉ 2$ block operator matrices
Rongf ng Li, D yu Wu, Alatancang Chen · Operators and Matrices · 2021
In this paper, the elementary properties for the quadratic numerical radius are introduced. Furthermore, some general quadratic numerical radius inequalities for the off-diagonal parts of 2 2 block operator matrices are studied. These inequalities are based on the generalized mixed Schwarz inequality, Young inequality and Jensen inequality.