The invarianee ofC-numerical rangeC-numericai radius, and their dual problems
Wai Ypi Man · Linear and Multilinear Algebra · 1991
Let C be an n×n normal matrix. Let For any n×n matrix A, define the C-numerical range and the C-numerical radius of A by and respectively. We give a characierizaiion for those linear operators T which satisfy one of the following properties: .