On linear combinations of generalized projectors
An \(n\times n\) complex matrix \(G\) is called a generalized projector if \(G^2=G^*\), where \(G^*\) denotes the conjugate transpose of \(G\). The authors establish a complete solution to the problem of when a linear combination of two different generalized projectors is also a generalized projector.
scientific article; zbMATH DE number 2105727
scientific article