Gradient flows computing the C-numerical range with applications in NMR spectroscopy
Gradient flows on unitary matrices are studied that maximize the real part of the \(C\)-numerical range of an arbitrary complex \(n\times n\) matrix. A discretization scheme of the gradient flow is presented that converges to the set of critical points of the cost function. A special application is discussed in NMR spectroscopy, where matrices \(C\), \(A\) are nilpotent and the \(C\)-numerical range is a circular disk centered at the origin.
scientific article; zbMATH DE number 1886662