Some uses of the field of values in numerical analysis
Michele Benzi · Bollettino Della Unione Matematica Italiana · 2020
Abstract In this expository paper we illustrate the role that the field of values (or numerical range) of a matrix plays in connection with certain problems of numerical analysis. These include the approximation of matrix functions and the convergence of preconditioned Krylov subspace methods for solving large systems of equations arising from the discretization of partial differential equations.