Nearest matrix with two prescribed eigenvalues
Generalizing a result of \textit{A. N. Malyshev} [Numer. Math. 83, 443--454 (1999; Zbl 0972.15011)], the author obtains a formula for the distance (measured in the spectral norm) of a given matrix from the set of matrices whose eigenvalues include two given numbers.
scientific article; zbMATH DE number 2173152