On a matrix decomposition of Hartwig and Spindelböck
Partial isometries and partial isometries combined with EP matrices are characterized by means of a result on unitary similarity derived by \textit{R. E. Hartwig} and \textit{K. Spindelböck} [Linear Multilinear Algebra 14, 241--256 (1983; Zbl 0525.15006)]. In addition, Hartwig's factorization is also used to study different matrix partial orderings.
scientific article; zbMATH DE number 5552976
scientific article