SFB 303 Discussion Paper No. B - 134

Author: Neumann, Michael, and Hans Joachim Werner
Title: Nonnegative Group Inverses
Abstract: For a nonnegative block lower triangular matrix we characterize when it possesses a nonnegative group inverse and, when it does, we give this inverse an explicit formula. As a consequence we show that a necessary condition for the existence of such an inverse is that the eigenspace of the matrix corresponding to its Perron root is spanned by eigenvectors only. Actually we deduce a stronger result. Namely, that a necessary condition for a nonnegative matrix to have a nonnegative Drazin inverse is that its eigenspace corresponding to its Perron root is spanned by eigenvectors only.
Keywords: Nonnegativity, group inverse, Drazin inverse
JEL-Classification-Number: 210
Creation-Date: 1989
Unfortunately this paper is not available online. Please contact us to order a hardcopy.

SFB 303 Homepage

26.05.1998, Webmaster