ELA
ISOTROPIC SUBSPACES FOR PAIRS OF HERMITIAN MATRICES
∗LEIBA RODMAN†
Abstract. The maximal dimension of a subspace which is neutral with respect to two hermitian matrices simultaneously, is identified (in many cases) in terms of inertia of linear combinations of the matrices.
Key words. Neutral subspace, Isotropic subspace, Hermitian matrices.
AMS subject classifications.15A57.
∗Received by the editors February 22, 2008. Accepted for publication October 20, 2008 . Handling
Editor: Harm Bart.
†Department of Mathematics, College of William and Mary, Williamsburg, VA 23187-8795, USA
(lxrodm@math.wm.edu). Research was supported in part by NSF grant DMS-0456625.
Electronic Journal of Linear Algebra ISSN 1081-3810 A publication of the International Linear Algebra Society Volume 17, pp. 508-517, October 2008