Positive Subdefinite Matrices, Generalized Monotonicity, and Linear Complementarity Problems
Jean-Pierre Crouzeix, A. Hassouni, A. Lahlou, Siegfried Schaible · SIAM Journal on Matrix Analysis and Applications · 2000
Positive subdefinite matrices were introduced by Martos to characterize generalized convex quadratic functions. This concept is extended to nonsymmetric matrices. It leads to a study of pseudomonotone matrices and to new characterizations of generalized monotone affine maps. Finally, some properties of linear complementarity problems involving such maps are derived.