On stationary points and the complementarity problem

Abstract

Let S be a closed convex cone in Cn, S* the polar cone, g a continuous map from Cn into itself, and e a fixed vector in S*. In this paper we prove that there is a connected set T in S of stationary points of (Dr (e), g) where Dr (e) is the set of all x in S with re(e, x) ≤ r. This extends the results of Lemke and Eaves to the complex nonlinear case and arbitrary closed convex cones in Cn. We show that if g is strictly monotone on S, then T is both unique as well as arcwise connected. This partly solves the open problems raised by Eaves in this more general setting. We also show that if x is a stationary point of (Dr (e), g) and re(e, x) < r then x is a stationary point of (S, g).