Moore-Penrose inverses of Gram matrices leaving a cone invariant in an indefinite inner product space

Abstract

In this paper we characterize Moore-Penrose inverses of Gram matrices leaving a cone invariant in an indefinite inner product space using the indefinite matrix multiplication. This characterization includes the acuteness (or obtuseness) of certain closed convex cones.

Keywords

• Gram matrix
• Moore-Penrose inverse
• acute cone
• Indefinite inner product space
• 46C20
• 15A09