On the local maxima of a constrained quadratic form

This note presents a brief and partial review of the work of Broom, Cannings and Vickers 1 Broom, M, Cannings, C and Vickers, GT. 1993. On the number of local maximum of a constrained quadratic form. Proceedings of the Royal Society of London, A443. 1993. pp.573–584.  [Google Scholar]. It also presents some simple examples of an extension of the their formalism to non-symmetric matrices.