ISSN : 3059-0604
The study of the integral of the scalar curvature, <TEX>$A(g)\;=\;{\int}_M\;RdV_9$</TEX> as a functional on the set M of all Riemannian metrics of the same total volume on a compact orient able manifold M is now classical, dating back to Hilbert [6] (see also Nagano [8]). Riemannian metric g is a critical point of A(g) if and only if g is an Einstein metric.(omitted)