This however does not take into account the specificity
of gravity. Let us consider a spherical region of radius
R. It cannot contain more mass-energy than a black
hole of same size i.e. of Schwarzschild radius RS = R.
Hence, using RS = 2GN M (M mass of black hole), the
energy E in this spherical region satisfies the relation
E < M = R/(2GN). If vacuum energy is gravitating
(which we supposed all along), then, disregarding constants
of order one,