Published online by Cambridge University Press: 20 November 2018
Consider a Vn with metric tensor gαβ. It is well known that the only tensor containing derivatives of gαβno higher than the second order, linear in the second order derivatives, and having vanishing covariant divergence is the Einstein tensor
(1)
Suppose that a system of ennuple vectors hiαand their inverses hαi is set up at each point of the Vn.