Formula_22738

\[\begin{gathered}c_{0}=R+\left(\pi_{j}\right)^{2}+\pi^{i j} \pi_{i j}-T_{00}=0, \\c_{i}=\nabla_{i} \pi_{j}{ }^{j}-\nabla_{j} \pi_{i}{ }^{j}-\frac{1}{2} T_{0 i}=0,\end{gathered}\]