In this theory, the Einstein field equation:formula_32where formula_33 is the stress–energy tensor describing the amount and motion of all matter and all nongravitational field energy and momentum, states that the Ricci tensor—or equivalently, the Einstein tensor—represents that part of the gravitational field which is due to the "immediate presence" of nongravitational energy and momentum.
In this theory, the Einstein field equation: formula_31where formula_32 is the stress-energy tensor describing the amount and motion of all matter and all nongravitational field energy and momentum, states that the Ricci tensor—or equivalently, the Einstein tensor—represents that part of the gravitational field which is due to the "immediate presence" of nongravitational energy and momentum.