广义相对论的流体解 洛伦兹群 Schutz, Bernard F., 4. Perfect fluids in special relativity, A first course ingeneralrelativity 2, Cambridge University Press, 2009, ISBN 0-521-88705-4
cannot be tensors themselves if the coordinates don't change in a linear way. Ingeneralrelativity, one cannot describe the energy and momentum of the gravitational