It has an electromagnetic portion which can be expressed as a function of the electromagnetic field tensor.
The conservation law for this quantity depends on whether the context is special or general relativity, as in the former situation the divergence is 0, and by Noether's theorem, the translation symmetries imply this conserved current. While it is generally symmetric, this is not true if the spin tensor is nonzero. In general relativity, where the conservation law is more complicated, there is a relation between it and another quantity which is a nonlinear function of the metric and which satisfies the Bianchi identity. It has an electromagnetic portion which can be expressed as a function of the electromagnetic field tensor. It is a relativistic generalization of a quantity from mechanics that is graphically represented as Mohr's circle, expresses the internal force per area of surface on which the force acts, and whose eigenvalues are called principle stresses. For 10 points, name this quantity which appears in the Einstein field equations as proportional to the Einstein tensor, is defined as the flux of generalized momenta through spacetime, and which causes and determines the way spacetime curves.
The conservation law for this quantity depends on whether the context is special or general relativity, as in the former situation the divergence is 0, and by Noether's theorem, the translation symmetries imply this conserved current.
stress-energy tensor