Relativistic angular momentum

Summary

Relativistic angular momentum is the form of angular momentum used in special relativity. For a particle it is the antisymmetric tensor $M^{\mu\nu} = x^\mu p^\nu - x^\nu p^\mu$, built from its position four-vector $x$ and its four-momentum $p$. Its space-space components are the usual angular momentum $\vec x \times \vec p$, and its time-space components describe the motion of the centre of energy. The total angular momentum tensor of an isolated system is conserved, as a consequence of the invariance of physics under Lorentz transformations.