Stress-energy current from a Killing vector
= Stress-energy current from a Killing vector
{title2=$J^a=T^a{}_bK^b$}
If $T^{ab}$ is symmetric and covariantly conserved and $K$ is a <Killing vector field>, then $J^a=T^a{}_bK^b$ is conserved. Its flux through a spacelike hypersurface is the energy or momentum charge generated by the isometry.