Virial current
= Virial current
{title2=$T^\mu{}_{\mu}=\partial_\mu V^\mu$}
A <virial current> $V^\mu$ represents the <trace> of a conserved <stress-energy tensor> as a divergence. Then the dilation <Noether current> $D^\mu=x_\nu T^{\mu\nu}-V^\mu$ is conserved, since its divergence is $T^\mu{}_{\mu}-\partial_\mu V^\mu$. This establishes <scale invariance>; a traceless <stress-energy tensor improvement> is the extra condition needed for <conformal currents>.