Kerr horizon angular velocity
= Kerr horizon angular velocity
{c}
{title2=$\Omega_H=a/(r_+^2+a^2)$}
The outer <Killing horizon> of a <Kerr black hole> is generated by $k+\Omega_Hm$, with the stationary <Killing vector field> $k$ normalized at infinity and the axial generator $m$ having $2\pi$-periodic orbits. In <ingoing Kerr coordinates> its generators satisfy $d\chi/dv=\Omega_H$. This is the horizon's angular velocity relative to the nonrotating asymptotic stationary frame.