Outer Lindblad resonance
= Outer Lindblad resonance
{title2=$m(\Omega_\varphi-\Omega_{\mathrm p})=-\Omega_R$}
The $k_R=+1$ <orbital resonance> of an $m$-fold perturbation of a <galactic disk>. For near-circular <stellar orbits>, $\Omega_R$ is the <radial epicyclic frequency>. The harmonic changes <radial action> and azimuthal <angular momentum> in the ratio $\Delta J_R/\Delta J_\varphi=1/m$, so an orbit gaining <angular momentum> gains random radial motion.