Inner Lindblad resonance
= Inner 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 losing <angular momentum> gains random radial motion.