Rotating-frame relative effective potential (source code)

= Rotating-frame relative effective potential
{title2=$\psi_{\mathrm{eff}}=\psi+\tfrac12\Omega_b^2R^2$}

For a bar rotating with constant <pattern speed> $\Omega_b$, use $\psi_{\mathrm{eff}}=\psi+\Omega_b^2R^2/2$ in the force convention $+\nabla\psi$. The centrifugal <acceleration> is its added gradient. This is the negative of the usual physical effective potential $\Phi_{\mathrm{eff}}$; Coriolis <acceleration> is separate.