pub fn compton_equilibrium_ratio(x_grid: &[f64], n: &[f64]) -> f64Expand description
Compute the Compton equilibrium temperature ratio T_e^eq / T_z from the photon spectrum.
T_e^eq = (I₄ / (4 G₃)) T_z where I₄ = ∫x⁴ n(1+n) dx, G₃ = ∫x³ n dx. For a Planck spectrum, T_e^eq = T_z exactly.