theorem timescale_ratio_eq_rate_ratio {rSlow rFast : ℝ}
(hSlow : 0 < rSlow) (hFast : 0 < rFast) :
timescaleFromRate rSlow / timescaleFromRate rFast =
spectralGapRatio rSlow rFast := by
simp only [timescaleFromRate, spectralGapRatio]
field_simpEndogenous Hierarchy: Why N Levels?