theorem critical_damping {ω : ℝ} (hω : 0 < ω) : dampingRatio ω ω = 1 := by simp only [dampingRatio] exact div_self (ne_of_gt hω)
thesis/CESProofs/Dynamics/MultiplierCycles.lean:254
Multiplier-Cycle Duality in a Multi-Sector Economy