Jarzynski Equality — Nonequilibrium Work & Free Energy

⟨W⟩ = — ⟨e^{-βW}⟩ = — ΔF = — Jarzynski error: — Trajectories: 0

Pull speed v: 1.0
Temperature kT: 1.0
Trajectories N: 200
View: Work distribution P(W) Sample trajectories Jarzynski convergence ΔF vs pull speed Run experiment Reset

Jarzynski equality (1997): ⟨e^{-βW}⟩ = e^{-βΔF} — exact free energy from nonequilibrium work measurements, even far from equilibrium! The average work ⟨W⟩ ≥ ΔF (second law), but the exponential average recovers ΔF exactly. Rare low-work trajectories dominate the exponential average.