Jarzynski 1997: ⟨exp(-βW)⟩ = exp(-βΔF) — non-equilibrium avg recovers equilibrium ΔF

Jarzynski 1997 equality (PRL 78:2690). For a system initially in thermal equilibrium at temperature T, driven arbitrarily far from equilibrium by a time-dependent Hamiltonian protocol λ(t) transforming λ_A → λ_B, the statistical average…