Inferring nonequilibrium thermodynamics from tilted equilibrium using information-geometric Legendre transform

Understand

Nonstationary thermodynamic quantities depend on the full details of nonstationary probability distributions, making them difficult to measure directly in experiments and numerics.

• We propose a method to infer thermodynamic quantities in relaxation processes by measuring only a few observables, using additional information obtained from measurements in tilted equilibrium, i.e., equilibrium with external fields applied.
• Our method is applicable to arbitrary classical stochastic systems, possibly underdamped, that relax to equilibrium.
• The method allows us to compute the exact value of the minimum entropy production (EP) compatible with the nonstationary observations, giving a tight lower bound on the true EP.