Universal thermodynamic bounds on nonequilibrium response with biochemical applications

Near thermodynamic equilibrium, the fluctuation-dissipation theorem provides a robust theoretical and experimental tool to determine the nature of response via spontaneous equilibrium fluctuations. Generalizations of the fluctuation-dissipation theorem for arbitrary perturbations around nonequilibrium steady states have offered fundamental theoretical insight, but often include observables that require detailed system-specific knowledge. Here, we suggest that an alternative fruitful method for characterizing nonequilibrium response is to study specific families of perturbations. For these families, we present equalities and inequalities valid arbitrarily far from equilibrium that constrain the response of nonequilibrium steady states in terms of the strength of nonequilibrium driving. As an illustration, we show how our results rationalize the energetic cost of a common biochemical switch.

"Universal thermodynamic bounds on nonequilibrium response", J. A. Owen, T. R. Gingirch, and J. M. Horowitz, Phys. Rev. X, 10, 011066 (2020).