|Date: Friday, February 15, 2019
Location: 1084 East Hall (3:00 PM to 4:00 PM)
Title: Thermodynamic bounds on far-from-equilibrium fluctuations and response
Abstract: One of the basic tools used to characterize a physical system is measuring its response to a perturbation. Indeed, response is used to quantify everything from material properties - like conductivity or viscoelasticity - to the efficacy of biomolecular processes. Near thermodynamic equilibrium, linear response theory has proven to be a powerful tool for characterizing response. At its core is the fluctuation-dissipation theorem (FDT), which dictates that the variance of small fluctuations is intimately related to dissipation. However, far from equilibrium no such equality exists. In this talk, I will discuss two new predictions that show that arbitrarily far from equilibrium dissipation still plays a dominant role in shaping fluctuations and response in systems modeled as Markov jump processes. The first uses a large deviation theory analysis to develop a linear-response-like bound that quantifies the trade-off between the variance of current fluctuations and dissipation. Besides its intrinsic allure as a universal relation, I will discuss how this bound can be used to probe the thermodynamic efficiency of mesoscopic heat engines and molecular motors. The second is a collection of thermodynamic equalities and inequalities for nonequilibrium response akin to the FDT that depend on the strength of nonequilibrium driving, which are consequences of the matrix tree theorem expression for the nonequilibrium steady-state distribution. I will show how these predictions can rationalize the energetic requirements of common biological switches.
Speaker: Jordan Horowitz
Institution: University of Michigan
Event Organizer: Charlie Doering email@example.com