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arXiv · 2412.10233

Nonequilibrium fluctuation-response relations for state observables

Krzysztof Ptaszynski·Timur Aslyamov·Massimiliano Esposito
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Abstract

Time-integrated state observables, which quantify the fraction of time spent by the system in a specific pool of states, are important in many fields, such as chemical sensing or the theory of fluorescence spectroscopy. We derive exact identities, called Fluctuation-Response Relations (FRRs), that connect the fluctuations of such observables to their response to external perturbations in nonequilibrium steady state of Markov jump processes. Using these results, we derive a first known upper bound on fluctuations of state observables, as well as some new lower bounds. We further demonstrate how our identities provide a deeper understanding of the mechanistic origin of fluctuations and reveal their properties dependent only on system topology, which may be relevant for model inference using measured data.

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Krzysztof Ptaszynski, Timur Aslyamov, Massimiliano Esposito. 2024-12-13. Nonequilibrium fluctuation-response relations for state observables. https://doi.org/10.1103/r1qk-76gc

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