SKM 2023 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 27: Statistical Physics: Far From Equilibrium I

DY 27.11: Talk

Wednesday, March 29, 2023, 12:30–12:45, ZEU 250

A nonlinear fluctuation-dissipation theorem for Markovian systems — •Benjamin Lindner^1,2, Kirsten Engbring², Dima Boriskovsky³, and Yael Roichman³ — ¹Bernstein Center for Computational Neuroscience Berlin, Philippstr.\ 13, Haus 2, 10115 Berlin, Germany — ²Physics Department of Humboldt University Berlin, Newtonstr.\ 15, 12489 Berlin, Germany — ³The Raymond and Beverley School of Physics \& Astronomy and The Raymond and Beverley School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel

Fluctuation-Dissipation-Theorems (FDT) connect the internal spontaneous fluctuations of a system with its response to an external perturbation. In this work we propose a new nonlinear fluctuation-dissipation theorem as a test for Markovianity. Previously suggested FDTs are based on linear response and require a significant amount of measurements. However, the nonlinear relation holds for systems out of equilibrium, and for strong perturbations requiring significantly less data than the standard linear relation. We verify the nonlinear theorem for two theoretical model systems: a Brownian particle in a tilted periodic potential, and a harmonically bound particle. In addition, we apply our formalism and test for Markovianity in an inherently out of equilibrium experimental system, based on self-propelled agents.