Regensburg 2025 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 9: Statistical Physics far from Thermal Equilibrium

DY 9.4: Talk

Monday, March 17, 2025, 15:45–16:00, H47

Mean back relaxation for position, densities and others — •Gabriel Knotz and Matthias Krüger — Institute for theoretical physics, Göttingen, Germany

Recently, a so-called mean back relaxation (MBR) has been introduced, which correlates a scalar observable at three time points. The deviation of its long-time value from 1/2 has been shown to be a marker for breakage of time-reversal symmetry for observables with finite mean. We have extended the discussion by introducing a cut off length when evaluating the MBR from trajectories. For Gaussian systems we can derive a relation between MBR and the mean squared displacement and demonstrate that the MBR can be easily applied to stochastic observables like positions and densities. We discuss the application of the density MBR to multi-particle systems.

[1] Gabriel Knotz and Matthias Krüger, Mean back relaxation for position and densities, Phys. Rev. E 110, 044137 (2024)

[2] Till M. Muenker, Gabriel Knotz, Matthias Krüger and Timo Betz, Accessing activity and viscoelastic properties of artificial and living systems from passive measurement, Nature Materials 23, pages 1283*1291 (2024)

Keywords: Detailed balance; Density; Corrleation