Collaborators: Daniel de las Heras, Johannes Renner, Lucas Treffenstädt, Florian Sammüller
I discuss how non-Markovian dynamics arises within power functional theory [1-3] and how memory is related to the relevant functional generator for nonequilibrium forces. Power functional theory is a formally exact variational framework for the description of the nonequilibrium dynamics of many-body systems. An explicit approximation for the memory kernel that occurs in the superadiabatic free power functional is shown to describe a range of physical phenomena in overdamped Brownian dynamics [4], including viscoelasticity under transient shear [5] and the dynamics of the bulk van Hove function of hard spheres [6]. For Molecular Dynamics it is shown that the local acceleration density constitutes together with the density and the current profiles a third relevant kinematic field which is required to understand non-Markovian flow [7].
References
[1] Power functional theory for Brownian dynamics.
M. Schmidt and J. M. Brader, J. Chem. Phys. 138, 214101 (2013).
[2] Power functional theory for Newtonian many-body dynamics.
Matthias Schmidt, J. Chem. Phys. 148, 044502 (2018).
[3] Flow and structure in nonequilibrium Brownian many-body systems.
Daniel de las Heras and Matthias Schmidt, Phys. Rev. Lett. 125, 018001 (2020).
[4] For recent algorithmic progress, see: Adaptive Brownian Dynamics.
Florian Sammüller and Matthias Schmidt (to be published).
[5] Memory-induced motion reversal in Brownian liquids.
Lucas L. Treffenstädt and Matthias Schmidt, Soft Matter 16, 1518 (2020).
[6] Universality in driven and equilibrium hard sphere liquid dynamics.
Lucas L. Treffenstädt and Matthias Schmidt, Phys. Rev. Lett. 126, 058002 (2021).
[7] Shear and bulk acceleration viscosities.
Johannes Renner, Matthias Schmidt, and Daniel de las Heras (to be published).