Non-Markovian modeling of non-equilibrium fluctuations and dissipation in active viscoelastic biomatter

TL;DR

This paper develops a generalized Langevin model to describe the non-equilibrium mechanical behavior of active viscoelastic biomatter, capturing power-law responses and energy transfer, and validates it against experimental data.

Contribution

It introduces a novel Hamiltonian-based model that incorporates elastic coupling and non-equilibrium effects in active biomaterials, providing analytical tools for their mechanical analysis.

Findings

Model accurately fits experimental data for red blood cells and actomyosin networks.

Provides physical interpretation of effective active-particle temperature and elastic constants.

Captures power-law viscoelastic response and non-equilibrium energy transfer.

Abstract

Based on a Hamiltonian that incorporates the elastic coupling between a tracer and active particles, we derive a generalized Langevin model for the non-equilibrium mechanical response of active viscoelastic biomatter. Our model accounts for the power-law viscoelastic response of the embedding polymeric network as well as for the non-equilibrium energy transfer between active and tracer particles. Our analytical expressions for the frequency-dependent response function and the positional autocorrelation function agree nicely with experimental data for red blood cells and actomyosin networks with and without ATP. The fitted effective active-particle temperature, elastic constants and effective friction coefficients of our model allow straightforward physical interpretation.