Joint probability densities of an active particle coupled to two heat reservoirs

TL;DR

This paper derives a modified Fokker-Planck equation for an active particle interacting with two heat reservoirs, providing solutions for various topologies and analyzing super-diffusive and diffusive behaviors in different time regimes.

Contribution

It introduces an altered Fokker-Planck framework for active particles coupled to heat reservoirs and solves for joint distributions across multiple topologies with correlated Gaussian forces.

Findings

Super-diffusion in short-time behavior

Gaussian distribution in long-time behavior

Approximate calculations of kurtosis and correlation coefficients

Abstract

We derive a Fokker-Planck equation for joint probability density for an active particle coupled two heat reservoirs with harmonic, viscous, random forces. The approximate solution for the joint distribution density of all-to-all and three others topologies is solved, which apply an exponential correlated Gaussian force in three-time regions of correlation time. Mean squared displacement, velocity behaviors in the form of super-diffusion, while the mean squared displacement, velocity has the Gaussian form, normal diffusion. Concomitantly, the Kurtosis, correlation coefficient, and moment from moment equation are approximately and numerically calculated. In this paper, we derive an altered Fokker-Planck equation for an active particle with the harmonic, viscous, and random forces, coupled to two heat reservoirs. We attain the solution for the joint distribution density of our topology, including the center topology, the ring topology, and the chain topology, subject to an exponential correlated Gaussian force. The mean squared displacement and the mean squared velocity behavior as the super-diffusions in the short-time domain and for the characteristic time=0, while those have the Gaussian forms in the long-time domain and for the characteristic time=0. We concomitantly calculate and analyze the non-equilibrium characteristics of the kurtosis, the correlation coefficient, and the moment from the derived moment equation.