Modified version of open TASEP with dynamic defects

TL;DR

This paper introduces a modified open TASEP model with dynamic defects affecting particle entry and movement, deriving mean-field equations, analyzing phase diagrams, and validating results with simulations.

Contribution

It proposes a new modification to TASEP where entry is hindered by obstacles, extending previous models and providing analytical and numerical insights.

Findings

Obstacles shift phase boundaries but preserve three phases.

The model converges to standard TASEP as obstacle effect diminishes.

Mean-field solutions agree with Monte Carlo simulations.

Abstract

We propose a modification to the study of site-wise dynamically disordered totally asymmetric simple exclusion process (TASEP). Motivated by the process of gene transcription, a study in ref. \cite{waclaw2019totally} introduced an extension of TASEP, where the defects (or obstacles) bind/un-bind dynamically to the sites of the lattice and the hopping of the particles on lattice faces a hindrance if the arrival site is occupied by an obstacle. In addition, the particle is only allowed to enter the lattice provided the first site is defect-free. In our study, we propose that the particle movement at the entry of the lattice must face an equal hindrance that is provided by the obstacles to the rest of the particles on the lattice. For open boundaries, the continuum mean-field equations are derived and solved numerically to obtain steady-state phase diagrams and density profiles. The presence of obstacles produces a shift in the phase boundaries obtained but the same three phases as obtained for the standard TASEP. Contrary to the model introduced in ref. \cite{waclaw2019totally}, the idea to introduce the modification at the entrance shows that the limiting case $p_d \rightarrow 1$ converges to the standard TASEP, where $p_d$ refers to the affected hopping rate due to presence of obstacle. The mean-field solutions are validated using extensive Monte Carlo simulations.