Two speed TASEP

TL;DR

This paper analyzes the large-time behavior of a two-speed TASEP model on the integer lattice, revealing a new transition process, shock formation, and detailed asymptotic distributions depending on initial conditions and jump rates.

Contribution

It introduces a comprehensive analysis of TASEP with two particle speeds, identifying a new transition process and deriving the shock diffusion coefficient without second class particles.

Findings

Discovered a new transition process in the two-speed TASEP.

Determined the diffusion coefficient of shocks without second class particles.

Analyzed effects of a moving wall on particle dynamics.

Abstract

We consider the TASEP on Z with two blocks of particles having different jump rates. We study the large time behavior of particles' positions. It depends both on the jump rates and the region we focus on, and we determine the complete process diagram. In particular, we discover a new transition process in the region where the influence of the random and deterministic parts of the initial condition interact. Slow particles may create a shock, where the particle density is discontinuous and the distribution of a particle's position is asymptotically singular. We determine the diffusion coefficient of the shock without using second class particles. We also analyze the case where particles are effectively blocked by a wall moving with speed equal to their intrinsic jump rate.