Persistence of a Rouse polymer chain under transverse shear flow

TL;DR

This paper studies the persistence probability of a Rouse polymer chain under transverse shear flow, finding a power-law decay with a nontrivial exponent, supported by analytical and numerical results.

Contribution

It provides the first analytical estimate of the persistence exponent for a Rouse chain in shear flow, validated by numerical simulations.

Findings

Persistence decays as a power law with exponent ~0.36

Analytical estimate of the persistence exponent matches simulations

Persistence behavior characterized for shear flow conditions

Abstract

We consider a single Rouse polymer chain in two dimensions in presence of a transverse shear flow along the $x$ direction and calculate the persistence probability $P_0(t)$ that the $x$ coordinate of a bead in the bulk of the chain does not return to its initial position up to time $t$. We show that the persistence decays at late times as a power law, $P_0(t)\sim t^{-\theta}$ with a nontrivial exponent $\theta$. The analytical estimate of $\theta=0.359...$ obtained using an independent interval approximation is in excellent agreement with the numerical value $\theta\approx 0.360\pm 0.001$.