Persistence of a Rouse polymer chain under transverse shear flow.

We consider a single Rouse polymer chain in two dimensions in the presence of a transverse shear flow along the x direction and calculate the persistence probability P0(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 P0(t) approximately 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 approximately 0.360+/-0.001.