2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173914We present exact and analytically accurate results for the problem of a flexible polymer chain in shear flow. Under such a flow the polymer tumbles, and the probability distribution of the tumbling times $τ$ of the polymer decays exponentially as $\sim \exp(-ατ/τ_0)$ (where $τ_0$ is the longest relaxation time). We show that for a Rouse chain, this nontrivial constant $α$ can be calculated in the limit of large Weissenberg number (high shear rate) and is in excellent agreement with our simulation result of $α\simeq 0.324$. We also derive exactly the distribution functions for the length and the orientational angles of the end-to-end vector of the polymer.4 pages, 2 figures. Minor changes. Texts differ slightly from the PRL published versionStatistical MechanicsSoft Condensed Mattertext