The paper “Accurate bounds on Lyapunov exponents for expanding maps of the interval“, co-authored by Mark Pollicott (Warwick) and Polina Vytnova, has been published open access (link here) in the Communcations in Mathematical Physics. The paper describes a simple but remarkably effective method for rigorously estimating Lyapunov exponents for expanding maps of the interval. The method is illustrated by application to some standard examples. The first main theorem in the paper is shown in the screenshot below.