We review some aspects of recent work concerning double scaling limits of singularly perturbed Hermitian random matrix models and their connection to Painlevé equations. We present new results showing how a Painlevé III hierarchy recently proposed by the author can be connected to the Lenard recursion formula used to construct the Painlevé I and II hierarchies.
Atkin, M. (2015). The Lenard recursion relation and a family of singularly perturbed matrix models. Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory, 46(9), 1825-1832. https://doi.org/10.5506/APhysPolB.46.1825 (Original work published 2015)