The paper “Koopman wavefunctions and classical states in hybrid quantum-classical dynamics“, co-authored by Francois Gay-Balmaz (École Normale Supérieure, Paris) and Cesare Tronci, has been accepted for publication in the Journal of Geometric Mechanics. The paper exploits the theory of hybrid quantum-classical wavefunctions to devise a closure model for the coupled dynamics in which both the quantum density matrix and the classical Liouville distribution retain their initial positive sign. A link to the final form arXiv version is here. The figure below, from the paper, shows how several quantities appearing in the paper are interconnected.