title: Out-of-equilibrium stationary states, percolation, and subcritical instabilities in a fully nonconservative system.
abstract: The exploration of the phase diagram of a minimal model for barchan fields leads to the description of three distinct phases for the system: stationary, percolable, and unstable. In the stationary phase the system always reaches an out-of-equilibrium, fluctuating, stationary state, independent of its initial conditions. This state has a large and continuous range of dynamics, from dilute-where dunes do not interact-to dense, where the system exhibits both spatial structuring and collective behavior leading to the selection of a particular size for the dunes. In the percolable phase, the system presents a percolation threshold when the initial density increases. This percolation is unusual, as it happens on a continuous space for moving, interacting, finite lifetime dunes. For extreme parameters, the system exhibits a subcritical instability, where some of the dunes in the field grow without bound. We discuss the nature of the asymptotic states and their relations to well-known models of statistical physics.
authors.affiliation: Laboratoire Matière et Systèmes Complexes (MSC), Université Paris-Diderot, CNRS UMR 7057, F-75205 Paris Cedex 13, France.|CPT, Aix-Marseille Université, Université de Toulon, CNRS, UMR 7332, F-13288, Marseille, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Génois
authors.affiliation: Laboratoire Matière et Systèmes Complexes (MSC), Université Paris-Diderot, CNRS UMR 7057, F-75205 Paris Cedex 13, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Hersen
authors.affiliation: LIPHY, Université Grenoble Alpes and CNRS, F-38000 Grenoble, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Bertin
authors.affiliation: Laboratoire Matière et Systèmes Complexes (MSC), Université Paris-Diderot, CNRS UMR 7057, F-75205 Paris Cedex 13, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Courrech du Pont
authors.affiliation: Laboratoire Matière et Systèmes Complexes (MSC), Université Paris-Diderot, CNRS UMR 7057, F-75205 Paris Cedex 13, France.|HPC Institute (ICI), École Centrale, Nantes, 1 rue de la Noë, F-44300 Nantes, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Grégoire