title: Observation of star-shaped surface gravity waves.
abstract: We report a new type of standing gravity wave of large amplitude, having alternatively the shape of a star and of a polygon. This wave is observed by means of a laboratory experiment by vertically vibrating a tank. The symmetry of the star (i.e., the number of branches) is independent of the container form and size, and can be changed according to the amplitude and frequency of the vibration. We show that a nonlinear resonant coupling between three gravity waves can be envisaged to trigger the observed symmetry breaking, although more complex interactions certainly take place in the final periodic state.
authors.affiliation: Laboratoire de Physique de la Matière Condensée (CNRS UMR 7336) Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2, France. Jean.Rajchenbach@unice.fr
authors.forename: Jean
authors.initials: J
authors.lastname: Rajchenbach
authors.forename: Didier
authors.initials: D
authors.lastname: Clamond
authors.forename: Alphonse
authors.initials: A
authors.lastname: Leroux