Dark solitons on the surface of water

International audienceThe nonlinear Schrödinger equation (NLS) models the evolution dynamics in time and space of weakly nonlinearwater wave trains in finite or infinite depth. In the defocusing regime (finite depth), the NLS admits a family ofsoliton solutions, which describe the strong depression of wave envelopes. These solitons are referred to darksolitons and have been already observed in optics and in Bose-Einstein condensates. We present experimentalresults on gray and black solitons, propagating in a wave flume. Furthermore, we analyze the data and discussthe discrepancies observed with respect to theoretical predictions. The results prove that in the case of weaknonlinearityof the waves, the NLS describes well the dynamics of nonlinear wave packets in finite depth