SOliton Gas in Optics and hydrODynamics – SOGOOD

The concept of soliton gas has been introduced at the theoretical level in 1971 as an infinite collection of weakly interacting solitons. In the theoretical construction of a diluted soliton gas, solitons of random amplitudes and velocities are distributed in a non-overlapping way over random positions, like in a classical diluted atomic gas. Until recent experimental observations soliton gases were considered as a purely theoretical model in nonlinear statistical physics.
The overall objective of the SOGOOD project is to build an interdisciplinary approach combining optics, hydrodynamics and numerical simulations to investigate the dynamical, statistical and thermodynamic properties of soliton gas.
The first goal of the SOGOOD project is to demonstrate that soliton gases can be generated in a controlled deterministic way and that they can be clearly observed both in optical and in hydrodynamic experiments. This will unlock the door to the investigation of the validity of the kinetic theory of soliton gas, which represents a question of fundamental importance in nonlinear physics. The second goal of the SOGOOD project is to use the concept of soliton gas to investigate the rôle of coherent structures embedded in two-dimensional turbulent wave fields.
The SOGOOD consortium is composed of four academic groups (PHLAM-Université de Lille, LHEEA-Ecoles Centrale de Nantes, MSC-Université Paris Diderot, LEGI-Université Grnoble-Alpes) having expertise in experiments and numerical simulations of nonlinear propagation of water waves and optical waves.
Two types of experimental platforms: water tanks and optical fibers will be used in a complementary way to achieve these goals. The hydrodynamic data and the optical data will be analyzed by using tool of nonlinear spectral analysis, i. e. by decomposing nonlinear wave fields onto the basis of the nonlinear modes that are intrinsic to the considered wave system. The investigation of the system through nonlinear spectral analysis (instead of conventional Fourier analysis) represents a change in paradigm that will be highly promoted by the SOGOOD project.
The results are expected to be very new and relevant to various communities of researchers, both experimentalists and theoreticians, working in the fields of optics, hydrodynamics, turbulence, mathematical physics but also quantum gases.