Christophe Gissinger
Associate professor at Ecole Normale Superieure (ENS Paris)
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Research interests

My research focus on non-linear and statistical physics, mostly within the framework of fluid mechanics. In particular, my current research interests lie in the field of magnetohydrodynamics, i.e. the study of the dynamics of electrically conducting fluids. I combine laboratory experiments, theory and numerical simulations to study various phenomena such as flow instabilities, magnetic field generation, dynamical systems, chaos, pipe flows and turbulence. Below are some typical examples of my current interests:

  • Dynamo action

  • Magnetism of planets, stars and galaxies is due to the self generation of a magnetic field by the turbulent motion of an electrically conducting fluid. But what are exactly the mechanisms of the field generation? What determines the complex dynamics of the field, like periodic oscillations or chaotic field reversals and what is the role of turbulence? etc > more details here...

  • Electromagnetically driven flows

  • Plasmas and liquid metals can be put in motion by Lorentz forces, rather than driven by pressure gradients or mechanical impellers. This new situation can lead to very complex behaviors and rise fundamental questions. For instance, an electromagnetic force due to a travelling magnetic field can produce magnetic field expulsion and cause a stalling of the flow, similarly to an asynchronous motor. The mechanism for such a destabilization is not fully understood, but becomes of primary interest in many industrial situations. A similar mechanism could be involved in the oceanic motions of Jovian moons. > more details here...

  • Chaos and nonlinear dynamics

  • In several physical problems, a modelization using a few coupled differential equations is very useful to understand the non-linear dynamics of complex systems. I am interested in fluids dynamics situations in which a low dimensional behavior is observed, despite the apparently large number of degrees of freedom. It is still unclear why and how some very complex and turbulent systems can be correctly reproduced by extremely simple models. > more details here...

  • MRI

  • The MagnetoRotational Instability (MRI) is a fluid instability arising in MHD flows when the angular velocity decreases outward and a magnetic field is applied. It is currently the best candidate to explain angular momentum transport in accretion disks around stars and black holes. Despite its simplicity, several theoretical aspects of this instability are still poorly known, like for instance the mechanisms of saturation of the MRI. > more details here...