Microscopic Models for Electron Hydrodynamics*

A novel regime of transport whereby electrons behave like a viscous fluid has been the subject of intense study over the past few years. By using various kinetic and hydrodynamic models, we will study the conditions under which such a regime can be obtained and the experimental signatures one should look for. We will show in particular that the viscous Hall effect is a very useful probe of hydrodynamic effects and that the interplay of restricted geometries and applied magnetic fields leads to extremely rich physics.