3D incompressible Euler: Geometric formalism and a hypothetical   self-similar flow
  We give a geometric formulation of 3D incompressible Euler that contains the Eulerian and Lagrangian gauges as special cases. In the Lagrangian gauge, incompressible Euler is a real analytic ODE in Banach space; a short proof of this known result is given. We then describe (in a self-contained section) some basic properties of a hypothetical self-similar solution to 3D incompressible Euler. 
Michael Reiterer
math.AP physics.flu-dyn