2D Vortex Motion of an Incompressible Ideal Fluid: The Koopman–von Neumann Approach
Abstract
An incompressible ideal fluid in the two-dimensional torus (i.e. the Euler equation in a rectangle with periodic boundary conditions) is considered. The flow for a vorticity field concentrated in any finite number of points is analyzed. A compound Poisson measure Π, invariant for this flow, is introduced. The Hilbert space ℒ2(Π) and the properties of the corresponding ℒ2-flow are investigated. In particular it is proven that the corresponding generator is Markov unique.