  The main result is that given a generic self-similarly expanding
configuration of 3 point vortices that start sufficiently far out, we can
instead take compactly supported vorticity functions, and the resulting
solution to 2D incompressible Euler will evolve like a nearby point vortex
configuration for all time, with the size of the patches growing at most as
$t^{1/4+\epsilon}$ and the distance between them growing as $\sqrt{t}$.
