  We study the long-time behavior of infinite-energy solutions to the
incompressible Navier-Stokes equations in a two-dimensional exterior domain,
with no-slip boundary conditions. The initial data we consider are
finite-energy perturbations of a smooth vortex with small circulation at
infinity, but are otherwise arbitrarily large. Using a logarithmic energy
estimate and some interpolation arguments, we prove that the solution
approaches a self-similar Oseen vortex as $t \to \infty$. This result was
obtained in collaboration with Yasunori Maekawa (Kobe University).
