Our book
Mathematics
of Two-Dimensional Turbulence written in
collaboration with
Sergei Kuksin is now published by
Cambridge University
Press. You
can download it
as a
PDF
file or order a copy by clicking
here. Do
not hesitate to contact us if you have any remark.
Abstract
This book is dedicated to the mathematical study of
two-dimensional statistical hydrodynamics and turbulence, described by
the 2D Navier–Stokes system with a random force. The authors' main goal
is to justify the statistical properties of a fluid's velocity field
$u(t,x)$ that physicists assume in their work. They rigorously prove
that $u(t,x)$ converges, as time grows, to a statistical equilibrium,
independent of initial data. They use this to study ergodic properties
of $u(t,x)$ – proving, in particular, that observables $f(u(t,\cdot))$
satisfy the strong law of large numbers and central limit theorem. They
also discuss the inviscid limit when viscosity goes to zero,
normalising the force so that the energy of solutions stays constant,
while their Reynolds numbers grow to infinity. They show that then the
statistical equilibria converge to invariant measures of the 2D Euler
equation and study these measures. The methods apply to other nonlinear
PDEs perturbed by random forces.