Invariant Gibbs dynamics for two-dimensional fractional wave equations in negative Sobolev spaces

Abstract

We consider a fractional nonlinear wave equations (fNLW) with a general power-type nonlinearity, on the two-dimensional torus. Our main goal is to construct invariant global-in-time Gibbs dynamics for a renormalized fNLW. We first construct the Gibbs measure associated with this equation by using the variational approach of Barashkov and Gubinelli. We then prove almost sure local well-posedness with respect to Gibbsian initial data, by exploiting the second order expansion. Finally, we extend solutions globally in time using Bourgain's invariant measure argument.

31 pages. The well-posedness results were improved compared to the first version. The paper was restructured. Most proofs were restructured and rendered more efficient