Global existence and smoothness for solutions of viscous Burgers equation. (2) The unbounded case: a characteristic flow study
arXiv:1510.01539
Abstract
We show that the homogeneous viscous Burgers equation has a globally defined smooth solution if the initial condition is a smooth function growing like at infinity. The proof relies mostly on estimates of the random characteristic flow defined by a Feynman-Kac representation of the solution. Viscosity independent a priori bounds for the solution are derived from these. The regularity of the solution is then proved for fixed using Schauder estimates. The result extends with few modifications to initial conditions growing abnormally large in regions with small relative volume, separated by well-behaved bulk regions, provided these are stable under the characteristic flow with high probability. We provide a large family of examples for which this loose criterion may be verified by hand.
arXiv comment37 pages