Global well-posedness and long-time asymptotics of a general nonlinear non-local Burgers Equation

TL;DR

This paper proves global existence, regularity, and long-term behavior of solutions for a nonlinear non-local Burgers equation with positive initial data, extending regularity results and describing asymptotics.

Contribution

It establishes global classical and weak solutions for a broad class of nonlinear non-local Burgers equations with positive initial data, including instant regularization and long-time asymptotics.

Findings

Global classical solutions from smooth data

Weak solutions become instantly smooth

Detailed long-time asymptotic behavior

Abstract

This paper is concerned with the study of a nonlinear non-local equation that has a commutator structure. The equation reads $\partial_t u-F(u) (-\Delta)^{s/2} u+(-\Delta)^{s/2} (uF(u))=0$, $x\in \mathbb{T}^d$, with s $\in$ (0, 1]. We are interested in solutions stemming from periodic positive bounded initial data. The given function $F \in C^\infty (R^+)$ must satisfy $F' > 0$ a.e. on (0, +$\infty$). For instance, all the functions $F (u) = u^n$ with n $\in$ N * are admissible non-linearities. We construct global classical solutions starting from smooth positive data, and global weak solutions starting from positive data in $L^\infty$. We show that any weak solution is instantaneously regularized into $C^\infty$. We also describe the long-time asymptotics of all solutions. Our methods follow several recent advances in the regularity theory of parabolic integro-differential equations.