Asymptotic stability of sharp fronts: Analysis and rigorous computation

TL;DR

This paper establishes the asymptotic stability of sharp traveling fronts in nonlinear diffusive-dispersive equations, using analytical and computer-assisted methods, with conditions applicable to a broad class of equations including the KdVB.

Contribution

It provides a new analytical framework for stability analysis of sharp fronts and introduces a computer-assisted proof for specific parameter ranges.

Findings

Stability depends on the spectral property of an auxiliary Schrödinger equation.

Analytical conditions for stability are verified for the KdVB equation within a certain parameter interval.

Computer-assisted proof extends stability results to a wider parameter range.

Abstract

We investigate the stability of traveling front solutions to nonlinear diffusive-dispersive equations of Burgers type, with a primary focus on the Korteweg-de Vries-Burgers (KdVB) equation, although our analytical findings extend more broadly. Manipulating the temporal modulation of the translation parameter of the front and employing the energy method, we establish asymptotic, nonlinear, and orbital stability, provided that an auxiliary Schr\"odinger equation possesses precisely one bound state. Notably, our result is independent of the monotonicity of the profile and does not necessitate the initial condition to be close to the front. We identify a sufficient condition for stability based on a functional that characterizes the 'width' of the traveling wave profile. Analytical verification for the KdVB equation confirms that this sufficient condition holds for the relative dispersion parameter within an open interval $\nu \in [-0.25,0.25]$, encompassing all monotone profiles. Utilizing validated numerics or rigorous computation, we present acomputer-assisted proof demonstrating that the stability condition itself holds for parameter values within the interval [0.2533, 3.9].