Zero-dispersion limit for the Benjamin-Ono equation on the torus with single well initial data

TL;DR

This paper studies the zero-dispersion limit of the Benjamin-Ono equation on the torus with single well initial data, proving weak convergence to a multivalued Burgers solution and analyzing spectral asymptotics.

Contribution

It establishes the existence and uniformity of the zero-dispersion limit on the torus and connects it to the multivalued Burgers solution, extending previous results to periodic settings.

Findings

Zero-dispersion limit exists in the weak sense on the torus.

Limit equals the signed sum of branches of the multivalued Burgers solution.

Spectral data asymptotics are precisely characterized for cosine initial data.

Abstract

We consider the zero-dispersion limit for the Benjamin-Ono equation on the torus. We prove that when the initial data is a single well, the zero-dispersion limit exists in the weak sense and is uniform on every compact time interval. Moreover, the limit is equal to the signed sum of branches for the multivalued solution of the inviscid Burgers equation obtained by the method of characteristics. This result is similar to the one obtained by Miller and Xu for the Benjamin-Ono equation on the real line for decaying and positive initial data. We also establish some precise asymptotics of the spectral data with the cosine initial data, justifying our approximation method, which is analogous to the work of Miller and Wetzel concerning a family of rational potentials for the Benjamin-Ono equation on the real line.