Construction of minimizing travelling waves for the Gross-Pitaevskii equation on $\mathbb{R} \times \mathbb{T}$

TL;DR

This paper constructs and characterizes traveling wave solutions for the Gross-Pitaevskii equation on a product space, revealing when solutions are planar dark solitons or genuinely two-dimensional, using a new symmetrization technique.

Contribution

It introduces a new method to prove the existence of minimizers for the Ginzburg-Landau energy in a periodic setting, identifying conditions for planar versus two-dimensional solutions.

Findings

Minimizers are planar dark solitons for small transverse length.

Genuinely two-dimensional solutions emerge beyond a critical length.

A new symmetrization argument ensures compactness of minimizing sequences.

Abstract

As a sequel to our previous analysis in [9] arXiv:2202.09411 on the Gross-Pitaevskii equation on the product space $\mathbb{R} \times \mathbb{T}$, we construct a branch of finite energy travelling waves as minimizers of the Ginzburg-Landau energy at fixed momentum. We deduce that minimizers are precisely the planar dark solitons when the length of the transverse direction is less than a critical value, and that they are genuinely two-dimensional solutions otherwise. The proof of the existence of minimizers is based on the compactness of minimizing sequences, relying on a new symmetrization argument that is well-suited to the periodic setting.