English

Eigenvalue analysis of the Lax operator for the one-dimensional cubic nonlinear defocusing Schr\"odinger equation

Analysis of PDEs 2023-02-02 v2

Abstract

We characterize the location and number of eigenvalues for the Lax operator associated to the one-dimensional cubic nonlinear defocusing Schr\"odinger equation. With the help of a newly discovered unitary matrix, the analysis reduces to the study of the spectral problem for a unitarily equivalent operator, which involves only the amplitude and the phase velocity of the potential. Examples of potentials with special amplitude and phase velocity are investigated.

Keywords

Cite

@article{arxiv.2207.05186,
  title  = {Eigenvalue analysis of the Lax operator for the one-dimensional cubic nonlinear defocusing Schr\"odinger equation},
  author = {Xian Liao and Michael Plum},
  journal= {arXiv preprint arXiv:2207.05186},
  year   = {2023}
}

Comments

The number of eigenvalues for more general cases is characterized. Some interesting examples of potentials with piecewise-constant amplitude and phase velocity functions are included