English

On the Kotani-Last Conjecture for the Dirac Operator

Spectral Theory 2025-09-24 v1 Dynamical Systems

Abstract

We prove a dichotomy of almost periodicity for reflectionless one-dimensional Dirac operators whose spectra satisfy certain geometric conditions, extending work of Volberg--Yuditskii. We also construct a weakly mixing Dirac operator with a non-constant continuous potential whose spectrum is purely absolutely continuous, adapting Avila's argument for continuous Schr\"odinger operators. In particular, we disprove the Kotani--Last conjecture in the setting of one-dimensional Dirac operators.

Keywords

Cite

@article{arxiv.2509.19072,
  title  = {On the Kotani-Last Conjecture for the Dirac Operator},
  author = {Nyah Davis and íris Emilsdóttir and Long Li and Hangqi Liang},
  journal= {arXiv preprint arXiv:2509.19072},
  year   = {2025}
}

Comments

23 pages

R2 v1 2026-07-01T05:52:12.302Z