English

On Simon's Hausdorff Dimension Conjecture

Spectral Theory 2020-12-02 v1 Classical Analysis and ODEs

Abstract

Barry Simon conjectured in 2005 that the Szeg\H{o} matrices, associated with Verblunsky coefficients {αn}nZ+\{\alpha_n\}_{n\in\mathbb{Z}_+} obeying n=0nγαn2<\sum_{n = 0}^\infty n^\gamma |\alpha_n|^2 < \infty for some γ(0,1)\gamma \in (0,1), are bounded for values zDz \in \partial \mathbb{D} outside a set of Hausdorff dimension no more than 1γ1 - \gamma. Three of the authors recently proved this conjecture by employing a Pr\"ufer variable approach that is analogous to work Christian Remling did on Schr\"odinger operators. This paper is a companion piece that presents a simple proof of a weak version of Simon's conjecture that is in the spirit of a proof of a different conjecture of Simon.

Keywords

Cite

@article{arxiv.2012.00660,
  title  = {On Simon's Hausdorff Dimension Conjecture},
  author = {David Damanik and Jake Fillman and Shuzheng Guo and Darren C. Ong},
  journal= {arXiv preprint arXiv:2012.00660},
  year   = {2020}
}

Comments

9 pages

R2 v1 2026-06-23T20:38:48.202Z