English

On the Direct Cauchy Theorem in Widom Domains: Positive and Negative Examples

Spectral Theory 2010-09-01 v2

Abstract

We discuss several questions which remained open in our joint work with M. Sodin "Almost periodic Jacobi matrices with homogeneous spectrum, infinite-dimensional Jacobi inversion, and Hardy spaces of character--automorphic functions". In particular, we show that there exists a non-homogeneous set EE such that the Direct Cauchy Theorem (DCT) holds in the Widom domain \bbCE\bbC\setminus E. On the other hand we demonstrate that the weak homogeneity condition on EE (introduced recently by Poltoratski and Remling) does not ensure that DCT holds in the corresponding Widom domain.

Keywords

Cite

@article{arxiv.1007.4901,
  title  = {On the Direct Cauchy Theorem in Widom Domains: Positive and Negative Examples},
  author = {Peter Yuditskii},
  journal= {arXiv preprint arXiv:1007.4901},
  year   = {2010}
}

Comments

A small mistake in Example 6.4 was corrected; some other minor modifications

R2 v1 2026-06-21T15:54:00.568Z