On the Direct Cauchy Theorem in Widom Domains: Positive and Negative Examples
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 $E$ such that the Direct Cauchy Theorem (DCT) holds in the Widom domain $\bbC\setminus E$. On the other hand we demonstrate that the weak homogeneity condition on $E$ (introduced recently by Poltoratski and Remling) does not ensure that DCT holds in the corresponding Widom domain.
- Publication:
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arXiv e-prints
- Pub Date:
- July 2010
- DOI:
- arXiv:
- arXiv:1007.4901
- Bibcode:
- 2010arXiv1007.4901Y
- Keywords:
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- Mathematics - Spectral Theory;
- 30F15;
- 47B36;
- 30D15
- E-Print:
- A small mistake in Example 6.4 was corrected