English

Isomorphisms of $AC(\sigma)$ spaces for countable sets

Functional Analysis 2018-10-23 v2

Abstract

It is known that the classical Banach--Stone theorem does not extend to the class of AC(σ)AC(\sigma) spaces of absolutely continuous functions defined on compact subsets of the complex plane. On the other hand, if σ\sigma is restricted to the set of compact polygons, then all the corresponding AC(σ)AC(\sigma) spaces are isomorphic. In this paper we examine the case where σ\sigma is the spectrum of a compact operator, and show that in this case one can obtain an infinite family of homeomorphic sets for which the corresponding function spaces are not isomorphic.

Keywords

Cite

@article{arxiv.1710.09073,
  title  = {Isomorphisms of $AC(\sigma)$ spaces for countable sets},
  author = {Ian Doust and Shaymaa Al-shakarchi},
  journal= {arXiv preprint arXiv:1710.09073},
  year   = {2018}
}

Comments

14 pages. Revised version with slightly expanded introduction. Some minor typos corrected. (To appear in the Proceedings of the 28th IWOTA, in "Operator Theory: Advances and Applications".)

R2 v1 2026-06-22T22:24:55.099Z