English

A note on the Akemann-Doner and Farah-Wofsey constructions

Operator Algebras 2017-02-10 v1 Functional Analysis Logic

Abstract

We remove the assumption of the continuum hypothesis from the Akemann-Doner construction of a non-separable CC^*-algebra AA with only separable commutative CC^*-subalgebras. We also extend a result of Farah and Wofsey's, constructing 1\aleph_1 commuting projections in the Calkin algebra with no commutative lifting. This removes the assumption of the continuum hypothesis from a version of a result of Anderson. Both results are based on Luzin's almost disjoint family construction.

Keywords

Cite

@article{arxiv.1602.02429,
  title  = {A note on the Akemann-Doner and Farah-Wofsey constructions},
  author = {Tristan Bice and Piotr Koszmider},
  journal= {arXiv preprint arXiv:1602.02429},
  year   = {2017}
}
R2 v1 2026-06-22T12:45:05.648Z