English

Compact Subsets of the Glimm Space of a $C^*$-algebra

Operator Algebras 2012-03-16 v1

Abstract

If AA is a σ\sigma-unital CC^*-algebra and aa is a strictly positive element of AA then for every compact subset KK of the complete regularization Glimm(A)\mathrm{Glimm}(A) of Prim(A)\mathrm{Prim}(A) there exists α>0\alpha > 0 such that K{GGlimm(A)a+Gα}K\subset \{G\in \mathrm{Glimm}(A) \mid \|a + G\|\geq \alpha\}. This extends a 1974 result of J. Dauns to all σ\sigma-unital CC^*-algebras. However, there is a CC^*-algebra AA and a compact subset of Glimm(A)\mathrm{Glimm}(A) that is not contained in any set of the form {GGlimm(A)a+Gα}\{G\in \mathrm{Glimm}(A) \mid \|a + G\|\geq \alpha\}, aAa\in A and α>0\alpha > 0.

Keywords

Cite

@article{arxiv.1203.3350,
  title  = {Compact Subsets of the Glimm Space of a $C^*$-algebra},
  author = {Aldo J. Lazar},
  journal= {arXiv preprint arXiv:1203.3350},
  year   = {2012}
}

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8 pages