English

E-theory for C[0,1]-algebras with finitely many singular points

Operator Algebras 2013-12-17 v2

Abstract

We study the E-theory group E[0,1](A,B)E_{[0,1]}(A,B) for a class of C*-algebras over the unit interval with finitely many singular points, called elementary C[0,1]C[0,1]-algebras. We use results on E-theory over non-Hausdorff spaces to describe E[0,1](A,B)E_{[0,1]}(A,B) where AA is a sky-scraper algebra. Then we compute E[0,1](A,B)E_{[0,1]}(A,B) for two elementary C[0,1]C[0,1]-algebras in the case where the fibers A(x)A(x) and B(y)B(y) of AA and BB are such that E1(A(x),B(y))=0E^1(A(x),B(y)) = 0 for all x,y[0,1]x,y\in [0,1]. This result applies whenever the fibers satisfy the UCT, their K0K_0-groups are torsion-free and their K1K_1-groups are zero. In that case we show that E[0,1](A,B)E_{[0,1]}(A,B) is isomorphic to Hom(K0(A),K0(B))\text{Hom}(\mathbb{K}_0(A), \mathbb{K}_0(B)), the group of morphisms of the K-theory sheaves of AA and BB. As an application, we give a streamlined partially new proof of a classification result due to the first author and Elliott.

Keywords

Cite

@article{arxiv.1309.0649,
  title  = {E-theory for C[0,1]-algebras with finitely many singular points},
  author = {M. Dadarlat and P. Vaidyanathan},
  journal= {arXiv preprint arXiv:1309.0649},
  year   = {2013}
}

Comments

21 pages