<oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
<dc:title>AF-embedding of crossed products of AH-algebras by $\mathbb{Z}$ and asymptotic AF-embedding</dc:title>
<dc:creator>Huaxin Lin</dc:creator>
<dc:subject>46L05</dc:subject><dc:subject>46L35</dc:subject><dc:subject>AF-embedding</dc:subject>
<dc:description>Let $A$ be a unital AH-algebra and let $\alpha \in \text{Aut}(A)$ be an automorphism. A necessary condition for $A \rtimes_{\alpha} \mathbb{Z}$ being embedded into a unital simple AF-algebra is the existence of a faithful tracial state. If in addition, there is an automorphism $\kappa$ with $\kappa_{*1} = -\mathrm{id}_{K_1(A)}$ such that $\alpha \mathrel{\circ} \kappa$ and $\kappa \mathrel{\circ} \alpha$ are asymptotically unitarily equivalent, then $A \rtimes_{\alpha} \mathbb{Z}$ can be embedded into a unital simple AF-algebra. Consequently, in the case that $A$ is a unital AH-algebra (not necessarily simple) with torsion $K_1(A)$, $A \rtimes_{\alpha} \mathbb{Z}$ can be embedded into a unital simple AF-algebra if and only if $A$ admits a faithful $\alpha$-invariant tracial state. We also show that if $A$ is a unital $\mathrm{A}\mathbb{T}$-algebra then $A \rtimes_{\alpha} \mathbb{Z}$ can be embedded into a unital simple AF-algebra if and only if $A$ admits a faithful $\alpha$-invariant tracial state. Consequently, for any unital simple $\mathrm{A}\mathbb{T}$-algebra $A$, $A \rtimes_{\alpha} \mathbb{Z}$ can always be embedded into a unital simple AF-algebra.  If $X$ is a compact metric space and $\Lambda: \mathbb{Z}^2 \to \text{Aut}(C(X))$ is a homomorphism, then $C(X) \rtimes_{\Lambda} \mathbb{Z}^2$ can be asymptotically embedded into a unital simple AF-algebra provided that $X$ admits a strictly positive $\Lambda$-invariant probability measure. Consequently $C(X) \rtimes_{\Lambda} \mathbb{Z}^2$ is quasidiagonal if $X$ admits a strictly positive $\Lambda$-invariant Borel probability measure.</dc:description>
<dc:publisher>Indiana University Mathematics Journal</dc:publisher>
<dc:date>2008</dc:date>
<dc:type>text</dc:type>
<dc:format>pdf</dc:format>
<dc:identifier>10.1512/iumj.2008.57.3189</dc:identifier>
<dc:source>10.1512/iumj.2008.57.3189</dc:source>
<dc:language>en</dc:language>
<dc:relation>Indiana Univ. Math. J. 57 (2008) 891 - 944</dc:relation>
<dc:coverage>state-of-the-art mathematics</dc:coverage>
<dc:rights>http://iumj.org/access/</dc:rights>
</oai_dc:dc>