Homotopy of unitaries in simple C*-algebras with tracial rank one

dc.creatorLin, Huaxin
dc.date2008-05-05
dc.date2009-05-21
dc.date.accessioned2026-07-07T13:16:37Z
dc.date.available2026-07-07T13:16:37Z
dc.descriptionLet $ε>0$ be a positive number. Is there a number $δ>0$ satisfying the following? Given any pair of unitaries $u$ and $v$ in a unital simple $C^*$-algebra $A$ with $[v]=0$ in $K_1(A)$ for which $$ \|uv-vu\|<\dt, $$ there is a continuous path of unitaries $\{v(t): t\in [0,1]\}\subset A$ such that $$ v(0)=v, v(1)=1 \and \|uv(t)-v(t)u\|<ε\forall t\in [0,1]. $$ An answer is given to this question when $A$ is assumed to be a unital simple $C^*$-algebra with tracial rank no more than one. Let $C$ be a unital separable amenable simple $C^*$-algebra with tracial rank no more than one which also satisfies the UCT. Suppose that $ϕ: C\to A$ is a unital monomorphism and suppose that $v\in A$ is a unitary with $[v]=0$ in $K_1(A)$ such that $v$ almost commutes with $ϕ.$ It is shown that there is a continuous path of unitaries $\{v(t): t\in [0,1]\}$ in $A$ with $v(0)=v$ and $v(1)=1$ such that the entire path $v(t)$ almost commutes with $ϕ,$ provided that an induced Bott map vanishes. Other versions of the so-called Basic Homotopy Lemma are also presented.
dc.description50 pages
dc.identifierhttps://arxiv.org/abs/0805.0583
dc.identifierhttp://arxiv.org/abs/0805.0583
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/230850
dc.subjectOperator Algebras
dc.subjectFunctional Analysis
dc.subject46L35, 46L80
dc.titleHomotopy of unitaries in simple C*-algebras with tracial rank one
dc.typetext

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