English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We study projections in the corona algebra of $C(X)\otimes K$ where$X=[0,1],[0,\infty),(-\infty,\infty)$, and $[0,1]/\{0,1 \}$. Using BDF'sessential codimension, we determine conditions for a projection in the coronaalgebra to be liftable to a projection in the multiplier algebra. Then we alsocharacterize the conditions for two projections to be equal in $K_0$-group,Murray-von Neumann equivalent, unitarily equivalent, and homotopic from theweakest to the strongest. In light of these characterizations, we constructexamples showing that any two equivalence notions do not coincide, which serveas examples of non-stable K-theory of $C\sp*$-algebras.

Homotopy classification of projections in the corona algebra of a non-simple $C\sp *$-algebra