All extensions of \(C^*_r(\mathbb F_n)\) are semi-invertible
\textit{V. Manuilov} [Bull. Lond. Math. Soc. 40, No. 5, 838--844 (2008; Zbl 1159.22002)] conjectured that all extensions of the reduced group \(C^*\)-algebra \(C_r^*({\mathbb F}_2)\) of the free group \({\mathbb F}_2\) by compact operators are semi-invertible. In this paper, the author proves this conjecture for \(C_r^*({\mathbb F}_n)\).
scientific article; zbMATH DE number 5323296