## Approximation by invertibles

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- by Michael Gartenberg PDF
- Proc. Amer. Math. Soc.
**61**(1976), 341-346 Request permission

## Abstract:

The uniform closure of the set of invertibles of certain ${C^{\ast }}$-algebras is characterized. It is shown that indices on $\mathcal {G}(C(A))$, where $A$ is a closed annulus in the plane and on $M_2^{{S^2} \times {S^1}}$ have continuous extensions to elements which are not invertible.## References

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## Additional Information

- © Copyright 1976 American Mathematical Society
- Journal: Proc. Amer. Math. Soc.
**61**(1976), 341-346 - MSC: Primary 46L05; Secondary 58D05
- DOI: https://doi.org/10.1090/S0002-9939-1976-0435858-X
- MathSciNet review: 0435858