Khalagai, J. M.; Otieno, M. O. A. E. On quasiaffinity and quasiaffine inverses of partial isometries. (English) Zbl 1064.47501 Bull. Allahabad Math. Soc. 15, 35-40 (2000). Summary: It is a well-known fact in operator theory that an invertible partial isometry is unitary. In this note, we show that a relaxation of invertibility to the concept of quasiaffine inverse or mere quasiaffinity of a partial isometry will still give us the result that it is unitary. We also deduce results concerning quasi-similarity of partial isometrics. MSC: 47A65 Structure theory of linear operators 47A05 General (adjoints, conjugates, products, inverses, domains, ranges, etc.) Keywords:partial isometry; unitary; invertibility; quasiaffinity; quasi-similarity PDFBibTeX XMLCite \textit{J. M. Khalagai} and \textit{M. O. A. E. Otieno}, Bull. Allahabad Math. Soc. 15, 35--40 (2000; Zbl 1064.47501)