Aluthge, Ariyadasa; Wang, Derming Putnam’s theorems for \(w\)-hyponormal operators. (English) Zbl 0976.47017 Hokkaido Math. J. 29, No. 2, 383-389 (2000). Summary: Three theorems on hyponormal operators due to Putnam are generalized to apply to the broader class of \(w\)-hyponormal operators. In particular, it is shown that if an operator \(T\) is \(w\)-hyponormal and the spectrum of \(|T^*|\) is not an interval, then \(T\) has a nontrivial invariant subspace. Cited in 4 Documents MSC: 47B20 Subnormal operators, hyponormal operators, etc. 47A10 Spectrum, resolvent 47A15 Invariant subspaces of linear operators Keywords:log hyponormal operators; approximate point spectrum; invariant subspace; \(w\)-hyponormal operators PDFBibTeX XMLCite \textit{A. Aluthge} and \textit{D. Wang}, Hokkaido Math. J. 29, No. 2, 383--389 (2000; Zbl 0976.47017) Full Text: DOI