Pellegrini, V. J. Numerical range preserving operators on a Banach algebra. (English) Zbl 0314.47002 Stud. Math. 54, 143-147 (1975). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 2 ReviewsCited in 22 Documents MSC: 47A10 Spectrum, resolvent 47C05 Linear operators in algebras 47C10 Linear operators in \({}^*\)-algebras PDF BibTeX XML Cite \textit{V. J. Pellegrini}, Stud. Math. 54, 143--147 (1975; Zbl 0314.47002) Full Text: DOI EuDML OpenURL