Piquet, C. Sur L’image numérique d’un opérateur linéaire borné d’un espace de Hilbert. (French) Zbl 0209.15402 C. R. Acad. Sci., Paris, Sér. A 272, 1105-1108 (1971). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page MSC: 47A05 General (adjoints, conjugates, products, inverses, domains, ranges, etc.) 46C05 Hilbert and pre-Hilbert spaces: geometry and topology (including spaces with semidefinite inner product) PDFBibTeX XMLCite \textit{C. Piquet}, C. R. Acad. Sci., Paris, Sér. A 272, 1105--1108 (1971; Zbl 0209.15402)