On a completion of prehilbertian spaces.
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Ambrozie, C.-G. (2005)
Portugaliae Mathematica. Nova Série
Christoph Schmoeger (2005)
Extracta Mathematicae
The present paper deals with a question of M. Mbekhta concerning partial isometries on Banach spaces.
D. K. Sen (1980)
Matematički Vesnik
Peter Šemrl (1990)
Studia Mathematica
Dragan S. Đorđević (2002)
Matematički Vesnik
Messirdi, Bekkai, Mortad, Mohammed Hichem (2008)
Banach Journal of Mathematical Analysis [electronic only]
Hari Bercovici (1984/1985)
Mathematische Zeitschrift
Hans-Joachim Petzsche (1988)
Mathematische Annalen
Winfried Schirotzek (1981)
Commentationes Mathematicae Universitatis Carolinae
Robin Harte, Mostafa Mbekhta (1992)
Studia Mathematica
We investigate when a C*-algebra element generates a closed ideal, and discuss Moore-Penrose and commuting generalized inverses.
Zarnadze, D. (2001)
Georgian Mathematical Journal
Teresa Bermúdez, Antonio Martinón (1992)
Extracta Mathematicae
Laura Burlando (2005)
Studia Mathematica
We give several necessary and sufficient conditions in order that a bounded linear operator on a Banach space be nilpotent. We also discuss three necessary conditions for nilpotency. Furthermore, we construct an infinite family (in one-to-one correspondence with the square-summable sequences of strictly positive real numbers) of nonnilpotent quasinilpotent operators on an infinite-dimensional Hilbert space, all the iterates of each of which have closed range. Each of these operators (as well as...
Schmoeger, Christoph (1994)
Portugaliae Mathematica
Mohammad Sal Moslehian (2004)
Archivum Mathematicum
An operator with infinite dimensional kernel is positive iff it is a positive scalar times a certain product of three projections.
Istratescu, Vasile I., Constantin, Gheorghe (1983/1984)
Portugaliae mathematica
Didenko, V., Silbermann, B. (1999)
Zeitschrift für Analysis und ihre Anwendungen
Ivan Dobrakov (1971)
Czechoslovak Mathematical Journal
Vasile ISTRATESCU, Ioana ISTRATESCU (1971)
Mathematische Annalen
M. Mbekhta, V. Müller (1996)
Studia Mathematica
We give a survey of results concerning various classes of bounded linear operators in a Banach space defined by means of kernels and ranges. We show that many of these classes define a spectrum that satisfies the spectral mapping property.
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