We investigate relationships between inessential operators and improjective operators acting betw... more We investigate relationships between inessential operators and improjective operators acting between Banach spaces X and Y, emphasizing the case in which one of the spaces is a C(K) space. We show that they coincide in many cases, but they are different in the case X = Y = C(K 0), where K 0 is a compact space constructed by Koszmider.
Rendiconti Del Circolo Matematico Di Palermo, 1980
Abstract Viene introdotto il concetto di stato puro in uno spazio ordinato localmente convesso e... more Abstract Viene introdotto il concetto di stato puro in uno spazio ordinato localmente convesso e di Hausdorff, ed è dimostrato un teorema di estensione per tali funzionali. Tale teorema implica tra l'altro che, seB è una sottoalgebra di un'algebra reale di BanachA, ordinata da un cono avente parte interna non vuota, ogni ideale algebrico convesso massimale diB può essere esteso ad
Journal of Mathematical Analysis and Applications, Oct 1, 2000
In this paper we shall consider the relationships between a local version of the Ž . single value... more In this paper we shall consider the relationships between a local version of the Ž . single valued extension property of a bounded operator T g L X on a Banach space X and some quantities associated with T which play an important role in Fredholm theory. In particular, we shall consider some conditions for which T does not have the single valued extension property at a point g C. ᮊ 2000 Academic o Press
ABSTRACT The authors provide a local spectral characterization of the upper and lower semi-Browde... more ABSTRACT The authors provide a local spectral characterization of the upper and lower semi-Browder operators, that is, the upper and lower semi-Fredholm operators with finite ascent or descent. They also study the relationships among the semi-Browder spectra, the essential Kato spectrum, the Weyl spectrum, the surjectivity spectrum and the approximate spectrum for a bounded linear operator having the single valued extension property.
We investigate relationships between inessential operators and improjective operators acting betw... more We investigate relationships between inessential operators and improjective operators acting between Banach spaces X and Y, emphasizing the case in which one of the spaces is a C(K) space. We show that they coincide in many cases, but they are different in the case X = Y = C(K 0), where K 0 is a compact space constructed by Koszmider.
Rendiconti Del Circolo Matematico Di Palermo, 1980
Abstract Viene introdotto il concetto di stato puro in uno spazio ordinato localmente convesso e... more Abstract Viene introdotto il concetto di stato puro in uno spazio ordinato localmente convesso e di Hausdorff, ed è dimostrato un teorema di estensione per tali funzionali. Tale teorema implica tra l'altro che, seB è una sottoalgebra di un'algebra reale di BanachA, ordinata da un cono avente parte interna non vuota, ogni ideale algebrico convesso massimale diB può essere esteso ad
Journal of Mathematical Analysis and Applications, Oct 1, 2000
In this paper we shall consider the relationships between a local version of the Ž . single value... more In this paper we shall consider the relationships between a local version of the Ž . single valued extension property of a bounded operator T g L X on a Banach space X and some quantities associated with T which play an important role in Fredholm theory. In particular, we shall consider some conditions for which T does not have the single valued extension property at a point g C. ᮊ 2000 Academic o Press
ABSTRACT The authors provide a local spectral characterization of the upper and lower semi-Browde... more ABSTRACT The authors provide a local spectral characterization of the upper and lower semi-Browder operators, that is, the upper and lower semi-Fredholm operators with finite ascent or descent. They also study the relationships among the semi-Browder spectra, the essential Kato spectrum, the Weyl spectrum, the surjectivity spectrum and the approximate spectrum for a bounded linear operator having the single valued extension property.
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Papers by Pietro Aiena