PORTUGALIAEMATHEMATICA
Vol. 52, No. 2, pp. 131-138 (1995)
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PORTUGALIAE MATHEMATICA Vol. 52, No. 2, pp. 131-138 (1995) |
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Measures of Weak Noncompactness in Banach Sequence SpacesJozef Banas and Antonio MartinónDepartment of Mathematics, Technical University of Rzeszów,35-959 Rzeszów, W. Pola 2 - POLAND Department of Mathematical Analysis, University of La Laguna, 38271 La Laguna (Tenerife) - SPAIN Abstract: Based on a criterion for weak compactness in the $\ell^p$ product of the sequence of Banach spaces $E_i$, $i = 1, 2, \ldots$, we construct a measure of weak noncompactness in this space. It is shown that this measure is regular but not equivalent to the De Blasi measure of weak noncompactness provided the spaces $E_i$ have the Schur property. Apart from this a formula for the De Blasi measure in the sequence space $c_0(E_i)$ is also derived. Full text of the article:
Electronic version published on: 29 Mar 2001. This page was last modified: 27 Nov 2007.
© 1995 Sociedade Portuguesa de Matemática
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