arXiv 0806.00562008-06math.FA

Descriptive set theoretic methods applied to strictly singular and strictly cosingular operators

G. Androulakis, K. Beanland

英文摘要：

The class of strictly singular operators originating from the dual of a separable Banach space is written as an increasing union of $ω_1$ subclasses which are defined using the Schreier sets. A question of J. Diestel, of whether a similar result can be stated for strictly cosingular operators, is studied.

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