An explicit example concerning the invariant subspace problem for Banach spaces (Q976561)

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scientific article; zbMATH DE number 5720625
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An explicit example concerning the invariant subspace problem for Banach spaces
scientific article; zbMATH DE number 5720625

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    An explicit example concerning the invariant subspace problem for Banach spaces (English)
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    14 June 2010
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    The invariant subspace problem is whether every bounded linear operator on a nonzero complex Banach space has a nontrivial closed invariant subspace. This problem was answered in the negative by P.\,Enflo and C.\,J.\thinspace Read, independently. \textit{P.\,Enflo} [Acta Math.\ 158, No.\,3--4, 213--313 (1987; Zbl 0663.47003)] constructed an infinite-dimensional separable Banach space \(X\) and a bounded linear operator on \(X\) without nontrivial closed invariant subspaces. \textit{C.\,J.\thinspace Read} [Bull.\ London Math.\ Soc.\ 16, 337--401 (1984; Zbl 0566.47003); ibid.\ 17, 305--317 (1985; Zbl 0574.47006); J.~Lond.\ Math.\ Soc., II.\ Ser.\ 34, 335--348 (1986; Zbl 0664.47006); Proc.\ Lond.\ Math.\ Soc., III.\ Ser.\ 58, No.\,3, 583--607 (1989; Zbl 0686.47010)] also constructed a bounded linear operator on the Banach space \(\ell_1\) without nontrivial closed invariant subspaces. However, those examples do not give any concrete descriptions. The author of this paper gives an explicit description for those examples.
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    Banach space
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    continuous linear operator
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    invariant subspace
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    sufficiently rapidly increasing sequences
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