Displaying similar documents to “A version of Hilbert's 13th problem for infinitely differentiable functions.”

On a class of discontinuous operators in Hilbert spaces

Sebastiano Boscarino (2003)

Commentationes Mathematicae Universitatis Carolinae

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We construct a class of discontinuous operators in infinite-dimensional separable Hilbert spaces, answering a natural question which arises in comparing a fixed point theorem of Altman and Shinbrot ([1], [4]) with its improvement obtained by Ricceri ([2], [3]).