6 research outputs found

    Functor of continuation in Hilbert cube and Hilbert space

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    A ZZ-set in a metric space XX is a closed subset KK of XX such that each map of the Hilbert cube QQ into XX can uniformly be approximated by maps of QQ into XKX \setminus K. The aim of the paper is to show that there exists a functor of extension of maps between ZZ-sets of QQ [or l2l_2] to maps acting on the whole space QQ [resp. l2l_2]. Special properties of the functor are proved.Comment: 9 page

    Normal systems over ANR's, rigid embeddings and nonseparable absorbing sets

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    Most of results of Bestvina and Mogilski [\textit{Characterizing certain incomplete infinite-dimensional absolute retracts}, Michigan Math. J. \textbf{33} (1986), 291--313] on strong ZZ-sets in ANR's and absorbing sets is generalized to nonseparable case. It is shown that if an ANR XX is locally homotopy dense embeddable in infinite-dimensional Hilbert manifolds and w(U)=w(X)w(U) = w(X) (where `ww' is the topological weight) for each open nonempty subset UU of XX,then XX itself is homotopy dense embeddable in a Hilbert manifold. It is also demonstrated that whenever XX is an AR, its weak product W(X,)={(xn)n=1Xω: xn=for almost alln}W(X,*) = \{(x_n)_{n=1}^{\infty} \in X^{\omega}:\ x_n = * \textup{for almost all} n\} is homeomorphic to a pre-Hilbert space EE with EΣEE \cong \Sigma E. An intrinsic characterization of manifolds modelled on such pre-Hilbert spaces is given.Comment: 26 page
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