English

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

General Topology 2014-11-03 v1

Abstract

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.

Keywords

Cite

@article{arxiv.1107.1502,
  title  = {Normal systems over ANR's, rigid embeddings and nonseparable absorbing sets},
  author = {Piotr Niemiec},
  journal= {arXiv preprint arXiv:1107.1502},
  year   = {2014}
}

Comments

26 pages

R2 v1 2026-06-21T18:33:46.162Z