Skip to main content
Log in

On topological Kadec norms

  • Published:
Mathematische Annalen Aims and scope Submit manuscript

Abstract

We present a topological analogue of the classic Kadec Renorming Theorem, as follows. Let be two separable metric topologies on the same set X. We prove that every point in X has an -neighbourhood basis consisting of sets that are -closed if and only if there exists a function φ: X→ℝ that is -lower semi-continuous and such that is the weakest topology on X that contains and that makes φ continuous. An immediate corollary is that the class of almost n-dimensional spaces consists precisely of the graphs of lower semi-continuous functions with at most n-dimensional domains.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Abry, M., Dijkstra, J. J.: Universal spaces for almost n-dimensionality. In preparation

  2. Abry, M., Dijkstra, J. J., van Mill, J.: Sums of almost zero-dimensional spaces. Topology Proc. 29, (2005) to appear

  3. Bessaga, C., Pełczyński, A.: Selected Topics in Infinite-Dimensional Topology. PWN, Warsaw, 1975

  4. Davis, W. J., Johnson, W. B.: A renorming of nonreflexive Banach spaces. Proc. Amer. Math. Soc. 37, 486–488 (1973)

    Google Scholar 

  5. Dijkstra, J. J., van Mill, J.: Homeomorphism groups of manifolds and Erdős space. Electron. Res. Announc. Amer. Math. Soc. 10, 29–38 (2004)

    Google Scholar 

  6. Dijkstra, J. J., van Mill, J.: Erdős space and homeomorphism groups of manifolds. preprint

  7. Dijkstra, J. J., van Mill, J.: Characterizing complete Erdős space. preprint

  8. Dijkstra, J. J., van Mill, J., , J.: Complete Erdős space is unstable. Math. Proc. Cambridge Philos. Soc. 137, 465–473 (2004)

    Google Scholar 

  9. Engelking, R.: Theory of Dimension, Finite and Infinite. Heldermann Verlag, Berlin, 1995

  10. Erdős, P.: The dimension of the rational points in Hilbert space. Ann. of Math. 41, 734–736 (1940)

    Google Scholar 

  11. Kadec, M. I.: On strong and weak convergence. (Russian) Dokl. Akad. Nauk SSSR 122, 13–16 (1958)

    Google Scholar 

  12. Kadec, M. I.: On the connection between weak and strong convergence. (Ukrainian) Dopovidi Akad. Nauk Ukrain. RSR 9, 465–468 (1959)

    Google Scholar 

  13. Kawamura, K., Oversteegen, L. G., Tymchatyn, E. D.: On homogeneous totally disconnected 1-dimensional spaces. Fund. Math. 150, 97–112 (1996)

    Google Scholar 

  14. Kechris, A. S.: Classical Descriptive Set Theory. Springer Verlag, New York, 1995

  15. Levin, M., Pol, R.: A metric condition which implies dimension ≤ 1. Proc. Amer. Math. Soc. 125, 269–273 (1997)

    Google Scholar 

  16. Levin, M., Tymchatyn, E. D.: On the dimension of almost n-dimensional spaces. Proc. Amer. Math. Soc. 127, 2793–2795 (1999)

    Google Scholar 

  17. Mayer, J. C., Mohler, L. K., Oversteegen, L. G., Tymchatyn, E. D.: Characterization of separable metric ℝ-trees. Proc. Amer. Math. Soc. 115, 257–264 (1992)

    Google Scholar 

  18. Oversteegen, L. G., Tymchatyn, E. D.: On the dimension of certain totally disconnected spaces. Proc. Amer. Math. Soc. 122, 885–891 (1994)

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Mohammad Abry.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Abry, M., Dijkstra, J. On topological Kadec norms. Math. Ann. 332, 759–765 (2005). https://doi.org/10.1007/s00208-005-0651-5

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00208-005-0651-5

Mathematics Subject Classification (2000)

Navigation