Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-24T13:34:30.342Z Has data issue: false hasContentIssue false

On Countable Dense and n-homogeneity

Published online by Cambridge University Press:  20 November 2018

Jan van Mill*
Affiliation:
Mathematics, VU University Amsterdam, De Boelelaan 1081a, 1081a 1081HV, Netherlands (NL)[email protected]
Rights & Permissions [Opens in a new window]

Abstract.

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We prove that a connected, countable dense homogeneous space is $n$-homogeneous for every n, and strongly 2-homogeneous provided it is locally connected. We also present an example of a connected and countable dense homogeneous space which is not strongly 2-homogeneous. This answers in the negative Problem 136 ofWatson in the Open Problems in Topology Book.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2013

References

[1] Bennett, R., Countable dense homogeneous spaces. Fund. Math. 74 (1972), 189194.Google Scholar
[2] Dijkstra, J. J., Homogeneity properties with isometries and Lipschitz functions. Rocky Mountain J. Math. 40 (2010), 15051525. http://dx.doi.org/10.1216/RMJ-2010-40-5-1505 Google Scholar
[3] Engelking, R., General topology. Second edition. Sigma Ser. Pure Math. 6, Heldermann Verlag, Berlin, 1989.Google Scholar
[4] Fitzpatrick, B., Jr., and Lauer, N. F., Densely homogeneous spaces. I. Houston J. Math. 13 (1987), 1925.Google Scholar
[5] Fitzpatrick, B., Jr., and Zhou, H. X., Some open problems in densely homogeneous spaces. In: Open Problems in Topology, North-Holland Publishing Co., Amsterdam, 1990, 252259.Google Scholar
[6] Kok, H., Connected orderable spaces. Mathematical Centre Tracts 49, Mathematisch Centrum, Amsterdam, 1974.Google Scholar
[7] van Mill, J., A countable dense homogeneous space with a dense rigid open subspace. Fund. Math. 201 (2008), 9198. http://dx.doi.org/10.4064/fm201-1-3 Google Scholar
[8] van Mill, J., On countable dense and strong n-homogeneity. Fund. Math. 214 (2011), 215239.Google Scholar
[9] Saltsman, W. L., Concerning the existence of a connected, countable dense homogeneous subset of the plane which is not strongly locally homogeneous. Topology Proc. 16 (1991), 137176.Google Scholar
[10] Saltsman, W. L., Concerning the existence of a nondegenerate connected, countable dense homogeneous subset of the plane which has a rigid open subset. Topology Proc. 16 (1991), 177183.Google Scholar
[11] Ungar, G. S., Countable dense homogeneity and n-homogeneity. Fund. Math. 99 (1978), 155160.Google Scholar
[12] Ward, A. J., The topological characterisation of an open linear interval. Proc. London Math. Soc. 41 (1936), 191198.Google Scholar
[13] Watson, S., Problems I wish I could solve. In: Open Problems in Topology, North-Holland Publishing Co., Amsterdam, 1990, 3876.Google Scholar
[14] Zamora Avilés, B., Espacios numerablemente densos homogéneos. (Spanish), Master's Thesis, Universidad Michoacana de San Nicholás de Hidalgo, 2003.Google Scholar