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On uniformly locally compact quasi-uniform hyperspaces. (English) Zbl 1051.54023

Summary: We characterize those Tychonoff quasi-uniform spaces \((X,\mathcal {U})\) for which the Hausdorff-Bourbaki quasi-uniformity is uniformly locally compact on the family \(\mathcal {K}_{0}(X)\) of nonempty compact subsets of  \(X\). We deduce, among other results, that the Hausdorff-Bourbaki quasi-uniformity of the locally finite quasi-uniformity of a Tychonoff space  \(X\) is uniformly locally compact on  \(\mathcal {K}_{0}(X)\) if and only if \(X\)  is paracompact and locally compact. We also introduce the notion of a co-uniformly locally compact quasi-uniform space and show that a Hausdorff topological space is \(\sigma \)-compact if and only if its (lower) semicontinuous quasi-uniformity is co-uniformly locally compact. A characterization of those Hausdorff quasi-uniform spaces  \((X,\mathcal {U})\) for which the Hausdorff-Bourbaki quasi-uniformity is co-uniformly locally compact on  \(\mathcal {K}_{0}(X)\) is obtained.

MSC:

54E15 Uniform structures and generalizations
54B20 Hyperspaces in general topology
54D45 Local compactness, \(\sigma\)-compactness

References:

[1] G. Beer: Topologies on Closed and Convex Closed Sets. Mathematics and its Applications, Vol. 268. Kluwer Acad. Publ., , 1993. · Zbl 0792.54008
[2] G. Berthiaume: On quasi-uniformities in hyperspaces. Proc. Amer. Math. Soc. 66 (1977), 335-343. · Zbl 0345.54026 · doi:10.2307/2040957
[3] B. S. Burdick: Local compactness of hyperspaces. Ann. New York Acad. Sci. 704 (1993), 28-33. · Zbl 0828.54021 · doi:10.1111/j.1749-6632.1993.tb52506.x
[4] M. M. Coban: Note sur la topologie exponentielle. Fund. Math. 71 (1971), 27-41. · Zbl 0226.54004
[5] H. H. Corson: The determination of paracompactness by uniformities. Amer. J. Math. 80 (1958), 185-190. · Zbl 0080.15803 · doi:10.2307/2372828
[6] R. Engelking: General Topology. Polish Sci. Publ., Warsaw, 1977. · Zbl 0373.54002
[7] N. R. Howes: Modern Analysis and Topology. University text. Springer-Verlag, New York, 1995.
[8] P. Fletcher and W. F. Lindgren: \(C\)-complete quasi-uniform spaces. Arch. Math. (Basel) 30 (1978), 175-180. · Zbl 0402.54024 · doi:10.1007/BF01226037
[9] P. Fletcher and W. F. Lindgren: Quasi-Uniform Spaces. Marcel Dekker, New York, 1982. · Zbl 0501.54018
[10] H. P. A. Künzi, M. Mršević, I. L. Reilly and M. K. Vamanamurthy: Convergence, precompactness and symmetry in quasi-uniform spaces. Math. Japonica 38 (1993), 239-253. · Zbl 0783.54022
[11] H. P. A. Künzi, S. Romaguera: Left \(K\)-completeness of the Hausdorff quasi-uniformity. Rostock. Math. Kolloq. 51 (1997), 167-176. · Zbl 0880.54018
[12] H. P. A. Künzi, S. Romaguera: Well-quasi-ordering and the Hausdorff quasi-uniformity. Topology Appl. 85 (1998), 207-218. · Zbl 0922.54024 · doi:10.1016/S0166-8641(97)00151-X
[13] H. P. A. Künzi and S. Romaguera: Quasi-metric spaces, quasi-metric hyperspaces and uniform local compactness. Rend. Istit. Mat. Univ. Trieste 30 Suppl. (1999), 133-144. · Zbl 0942.54023
[14] H. P. A. Künzi and C. Ryser: The Bourbaki quasi-uniformity. Topology Proc. 20 (1995), 161-183. · Zbl 0876.54022
[15] E. Michael: Topologies on spaces of subsets. Trans. Amer. Math. Soc. 71 (1951), 152-182. · Zbl 0043.37902 · doi:10.2307/1990864
[16] I. L. Reilly, P. V. Subrahmanyam and M. K. Vamanamurthy: Cauchy sequences in quasi-pseudo-metric spaces. Monatsh. Math. 93 (1982), 127-140. · Zbl 0472.54018 · doi:10.1007/BF01301400
[17] M. D. Rice: A note on uniform paracompactness. Proc. Amer. Math. Soc. 62 (1977), 359-362. · Zbl 0353.54011 · doi:10.2307/2041044
[18] J. Rodríguez-López and S. Romaguera: The relationship between the Vietoris topology and the Hausdorff quasi-uniformity. Topology Appl 124 (2002), 451-464. · Zbl 1020.54017 · doi:10.1016/S0166-8641(01)00252-8
[19] S. Romaguera: On hereditary precompactness and completeness in quasi-uniform spaces. Acta Math. Hungar. 73 (1996), 159-178. · Zbl 0924.54035 · doi:10.1007/BF00058951
[20] S. Romaguera and M. Sanchis: Locally compact topological groups and cofinal completeness. J. London Math. Soc. 62 (2000), 451-460. · Zbl 1023.22003 · doi:10.1112/S0024610700001289
[21] M. A. Sánchez-Granero: Covering axioms, directed GF-spaces and quasi-uniformities. Publ. Math. Debrecen 61 (2002), 357-381. · Zbl 1064.54042
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