Article
Keywords:
space of continuous maps; Fell topology; hyperspace; metrizable; hypograph; separable; first-countable
Summary:
For a Tychonoff space $X$, let $\downarrow {\rm C}_F(X)$ be the family of hypographs of all continuous maps from $X$ to $[0,1]$ endowed with the Fell topology. It is proved that $X$ has a dense separable metrizable locally compact open subset if $\downarrow {\rm C}_F(X)$ is metrizable. Moreover, for a first-countable space $X$, $\downarrow {\rm C}_F(X)$ is metrizable if and only if $X$ itself is a locally compact separable metrizable space. There exists a Tychonoff space $X$ such that $\downarrow {\rm C}_F(X)$ is metrizable but $X$ is not first-countable.
References:
[1] Beer G.:
Topologies on Closed and Closed Convex Sets. MIA 268, Kluwer Acad. Publ., Dordrecht, 1993.
MR 1269778 |
Zbl 0792.54008
[2] Kelly J.L.:
General Topology. GTM 27, Springer, New York; Reprint of the 1955 ed. published by Van Nostrand, 1955.
MR 0070144
[4] Yang Z.:
The hyperspace of the regions below of continuous maps is homeomorphic to $c_0$. Topology Appl. 153 (2006), 2908–2921.
MR 2248393 |
Zbl 1111.54008
[5] Yang Z., Fan L.:
The hyperspace of the regions below of continuous maps from the converging sequence. Northeast Math. J. 22 (2006), 45–54.
MR 2208621 |
Zbl 1089.54006
[6] Yang Z., Wu N.:
The hyperspace of the regions below of continuous maps from S*S to I. Questions Answers Gen. Topology 26 (2008), 29–39.
MR 2413994
[8] Yang Z., Zhang B.:
The hyperspace of the regions below continuous maps with the Fell topology is homeomorphic to $c_0$. Acta Math. Sinica, English Ser. 28 (2012), 57–66.
DOI 10.1007/s10114-012-0030-6 |
MR 2863750
[10] Zhang Y., Yang Z.:
Hyperspaces of the regions below of upper semi-continuous maps on non-compact metric spaces. Advances in Math. in China 39 (2010), 352–360 (Chinese).
MR 2724454
[11] McCoy R.A., Ntanyu I.:
Properties $ C(X)$ with the epi-topology. Bollettion U.M.I. (7)6-B(1992), 507–532.
MR 1191951