Article
Keywords:
continuum; property of Kelley; semi-Kelley; cartesian products; hyperspaces; Whitney levels
Summary:
In this paper we construct a Kelley continuum $X$ such that $X\times [0,1]$ is not semi-Kelley, this answers a question posed by J.J. Charatonik and W.J. Charatonik in A weaker form of the property of Kelley, Topology Proc. 23 (1998), 69--99. In addition, we show that the hyperspace $C(X)$ is not semi- Kelley. Further we show that small Whitney levels in $C(X)$ are not semi-Kelley, answering a question posed by A. Illanes in Problemas propuestos para el taller de Teoría de continuos y sus hiperespacios, Queretaro, 2013.
References:
[1] Calderón-Camacho I.D., Castañeda-Alvarado E., Islas-Moreno C., Maya-Escudero D., Ruiz-Montañez F.J.:
Being semi-Kelley does not imply semi-smoothness. Questions Answers Gen. Topology 32 (2014), 73–77.
MR 3222532 |
Zbl 1302.54066
[2] Charatonik J.J.:
Semi-Kelley continua and smoothness. Questions Answers Gen. Topology 21 (2003), 103–108.
MR 1998212 |
Zbl 1041.54031
[3] Charatonik J.J., Charatonik W.J.:
A weaker form of the property of Kelley. Topology Proc. 23 (1998), 69–99.
MR 1743801 |
Zbl 0943.54022
[5] Charatonik W.J.:
On the property of Kelley in hyperspaces. Topology Proc. International Conference, Leningrand 1982, Lectures Notes in Math., 1060, Springer, Berlin, 1984, pp. 7–10.
MR 0770219 |
Zbl 0548.54004
[6] Eberhat C., Nadler S.B., Jr.:
The dimension of certain hyperspaces. Bull. Pol. Acad. Sci., 19 (1971), 1027–1034.
MR 0303513