Title:
|
$F_\sigma $-absorbing sequences in hyperspaces of subcontinua (English) |
Author:
|
Gladdines, Helma |
Language:
|
English |
Journal:
|
Commentationes Mathematicae Universitatis Carolinae |
ISSN:
|
0010-2628 (print) |
ISSN:
|
1213-7243 (online) |
Volume:
|
34 |
Issue:
|
4 |
Year:
|
1993 |
Pages:
|
729-745 |
. |
Category:
|
math |
. |
Summary:
|
Let $\Cal D$ denote a true dimension function, i.e., a dimension function such that $\Cal D(\Bbb R^n) = n$ for all $n$. For a space $X$, we denote the hyperspace consisting of all compact connected, non-empty subsets by $C(X)$. If $X$ is a countable infinite product of non-degenerate Peano continua, then the sequence $(\Cal D_{\geq n}(C(X)))_{n=2}^\infty$ is $F_\sigma$-absorbing in $C(X)$. As a consequence, there is a homeomorphism $h: C(X)\rightarrow Q^\infty$ such that for all $n$, $h[\{A \in C(X) : \Cal D(A) \geq n+1\}] = B^n \times Q \times Q \times \dots $, where $B$ denotes the pseudo boundary of the Hilbert cube $Q$. It follows that if $X$ is a countable infinite product of non-degenerate Peano continua then $\Cal D_{\geq n}(C(X))$ is an $F_\sigma$-absorber (capset) for $C(X)$, for every $n \geq 2$. Let $\operatorname{dim}$ denote covering dimension. It is known that there is an example of an everywhere infinite dimensional Peano continuum $X$ that contains arbitrary large $n$-cubes, such that for every $k \in \Bbb N$, the sequence $(\operatorname{dim}_{\geq n}(C(X^k)))_{n=2}^\infty$ is not $F_\sigma$-absorbing in $C(X^k)$. So our result is in some sense the best possible. (English) |
Keyword:
|
Hilbert cube |
Keyword:
|
absorbing system |
Keyword:
|
$F_\sigma$ |
Keyword:
|
$F_{\sigma \delta}$ |
Keyword:
|
capset |
Keyword:
|
Peano continuum |
Keyword:
|
hyperspace |
Keyword:
|
hyperspace of subcontinua |
Keyword:
|
covering dimension |
Keyword:
|
cohomological dimension |
MSC:
|
54B20 |
MSC:
|
54F15 |
MSC:
|
54F45 |
MSC:
|
55M10 |
MSC:
|
57N20 |
idZBL:
|
Zbl 0813.57020 |
idMR:
|
MR1263802 |
. |
Date available:
|
2009-01-08T18:07:55Z |
Last updated:
|
2012-04-30 |
Stable URL:
|
http://hdl.handle.net/10338.dmlcz/118630 |
. |
Reference:
|
[1] Bessaga C., Pełczyński A.: Selected topics in infinite-dimensional topology.PWN, Warszawa, 1975. |
Reference:
|
[2] Bing R.H.: Partitioning a set.Bull. Amer. Math. Soc. 55 (1949), 1101-1110. Zbl 0036.11702, MR 0035429 |
Reference:
|
[3] Curtis D.W.: Boundary sets in the Hilbert cube.Top. Appl. 20 (1985), 201-221. Zbl 0575.57008, MR 0804034 |
Reference:
|
[4] Curtis D.W., Nhu N.T.: Hyperspaces of finite subsets which are homeomorphic to $\aleph _0$-dimensional linear metric space.Top. Appl. 19 (1985), 251-260. MR 0794488 |
Reference:
|
[5] Curtis D.W., Michael M.: Boundary sets for growth hyperspaces.Top. Appl. 25 (1987), 269-283. Zbl 0627.54004, MR 0889871 |
Reference:
|
[6] Gladdines H., van Mill J.: Hyperspaces of infinite-dimensional compacta.Comp. Math. 88 (1993), 143-153. Zbl 0830.57013, MR 1237918 |
Reference:
|
[7] Gladdines H.: $F_\sigma $-absorbing sequences in hyperspaces of compact sets.Bull. Pol. Ac. Sci. vol 40 (3) (1992). MR 1401869 |
Reference:
|
[8] Gladdines H., Baars J., van Mill J.: Absorbing systems in infinite-dimensional manifolds.Topology Appl. 50 (1993), 147-182. Zbl 0794.57005, MR 1217483 |
Reference:
|
[9] Dobrowolski T., Rubin L.R.: The hyperspace of infinite-dimensional compacta for covering and cohomological dimension are homeomorphic.preprint, to appear. MR 1267500 |
Reference:
|
[10] Dijkstra J.J., van Mill J., Mogilski J.: The space of infinite-dimensional compact spaces and other topological copies of $(\ell _f^2)^ømega $.Pac. J. Math. 152 (1992), 255-273. MR 1141795 |
. |