Existence of quasicontinuous selections for the space 2 f R

Ivan Kupka

Mathematica Bohemica (1996)

  • Volume: 121, Issue: 2, page 157-163
  • ISSN: 0862-7959

Abstract

top
The paper presents new quasicontinuous selection theorem for continuous multifunctions F X with closed values, X being an arbitrary topological space. It is known that for 2 with the Vietoris topology there is no continuous selection. The result presented here enables us to show that there exists a quasicontinuous and upper lower -semicontinuous selection for this space. Moreover, one can construct a selection whose set of points of discontinuity is nowhere dense.

How to cite

top

Kupka, Ivan. "Existence of quasicontinuous selections for the space $2^{f R}$." Mathematica Bohemica 121.2 (1996): 157-163. <http://eudml.org/doc/247949>.

@article{Kupka1996,
abstract = {The paper presents new quasicontinuous selection theorem for continuous multifunctions $F X \longrightarrow \mathbb \{R\}$ with closed values, $X$ being an arbitrary topological space. It is known that for $2^\{\mathbb \{R\}\}$ with the Vietoris topology there is no continuous selection. The result presented here enables us to show that there exists a quasicontinuous and upper$\langle $lower$\rangle $-semicontinuous selection for this space. Moreover, one can construct a selection whose set of points of discontinuity is nowhere dense.},
author = {Kupka, Ivan},
journal = {Mathematica Bohemica},
keywords = {continuous multifunction; selection; quasicontinuity; continuous multifunction; selection; quasicontinuity},
language = {eng},
number = {2},
pages = {157-163},
publisher = {Institute of Mathematics, Academy of Sciences of the Czech Republic},
title = {Existence of quasicontinuous selections for the space $2^\{f R\}$},
url = {http://eudml.org/doc/247949},
volume = {121},
year = {1996},
}

TY - JOUR
AU - Kupka, Ivan
TI - Existence of quasicontinuous selections for the space $2^{f R}$
JO - Mathematica Bohemica
PY - 1996
PB - Institute of Mathematics, Academy of Sciences of the Czech Republic
VL - 121
IS - 2
SP - 157
EP - 163
AB - The paper presents new quasicontinuous selection theorem for continuous multifunctions $F X \longrightarrow \mathbb {R}$ with closed values, $X$ being an arbitrary topological space. It is known that for $2^{\mathbb {R}}$ with the Vietoris topology there is no continuous selection. The result presented here enables us to show that there exists a quasicontinuous and upper$\langle $lower$\rangle $-semicontinuous selection for this space. Moreover, one can construct a selection whose set of points of discontinuity is nowhere dense.
LA - eng
KW - continuous multifunction; selection; quasicontinuity; continuous multifunction; selection; quasicontinuity
UR - http://eudml.org/doc/247949
ER -

References

top
  1. R. Engelking R. V. Heath E. Michael, 10.1007/BF01425452, Invent. Math. 6 (1968), 150-158. (1968) MR0244959DOI10.1007/BF01425452
  2. I. Kupka, Quasicontinuous selections for compact-valued multifunctions, Math. Slovaca 43 (1993), 69-75. (1993) Zbl0784.54023MR1216269
  3. I. Kupka, Continuous multifunction from [-1,0] to R having noncontinuous selection, Publ. Math. (Submitted). 
  4. K. Kuratowski, Topologie I, PWN Warszawa, 1952. (1952) 
  5. N. Levine, 10.1080/00029890.1963.11990039, Amer. Math. Monthly 70 (1963), 36-41. (1963) Zbl0113.16304MR0166752DOI10.1080/00029890.1963.11990039
  6. M. Matejdes, Sur les sélecteurs des multifonctions, Math. Slovaca 37 (1987), 111-124. (1987) Zbl0629.54013MR0899022
  7. M. Matejdes, On selections of multifunctions, Math. Bohem. 118 (1993), 255-260. (1993) Zbl0785.54022MR1239120
  8. M. Matejdes, Quasi-continuous and cliquish selections of multifunctions on product spaces, Real Anal. Exchange. To appear. Zbl0782.54019MR1205513
  9. E. Michael, 10.2307/1969615, Ann. of Math. 63 (1956), 361-382. (1956) Zbl0071.15902MR0077107DOI10.2307/1969615
  10. E. Michael, 10.2307/1969603, Ann. of Math. 64 (1956), 562-580. (1956) Zbl0073.17702MR0080909DOI10.2307/1969603
  11. S. B. Nadler, Hyperspaces of sets, Marcel Dekker, Inc., New York and Bassel, 1978. (1978) Zbl0432.54007MR0500811
  12. T. Neubrunn, Quasi-continuity, Real Anal. Exchange H (1988-89), 259-306. (1988) MR0995972
  13. A. Neubrunnová, On certain generalizations of the notion of continuity, Mat. Časopis 23 (1973), 374-380. (1973) MR0339051

NotesEmbed ?

top

You must be logged in to post comments.

To embed these notes on your page include the following JavaScript code on your page where you want the notes to appear.

Only the controls for the widget will be shown in your chosen language. Notes will be shown in their authored language.

Tells the widget how many notes to show per page. You can cycle through additional notes using the next and previous controls.

    
                

Note: Best practice suggests putting the JavaScript code just before the closing </body> tag.