Contractibility of the hyperspace of meager subcontinua, two examples
Submitted: 2024-08-10
|Accepted: 2025-03-10
|Published: 2025-10-01
Copyright (c) 2025 Alejandro Illanes, Diego Alexander Ramírez Angarita

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Downloads
Keywords:
Arc-smooth continuum, Continuum, Contractible, Dendroid, Hyperspace, Meager subcontinuum
Supporting agencies:
Abstract:
Given a metric continuum X, the hyperspace of meager subcontinua of X, denoted by M(X), is the collection of all subcontinua of X with empty interior. Answering questions by Norberto Ordo˜nez, in this paper we construct two dendroids showing that there is no implication between the conditions: (a) X is contractible and (b) M(X) is contractible. We also prove that if X is an arc-smooth continuum, then M(X) is contractible.
References:
J. Camargo, N. Ordoñez and D. Ramírez, On the hyperspace of meager and regular continua, Appl. Gen. Topol. 25, no. 2 (2024), 385-406. https://doi.org/10.4995/agt.2024.20116
J. J. Charatonik, W. J. Charatonik, K. Omiljanowski and J. R. Prajs, Hyperspace retractions for curves, Dissertationes Math. (Rozprawy Mat.) 370 (1997), 34 pp.
J. J. Charatonik and C. Eberhart, On smooth dendroids, Fund. Math. 67 (1970), 297-322. https://doi.org/10.4064/fm-67-3-297-322
J. J. Charatonik and A. Illanes, N-sequences and contractibility in hyperspaces, Houston J. Math. 32, no. 3 (2006), 745-756.
A. Illanes, Two examples concerning hyperspace retraction, Topology Appl. 29, no. 1 (1988), 67-72. https://doi.org/10.1016/0166-8641(88)90058-2
A. Illanes and S. B. Nadler, Jr., Hyperspaces, Fundamentals and recent advances, Monographs and Textbooks in Pure and Applied Math. Vol. 216, Marcel Dekker, Inc. New York and Basel, 1999.
J. B. Fugate, G. R. Gordh, Jr. and L. Lum, On arc-smooth continua, Topology Proc. 2 (1977), 645-656.
T. Mackowiak, Contractible and nonselectible dendroids, Bull Polish. Acad. Sci. Math. 33 (1985), 321-324.
S. B. Nadler, Jr., Hyperspaces of Sets, Monographs and Textbooks in Pure and Applied Math. Vol. 49, Marcel Dekker, Inc., Neq York, N.Y. 1978.
J. A. Naranjo-Murillo, Examples concerning means on dendroids of generalized type N, Topology Appl. 301 (2021), 107532. https://doi.org/10.1016/j.topol.2020.107532
N. Ordoñez, The space of meager subcontinua, Houston J. Math. 46, no. 3 (2020), 821-834.
L. G. Oversteegen, Non-contractibility of continua, Bull. Acad. Polon. Sci. Ser. Sci. Math. Astronom. Phys. 26 (1978), 837-840.




