English

Minima Nonblockers and Blocked Sets of a Continuum

General Topology 2023-08-25 v1

Abstract

Given a continuum XX and an element xXx \in X, π(x)\pi(x) is the smallest set that contains xx and does not block singletons, and B(x)B(x) is the set of all elements blocked by x{x}. We prove that for each xXx \in X, B(x)B(x) is connected, B(x)π(x)B(x) \subset \pi(x), and that if B(x)B(x) is closed, then B(x)=π(x)B(x)=\pi(x). Among other results, we prove that if XX is a Kelley continuum and π(x)\pi(x) is proper, then B(x)=π(x)B(x)=\pi(x). Finally, we prove that for a certain class of dendroids, the family of minima non-blockers coincides with the family of connected non-blockers.

Keywords

Cite

@article{arxiv.2306.08897,
  title  = {Minima Nonblockers and Blocked Sets of a Continuum},
  author = {C. Piceno and H. Villanueva},
  journal= {arXiv preprint arXiv:2306.08897},
  year   = {2023}
}

Comments

13 pages, 3 figures, submitted to Topology and its Applications