The hyperspace of non-cut subcontinua of graphs and dendrites

Abstract

Given a continuum $X$, let $C(X)$ denote the hyperspace of all subcontinua of $X$. In this paper we study the Vietoris hyperspace $N{C}^{\ast }(X)=\{A\in C(X):X\setminus A\text{ is connected}\}$ when $X$ is a finite graph or a dendrite; in particular, we give conditions under which $N{C}^{\ast }(X)$ is compact, connected, locally connected or totally disconnected. Also, we prove that if $X$ is a dendrite and the set of endpoints of $X$ is dense, then $N{C}^{\ast }(X)$ is homeomorphic to the Baire space of irrational numbers.