Hyperspaces of continua with connected boundaries in $\pi$-Euclidean Peano continua

Abstract

Let $X$ be a nondegenerate Peano unicoherent continuum. The family $CB(X)$ of proper subcontinua of $X$ with connected boundaries is a $G_{\delta }$-subset of the hyperspace $C(X)$ of all subcontinua of $X$. If every nonempty open subset of $X$ contains an open subset homeomorphic to ${\mathbb{R}}^n$ (such space is called $\pi$-$n$-Euclidean) and $2\le n<\infty$, then $C(X)\setminus CB(X)$ is recognized as an $F_{\sigma }$-absorber in $C(X)$; if additionally, no one-dimensional subset separates $X$, then the family of all members of $CB(X)$ which separate $X$ is a $D_2(F_{\sigma })$-absorber in $C(X)$, where $D_2(F_{\sigma })$ denotes the small Borel class of differences of two $\sigma$-compacta.

References in corpus (1)

• More absorbers in hyperspaces

Cited by in corpus (1)

• The strong universality of ANRs with a suitable algebraic structure