English

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

General Topology 2019-12-06 v1

Abstract

Let XX be a nondegenerate Peano unicoherent continuum. The family CB(X)CB(X) of proper subcontinua of XX with connected boundaries is a GδG_\delta-subset of the hyperspace C(X)C(X) of all subcontinua of XX. If every nonempty open subset of XX contains an open subset homeomorphic to Rn\mathbb R^n (such space is called π\pi-nn-Euclidean) and 2n<2\le n<\infty, then C(X)CB(X)C(X)\setminus CB(X) is recognized as an FσF_\sigma-absorber in C(X)C(X); if additionally, no one-dimensional subset separates XX, then the family of all members of CB(X)CB(X) which separate XX is a D2(Fσ)D_2(F_\sigma)-absorber in C(X)C(X), where D2(Fσ)D_2(F_\sigma) denotes the small Borel class of differences of two σ\sigma-compacta.

Keywords

Cite

@article{arxiv.1806.10691,
  title  = {Hyperspaces of continua with connected boundaries in $\pi$-Euclidean Peano continua},
  author = {Paweł Krupski},
  journal= {arXiv preprint arXiv:1806.10691},
  year   = {2019}
}