No arc-connected treelike continuum is the 2-to-1 image of a continuum
Volume 180 / 2003
Fundamenta Mathematicae 180 (2003), 11-24
MSC: Primary 54C10.
DOI: 10.4064/fm180-1-2
Abstract
In 1940, O. G. Harrold showed that no arc can be the exactly 2-to-1 continuous image of a metric continuum, and in 1947 W. H. Gottschalk showed that no dendrite is a 2-to-1 image. In 2003 we show that no arc-connected treelike continuum is the 2-to-1 image of a continuum.
