1. End spaces and tree-decompositions.
- Author
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Koloschin, Marcel, Krill, Thilo, and Pitz, Max
- Subjects
- *
TOPOLOGICAL spaces , *TOPOLOGICAL property , *INTERSECTION graph theory , *TREE graphs - Abstract
We present a systematic investigation into how tree-decompositions of finite adhesion capture topological properties of the space formed by a graph together with its ends. As main results, we characterise when the ends of a graph can be distinguished, and characterise which subsets of ends can be displayed by a tree-decomposition of finite adhesion. In particular, we show that a subset Ψ of the ends of a graph G can be displayed by a tree-decomposition of finite adhesion if and only if Ψ is G δ (a countable intersection of open sets) in | G | , the topological space formed by a graph together with its ends. Since the undominated ends of a graph are easily seen to be G δ , this provides a structural explanation for Carmesin's result that the set of undominated ends can always be displayed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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