Quickly Proving Diestel's Normal Spanning Tree Criterion
نویسندگان
چکیده
We present two short proofs for Diestel's criterion that a connected graph has normal spanning tree provided it contains no subdivision of countable clique in which every edge been replaced by uncountably many parallel edges.
منابع مشابه
A Simple Existence Criterion for Normal Spanning Trees
Halin proved in 1978 that there exists a normal spanning tree in every connected graph G that satisfies the following two conditions: (i) G contains no subdivision of a ‘fat’ Kא0 , one in which every edge has been replaced by uncountably many parallel edges; and (ii) G has no Kא0 subgraph. We show that the second condition is unnecessary.
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ژورنال
عنوان ژورنال: Electronic Journal of Combinatorics
سال: 2021
ISSN: ['1077-8926', '1097-1440']
DOI: https://doi.org/10.37236/9619