## Abstract For a graph __G__, we denote by __d__~__G__~(__x__) and κ(__G__) the degree of a vertex __x__ in __G__ and the connectivity of __G__, respectively. In this article, we show that if __G__ is a 3‐connected graph of order __n__ such that __d__~__G__~(__x__) + __d__~__G__~(__y__) + __d__~__
A Degree Sum Condition for the Existence of a Contractible Edge in a κ-Connected Graph
✍ Scribed by Matthias Kriesell
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 184 KB
- Volume
- 82
- Category
- Article
- ISSN
- 0095-8956
No coin nor oath required. For personal study only.
✦ Synopsis
It is known that a noncomplete }-connected graph of minimum degree of at least w 5} 4 x contains a }-contractible edge, i.e., an edge whose contraction yields again a }-connected graph. Here we prove the stronger statement that a noncomplete }-connected graph for which the sum of the degrees of any two distinct vertices is at least 2 w 5 4 }x&1 possesses a }-contractible edge. The bound is sharp and remains valid and sharp if we look only at degree sums at pairs of vertices at distances of one or two, provided that }{7.
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