## Abstract Let $\Gamma$ be a finite __G__βsymmetric graph whose vertex set admits a nontrivial __G__βinvariant partition $\cal B$. It was observed that the quotient graph $\Gamma\_{\cal B}$ of $\Gamma$ relative to $\cal B$ can be (__G__, __2__)βarc transitive even if $\Gamma$ itself is not necessa
A class of symmetric graphs with 2-arc transitive quotients
β Scribed by Bin Jia; Zai Ping Lu; Gai Xia Wang
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 179 KB
- Volume
- 65
- Category
- Article
- ISSN
- 0364-9024
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β¦ Synopsis
Let be an X -symmetric graph admitting an X -invariant partition B on V ( ) such that B is connected and (X , 2)-arc transitive. A characterization of ( , X , B) was given in [S. Zhou Eur J Comb 23 (2002), 741-760] for the case where |B|>| (C)β©B| = 2 for an arc (B, C) of B . We consider in this article the case where |B|>| (C)β©B| = 3, and prove that can be constructed from a 2-arc transitive graph of valency 4 or 7 unless its connected components are isomorphic to 3K 2 , C 6 or K 3,3 . As a byproduct, we prove that each connected tetravalent (X , 2)-transitive graph is either the complete graph K 5 or a near n-gonal graph for some n β₯ 4. α§ 2010 Wiley
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