Generalizing Praeger--Xu graphs
Abstract
We uniformly study directed Praeger--Xu graphs and Praeger's generalized family overrightarrowPX(Γ,r,s), without requiring that s| r and Γ is an undirected graph. Assuming that Γ×overrightarrowK2 is connected, we determine the full automorphism group of overrightarrowPX(Γ,r,s) for every r and s, prove connectivity, characterize vertex-transitivity, and give an equivalent criterion for t-arc-transitivity. We also study when overrightarrowPX(Γ,r,s) is a Cayley graph. We also give two applications. First, we give a new family of twin-free connected arc-transitive digraphs of valency $4$ whose vertex stabilizers have exponential growth. We also give a connected regular digraph that is not vertex-transitive but whose direct product with a directed cycle is Cayley.
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BibTeX
@misc{ding2026generalizing,
title = {{Generalizing Praeger--Xu graphs}},
author = {Zhaochen Ding and Ci Xuan Wu},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.35623},
eprint = {2610.35623},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.35623},
}
RIS
TY - UNPB
TI - Generalizing Praeger--Xu graphs
AU - Zhaochen Ding
AU - Ci Xuan Wu
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.35623
UR - https://arxiv.org/abs/2610.35623
AB - We uniformly study directed Praeger--Xu graphs and Praeger's generalized family overrightarrowPX(Γ,r,s), without requiring that s| r and Γ is an undirected graph. Assuming that Γ×overrightarrowK_2 is connected, we determine the full automorphism group of overrightarrowPX(Γ,r,s) for every r and s, prove connectivity, characterize vertex-transitivity, and give an equivalent criterion for t-arc-transitivity. We also study when overrightarrowPX(Γ,r,s) is a Cayley graph. We also give two applications. First, we give a new family of twin-free connected arc-transitive digraphs of valency $4$ whose vertex stabilizers have exponential growth. We also give a connected regular digraph that is not vertex-transitive but whose direct product with a directed cycle is Cayley.
ER -