The P 3 -graph of a finite simple graph G is the graph whose vertices are the 3-vertex paths of G, with adjacency between two such paths whenever their union is a 4-vertex path or a 3-cycle. In this paper we show that connected finite simple graphs G and H with isomorphic P 3 -graphs are either isom
Isomorphism criterion for monomial graphs
β Scribed by Vasyl Dmytrenko; Felix Lazebnik; Raymond Viglione
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 88 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Let q be a prime power, π½~q~ be the field of q elements, and k,βm be positive integers. A bipartite graph Gβ=βG~q~(k,βm) is defined as follows. The vertex set of G is a union of two copies P and L of twoβdimensional vector spaces over π½~q~, with two vertices (p~1~,βp~2~) β P and [ l~1~,βl~2~] β L being adjacent if and only if p~2~β+βl~2~β=βp____l. We prove that graphs G~q~(k,βm) and G~qβ²~(kβ²,βmβ²) are isomorphic if and only if qβ=βqβ² and {gcdβ(k,βqβββ1), gcdβ(m,βqβββ1)}β=β{gcdβ(kβ²,βqβββ1),gcdβ(mβ²,βqβββ1)} as multisets. The proof is based on counting the number of complete bipartite INFgraphs in the graphs. Β© 2005 Wiley Periodicals, Inc. J Graph Theory 48: 322β328, 2005
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