Pseudo-distance-regularized graphs are distance-regular or distance-biregular

Autor: Miguel Angel Fiol
Rok vydání: 2012
Předmět:
Zdroj: Linear Algebra and its Applications. 437:2973-2977
ISSN: 0024-3795
DOI: 10.1016/j.laa.2012.07.019
Popis: The concept of pseudo-distance-regularity around a vertex of a graph is a natural generalization, for non-regular graphs, of the standard distance-regularity around a vertex. In this note, we prove that a pseudo-distance-regular graph around each of its vertices is either distance-regular or distance-biregular. By using a combinatorial approach, the same conclusion was reached by Godsil and Shawe-Taylor for a distance-regular graph around each of its vertices. Thus, our proof, which is of an algebraic nature, can also be seen as an alternative demonstration of Godsil and Shawe-Taylor’s theorem.
Databáze: OpenAIRE