Designs, Codes and Cryptography

, Volume 65, Issue 1–2, pp 55–63 | Cite as

A relationship between the diameter and the intersection number c 2 for a distance-regular graph

  • Jack H. Koolen
  • Jongyook Park


In this paper we will look at the relationship between the intersection number c 2 and the diameter of a distance-regular graph. We also give some tools to show that a distance-regular graph with large c 2 is bipartite, and a tool to show that if k D is too small then the distance-regular graph has to be antipodal.


Distance-regular graphs Intersection numbers Hadamard graphs Hypercubes Diameter 

Mathematics Subject Classification (2000)



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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.Department of MathematicsPOSTECHPohangSouth Korea

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