English

Hamming graphs in Nomura Algebras

Combinatorics 2011-01-14 v2

Abstract

Let A be an association scheme on q\geq 3 vertices. We show that the Bose-Mesner algebra of the generalized Hamming scheme H(n,A), for n\geq 2, is not the Nomura algebra of a type II matrix. This result gives examples of formally self-dual Bose-Mesner algebras that are not the Nomura algebras of type II matrices.

Keywords

Cite

@article{arxiv.1010.1197,
  title  = {Hamming graphs in Nomura Algebras},
  author = {Ada Chan and Akihiro Munemasa},
  journal= {arXiv preprint arXiv:1010.1197},
  year   = {2011}
}

Comments

15 pages, minor revision

R2 v1 2026-06-21T16:24:42.265Z