Let[Figure not available: see fulltext.] be a self-dual P-polynomial association scheme. Then there are at most 12 diagonal matrices T such that (PT)3 =I. Moreover, all of the solutions for the classical infinite families of such schemes (including the Hamming scheme) are classified.
|Original language||English (US)|
|Number of pages||6|
|Journal||Graphs and Combinatorics|
|State||Published - Jun 1995|