Hadamard matrices and spin models
Using an Hadamard matrix of order \(4n\), a 4-associate amorphous association scheme can be constructed on \(16n^2\) symbols and from the association matrices of that scheme, the author constructed three real and two complex, symmetrical Hadamard matrices of order \(16n^2\). Necessary and sufficient conditions are given for those Hadamard matrices to yield generalized spin models of \textit{Eiichi Bannai} and \textit{Etsuko Bannai} [Pac. J. Math. 170, No. 1, 1-16 (1995; Zbl 0848.05072)].
scientific article; zbMATH DE number 906669