The perfect matching association scheme

Abstract

We revisit the Bose-Mesner algebra of the perfect matching association scheme. Our main results are: 1. An inductive algorithm, based on solving linear equations, to compute the eigenvalues of the orbital basis elements given the central characters of the symmetric groups. 2. Universal formulas, as content evaluations of symmetric functions, for the eigenvalues of fixed orbitals. 3. An inductive construction of an eigenvector (the so called first Gelfand-Tsetlin vector) in each eigenspace leading to a different inductive algorithm (not using central characters) for the eigenvalues of the orbital basis elements.