Gelfand pairs and spherical functions.
Generalisations of some properties of invariant polynomials with matrix arguments
Some extensions of the properties of invariant polynomials proved by Davis (1980), Chikuse (1980), Chikuse and Davis (1986) and Ratnarajah et al. (2005) are given for symmetric and Hermitian matrices.
Generalized Gelfand pairs associated with the Heisenberg group. (Paires de Guelfand généralisées associées au groupe d'Heisenberg.)