title: Symmetries of independent statistical observables for ultrametric populations
abstract: When N=2(G), random data X(i), i=1,ellipsis,N show ultrametric covariations, represented by a binary tree, decorrelated observables are defined by a covariance matrix diagonalization. Eigenvalue degeneracies lead one to regroup such observables into eigenprojectors. Symmetries of such projectors are discussed. Such symmetries and degeneracies influence the robustness of the corresponding measurements under random permutations of data.
authors.affiliation: Service de Physique Theorique, Centre d'Etudes de Saclay, 91191 Gif/Yvette, France.
authors.initials: BG
authors.lastname: Giraud