In differential geometry, an isoparametric function is a function on a Riemannian manifold whose level surfaces are parallel and of constant mean curvatures. They were introduced by Cartan (1938).
See also Isoparametric manifold
References Cartan, Élie (1938), "Familles de surfaces isoparametriques dans les espaces à courbure constante.", Annali di Matematica Pura ed Applicata, Series 4 (in French), 17: 177–191, doi:10.1007/BF02410700
