A finiteness theorem for isoparametric hypersurfaces
It is proved that there are only finitely many diffeomorphism types of compact, isoparametric hypersurfaces in \(S^{n + 1}\) with four distinct principal curvatures. The proof depends on Cheeger's finiteness theorem [see \textit{J. Cheeger}, Am. J. Math. 92, 61-74 (1970; Zbl 0194.529)].
scientific article; zbMATH DE number 663724