The Isoparametric Story, a Heritage of Élie Cartan
英文摘要：
In this article, we survey along the historical route the classification of isoparametric hypersurfaces in the sphere, paying attention to the employed techniques in the case of four principal curvatures.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
