study the Gauss map GG of rotational hypersurface in E^ 4 E 4 with respect to the so-called
Cheng–Yau operator L_ 1 L 1 acting on the functions defined on the hypersurfaces. We
obtain the classification theorem that the only rotational hypersurface with Gauss map GG
satisfying L_ 1 G= AG L 1 G= AG for some 4 * 4 4× 4 matrix AA are the hyperplanes, right
circular hypercones, circular hypercylinders, and hyperspheres.