Аннотация:
Six-dimensional planar Hermitian submanifolds of Cayley algebra are considered. It is proved that if such a submanifold of the octave algebta satisfies the $U$-Kenmotsu hypersurfaces axiom, then it is Kählerian. It is also proved that a symmetric non-Kählerian Hermitian six-dimensional submanifold of the Ricci type does not admit totally umbilical Kenmotsu hypersurfaces.
Ключевые слова и фразы:six-dimensional planar Hermitian submanifolds of Cayley algebra, almost contact metric structure, Kenmotsu structure, Kählerian manifold, almost Hermitian manifold.