Second order parallel tensors on $S$ -manifolds and semi-parallel hypersurfaces of $S$ -space forms

• Date: 2026
• Main Authors: Belkhelfa, M., Mahi, F., Бельхельфа, М., Махи, Ф.
• Format: Article
• Language: English
• Published: Institute of Mathematics, NAS of Ukraine 2026
• Online Access: https://umj.imath.kiev.ua/index.php/umj/article/view/1524
• Journal Title: Ukrains’kyi Matematychnyi Zhurnal

UDC 515.12 We study a second order parallel symmetric tensor in an $\mathcal{S}$-manifold and we deduce that there is no semi-parallel hypersurface in $\mathcal{S}$-space forms $\widetilde{M}^{2n+s}(c)$ with $c\neq s.$