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2026/108/1-2 (2) — DOI: 10.5486/PMD.2026.10156 — pp. 25-44

Parallel real hypersurfaces in $\mathbb{S}^2\times\mathbb{S}^2$ and $\mathbb{H}^2\times\mathbb{H}^2$ with respect to the $k$-generalized Tanaka—Webster connection

Authors: Zejun Hu Orcid.org link for Zejun Hu and Xiaoge Lu Orcid.org link for Xiaoge Lu

Abstract:

In this paper, we first characterize real hypersurfaces of both the Kähler surfaces $\mathbb{S}^2\times\mathbb{S}^2$ and $\mathbb{H}^2\times\mathbb{H}^2$ such that their shape operators have identical covariant derivatives with respect to the Levi-Civita connection and the $k$-generalized Tanaka—Webster connection for a nonzero $k\in\mathbb{R}$. Then, amongst others, we classify all real hypersurfaces of both $\mathbb{S}^2\times\mathbb{S}^2$ and $\mathbb{H}^2\times\mathbb{H}^2$ whose shape operators are parallel with respect to the $k$-generalized Tanaka—Webster connection.

Keywords: parallel real hypersurface, $\mathbb{S}^2\times\mathbb{S}^2$ and $\mathbb{H}^2\times\mathbb{H}^2$, shape operator, Levi-Civita connection, $k$-generalized Tanaka—Webster connection

Mathematics Subject Classification: 53B25, 53B35, 53C42