Characterizing small spheres in a unit sphere by Fischer–Marsden equation

Abstract We use a nontrivial concircular vector field u on the unit sphere S n + 1 $\mathbf{S}^{n+1}$ in studying geometry of its hypersurfaces. An orientable hypersurface M of the unit sphere S n + 1 $\mathbf{S}^{n+1}$ naturally inherits a vector field v and a smooth function ρ. We use the conditio...

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Bibliographic Details
Main Authors: Nasser Bin Turki, Sharief Deshmukh, Gabriel-Eduard Vîlcu
Format: Article
Language:English
Published: SpringerOpen 2022-09-01
Series:Journal of Inequalities and Applications
Subjects:
Online Access:https://doi.org/10.1186/s13660-022-02855-4
Description
Summary:Abstract We use a nontrivial concircular vector field u on the unit sphere S n + 1 $\mathbf{S}^{n+1}$ in studying geometry of its hypersurfaces. An orientable hypersurface M of the unit sphere S n + 1 $\mathbf{S}^{n+1}$ naturally inherits a vector field v and a smooth function ρ. We use the condition that the vector field v is an eigenvector of the de-Rham Laplace operator together with an inequality satisfied by the integral of the Ricci curvature in the direction of the vector field v to find a characterization of small spheres in the unit sphere S n + 1 $\mathbf{S}^{n+1}$ . We also use the condition that the function ρ is a nontrivial solution of the Fischer–Marsden equation together with an inequality satisfied by the integral of the Ricci curvature in the direction of the vector field v to find another characterization of small spheres in the unit sphere S n + 1 $\mathbf{S}^{n+1}$ .
ISSN:1029-242X