• Communications of the Korean Mathematical Society
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• v.36 no.1
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• pp.135-147
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• 2021

In this paper, we introduce the harmonicity of a covector field on a Riemannian manifold (M, g) to its cotangent bundle T∗ M equipped with g-natural metric. Afterward we also construct some examples of harmonic covector fields.

• Communications of the Korean Mathematical Society
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• v.36 no.3
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• pp.575-592
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• 2021

In this paper, we introduce the Berger type deformed Sasaki metric on the cotangent bundle T^*M over an anti-paraKähler manifold (M, 𝜑, g) as a new natural metric with respect to g non-rigid on T^*M. Firstly, we investigate the Levi-Civita connection of this metric. Secondly, we study the curvature tensor and also we characterize the scalar curvature.

• The Pure and Applied Mathematics
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• v.19 no.3
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• pp.239-249
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• 2012

For each submanifold X in the sphere $S^n$; we show that the corresponding conormal bundle $N^*X$ is Lagrangian for the Stenzel form on $T^*S^n$. Furthermore, we correspond an austere submanifold X to a special Lagrangian submanifold $N^*X$ in $T^*S^n$. We also discuss austere submanifolds in $S^n$ from isoparametric geometry.