• Title/Summary/Keyword: 4-manifolds

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SASAKIAN STRUCTURES ON PRODUCTS OF REAL LINE AND KÄHLERIAN MANIFOLD

  • Beldjilali, Gherici;Cherif, Ahmed Mohammed;Zaga, Kaddour
    • Korean Journal of Mathematics
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    • v.27 no.4
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    • pp.1061-1075
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    • 2019
  • In this paper, we construct a Sasakian manifold by the product of real line and Kählerian manifold with exact Kähler form. This result demonstrates the close relation between Sasakian and Kählerian manifold with exact Kähler form. We present an example and an open problem.

On Some Properties of Riemannian Manifolds with a Generalized Connection

  • Dehkordy, Azam Etemad
    • Kyungpook Mathematical Journal
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    • v.56 no.4
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    • pp.1237-1246
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    • 2016
  • In this paper we study some properties of submanifolds of a Riemannian manifold equipped with a generalized connection $\hat{\nabla}$. We also consider almost Hermitian manifolds that admits a special case of this generalized connection and derive some results about the behavior of this manifolds.

On N(κ)-Contact Metric Manifolds Satisfying Certain Curvature Conditions

  • De, Avik;Jun, Jae-Bok
    • Kyungpook Mathematical Journal
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    • v.51 no.4
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    • pp.457-468
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    • 2011
  • We consider pseudo-symmetric and Ricci generalized pseudo-symmetric N(${\kappa}$) contact metric manifolds. We also consider N(${\kappa}$)-contact metric manifolds satisfying the condition $S{\cdot}R$ = 0 where R and S denote the curvature tensor and the Ricci tensor respectively. Finally we give some examples.

INVARIANT SUBMANIFOLDS OF (LCS)n-MANIFOLDS ADMITTING CERTAIN CONDITIONS

  • Eyasmin, Sabina;Baishya, Kanak Kanti
    • Honam Mathematical Journal
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    • v.42 no.4
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    • pp.829-841
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    • 2020
  • The object of the present paper is to study the invariant submanifolds of (LCS)n-manifolds. We study generalized quasi-conformally semi-parallel and 2-semiparallel invariant submanifolds of (LCS)n-manifolds and showed their existence by a non-trivial example. Among other it is shown that an invariant submanifold of a (LCS)n-manifold is totally geodesic if the second fundamental form is any one of (i) symmetric, (ii) recurrent, (iii) pseudo symmetric, (iv) almost pseudo symmetric and (v) weakly pseudo symmetric.

𝜂-Einstein Solitons on (𝜀)-Kenmotsu Manifolds

  • Siddiqi, Mohd Danish;Chaubey, Sudhakar Kumar
    • Kyungpook Mathematical Journal
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    • v.60 no.4
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    • pp.805-819
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    • 2020
  • The objective of this study is to investigate 𝜂-Einstein solitons on (𝜀)-Kenmotsu manifolds when the Weyl-conformal curvature tensor satisfies some geometric properties such as being flat, semi-symmetric and Einstein semi-symmetric. Here, we discuss the properties of 𝜂-Einstein solitons on 𝜑-symmetric (𝜀)-Kenmotsu manifolds.

QUASI-CONFORMAL CURVATURE TENSOR ON N (k)-QUASI EINSTEIN MANIFOLDS

  • Hazra, Dipankar;Sarkar, Avijit
    • Korean Journal of Mathematics
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    • v.29 no.4
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    • pp.801-810
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    • 2021
  • This paper deals with the study of N (k)-quasi Einstein manifolds that satisfies the certain curvature conditions 𝒞*·𝒞* = 0, 𝓢·𝒞* = 0 and ${\mathcal{R}}{\cdot}{\mathcal{C}}_*=f{\tilde{Q}}(g,\;{\mathcal{C}}_*)$, where 𝒞*, 𝓢 and 𝓡 denotes the quasi-conformal curvature tensor, Ricci tensor and the curvature tensor respectively. Finally, we construct an example of N (k)-quasi Einstein manifold.

GENERALIZED 𝜂-RICCI SOLITONS ON QUASI-SASAKIAN 3-MANIFOLDS ASSOCIATED TO THE SCHOUTEN-VAN KAMPEN CONNECTION

  • Shahroud Azami
    • Honam Mathematical Journal
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    • v.45 no.4
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    • pp.655-667
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    • 2023
  • In this paper, we study quasi-Sasakian 3-dimensional manifolds admitting generalized 𝜂-Ricci solitons associated to the Schouten-van Kampen connection. We give an example of generalized 𝜂-Ricci solitons on a quasi-Sasakian 3-dimensional manifold with respect to the Schouten-van Kampen connection to prove our results.