{"title":"几乎Kenmotsu流形承认某些向量场","authors":"D. Dey, P. Majhi","doi":"10.22034/KJM.2020.235131.1873","DOIUrl":null,"url":null,"abstract":"In the present paper, we characterize almost Kenmotsu manifolds admitting holomorphically planar conformal vector (HPCV) fields. We have shown that if an almost Kenmotsu manifold $M^{2n+1}$ admits a non-zero HPCV field $V$ such that $\\phi V = 0$, then $M^{2n+1}$ is locally a warped product of an almost Kaehler manifold and an open interval. As a corollary of this we obtain few classifications of an almost Kenmotsu manifold to be a Kenmotsu manifold and also prove that the integral manifolds of D are totally umbilical submanifolds of $M^{2n+1}$. Further, we prove that if an almost Kenmotsu manifold with positive constant $\\xi$-sectional curvature admits a non-zero HPCV field $V$, then either $M^{2n+1}$ is locally a warped product of an almost Kaehler manifold and an open interval or isometric to a sphere. Moreover, a $(k,\\mu)'$-almost Kenmotsu manifold admitting a HPCV field $V$ such that $\\phi V = 0$ is either locally isometric to $\\mathbb{H}^{n+1}(-4) \\times \\mathbb{R}^n$ or $V$ is an eigenvector of $h'$. Finally, an example is presented.","PeriodicalId":8430,"journal":{"name":"arXiv: Differential Geometry","volume":"69 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Almost Kenmotsu manifolds admitting certain vector fields\",\"authors\":\"D. Dey, P. Majhi\",\"doi\":\"10.22034/KJM.2020.235131.1873\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"In the present paper, we characterize almost Kenmotsu manifolds admitting holomorphically planar conformal vector (HPCV) fields. We have shown that if an almost Kenmotsu manifold $M^{2n+1}$ admits a non-zero HPCV field $V$ such that $\\\\phi V = 0$, then $M^{2n+1}$ is locally a warped product of an almost Kaehler manifold and an open interval. As a corollary of this we obtain few classifications of an almost Kenmotsu manifold to be a Kenmotsu manifold and also prove that the integral manifolds of D are totally umbilical submanifolds of $M^{2n+1}$. Further, we prove that if an almost Kenmotsu manifold with positive constant $\\\\xi$-sectional curvature admits a non-zero HPCV field $V$, then either $M^{2n+1}$ is locally a warped product of an almost Kaehler manifold and an open interval or isometric to a sphere. Moreover, a $(k,\\\\mu)'$-almost Kenmotsu manifold admitting a HPCV field $V$ such that $\\\\phi V = 0$ is either locally isometric to $\\\\mathbb{H}^{n+1}(-4) \\\\times \\\\mathbb{R}^n$ or $V$ is an eigenvector of $h'$. Finally, an example is presented.\",\"PeriodicalId\":8430,\"journal\":{\"name\":\"arXiv: Differential Geometry\",\"volume\":\"69 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2020-04-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv: Differential Geometry\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.22034/KJM.2020.235131.1873\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv: Differential Geometry","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.22034/KJM.2020.235131.1873","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
在本文中,我们刻画了具有全纯平面共形矢量场的几乎Kenmotsu流形。我们证明了如果一个几乎Kenmotsu流形$M^{2n+1}$允许一个非零HPCV场$V$使得$\phi V = 0$,那么$M^{2n+1}$是一个几乎Kaehler流形与开区间的局部翘曲积。作为这一结论的推论,我们得到了几乎Kenmotsu流形为Kenmotsu流形的几个分类,并证明了D的积分流形是$M^{2n+1}$的完全脐带子流形。进一步证明了如果一个具有正常数$\xi$ -截面曲率的几乎Kenmotsu流形存在一个非零HPCV场$V$,那么$M^{2n+1}$要么是一个几乎Kaehler流形与球面的开区间或等距的局部翘曲积。此外,承认HPCV场$V$的$(k,\mu)'$ -几乎Kenmotsu流形使得$\phi V = 0$与$\mathbb{H}^{n+1}(-4) \times \mathbb{R}^n$局部等距或$V$是$h'$的特征向量。最后给出了一个实例。
Almost Kenmotsu manifolds admitting certain vector fields
In the present paper, we characterize almost Kenmotsu manifolds admitting holomorphically planar conformal vector (HPCV) fields. We have shown that if an almost Kenmotsu manifold $M^{2n+1}$ admits a non-zero HPCV field $V$ such that $\phi V = 0$, then $M^{2n+1}$ is locally a warped product of an almost Kaehler manifold and an open interval. As a corollary of this we obtain few classifications of an almost Kenmotsu manifold to be a Kenmotsu manifold and also prove that the integral manifolds of D are totally umbilical submanifolds of $M^{2n+1}$. Further, we prove that if an almost Kenmotsu manifold with positive constant $\xi$-sectional curvature admits a non-zero HPCV field $V$, then either $M^{2n+1}$ is locally a warped product of an almost Kaehler manifold and an open interval or isometric to a sphere. Moreover, a $(k,\mu)'$-almost Kenmotsu manifold admitting a HPCV field $V$ such that $\phi V = 0$ is either locally isometric to $\mathbb{H}^{n+1}(-4) \times \mathbb{R}^n$ or $V$ is an eigenvector of $h'$. Finally, an example is presented.