中文
相关论文

相关论文: Non-Berwaldian Randers metrics of Douglas type on …

200 篇论文

In the present paper we study Randers metics of Berwald type on simply connected 4-dimensional real Lie groups admitting invariant hypercomplex structure. On these spaces, the Randers metrics arising from invariant hyper-Hermitian metrics…

微分几何 · 数学 2016-12-30 H. R. Salimi Moghaddam

In the present paper, the flag curvature of invariant Randers metrics on homogeneous spaces and Lie groups is studied. We first give an explicit formula for the flag curvature of invariant Randers metrics arising from invariant Riemannian…

微分几何 · 数学 2016-12-30 H. R. Salimi Moghaddam

In this paper we identify all simply connected 3-dimensional real Lie groups which admit Randers or Matsumoto metrics of Berwald type with a certain underlying left invariant Riemannian metric. Then we give their flag curvatures formulas…

微分几何 · 数学 2016-05-10 Hamid Reza Salimi Moghaddam

In this short article, using a left-invariant Randers metric $F$, we define a new left-invariant Randers metric $\tilde{F}$. We show that $F$ is of Berwald (Douglas) type if and only if $\tilde{F}$ is of Berwald (Douglas) type. In the case…

微分几何 · 数学 2024-08-01 Azar Fatahi , Masoumeh Hosseini , Hamid Reza Salimi Moghaddam

In this paper, firstly we study some left invariant Riemannian metrics on para-hypercomplex 4-dimensional Lie groups. In each Lie group, the Levi-Civita connection and sectional curvature have been given explicitly. We also show these…

微分几何 · 数学 2015-07-09 H. R. Salimi Moghaddam

We give the explicit formulas of the flag curvatures of left invariant Matsumoto and Kropina metrics of Berwald type. We can see these formulas are different from previous results given recently. Using these formulas, we prove that at any…

微分几何 · 数学 2024-07-23 Masoumeh Hosseini , Hamid Reza Salimi Moghaddam

Let $G$ be a Lie group equipped with a left invariant Randers metric of Berward type $F$, with underlying left invariant Riemannian metric $g$. Suppose that $\widetilde{F}$ and $\widetilde{g}$ are lifted Randers and Riemannian metrics…

微分几何 · 数学 2018-08-08 Farhad Asgari , Hamid Reza Salimi Moghaddam

In this paper we study the geometry of simply connected two-step nilpotent Lie groups of dimension five. We give the Levi-Civita connection, curvature tensor, sectional and scalar curvatures of these spaces and show that they have constant…

微分几何 · 数学 2016-12-30 H. R. Salimi Moghaddam

In this paper we classify all simply connected five dimensional nilpotent Lie groups which admit $(\alpha,\beta)$-metrics of Berwald and Douglas type defined by a left invariant Riemannian metric and a left invariant vector field. During…

微分几何 · 数学 2024-07-23 Masoumeh Hosseini , Hamid Reza Salimi Moghaddam

In this paper we study lifted left invariant $(\alpha,\beta)$-metrics of Douglas type on tangent Lie groups. Let $G$ be a Lie group equipped with a left invariant $(\alpha,\beta)$-metric of Douglas type $F$, induced by a left invariant…

微分几何 · 数学 2024-07-23 Masumeh Nejadahmad , Hamid Reza Salimi Moghaddam

In this article we review the recent results about the flag curvature of invariant Randers metrics on homogeneous manifolds and by using a counter example we show that the formula which obtained for the flag curvature of these metrics is…

微分几何 · 数学 2016-12-30 E. Esrafilian , H. R. Salimi Moghaddam

In this paper we study sectional curvature of invariant hyper-Hermitian metrics on simply connected 4-dimensional real Lie groups admitting invariant hypercomplex structure. We give the Levi-Civita connections and explicit formulas for…

微分几何 · 数学 2016-12-30 H. R. Salimi Moghaddam

In this paper by using left invariant Riemannian metrics on some 3-dimensional Lie groups we construct some complete non-Riemannian Berwald spaces of non-positive flag curvature and several families of geodesically complete locally…

微分几何 · 数学 2016-12-30 H. R. Salimi Moghaddam

In this paper, we classify the spherically symmetric Berwald metrics in $\mathbb{R}^n$. For the spherically symmetric Landsberg metrics, we prove that there do not exist any non-Berwald metrics among the regular case. The partial…

微分几何 · 数学 2014-10-31 Xiaohuan Mo , Linfeng Zhou

A left invariant Z-Randers metric on the five-dimensional Heisenberg group is a left invariant Randers metric with deformation vector from the center of the Heisenberg algebra. In this note we prove that for every left invariant Z-Randers…

微分几何 · 数学 2016-04-12 A. Lengyelné-Tóth , Z. Kovács

We begin by studying the Riemannian geometry of the tangent Lie group $TG$ associated with a Lie group $G$ whose commutator subgroup is two-dimensional, equipped with the lift of a left-invariant Riemannian metric on $G$. We establish the…

微分几何 · 数学 2026-04-30 Ali Hatami Shahi , Hamid Reza Salimi Moghaddam

In this paper, we study a class of Finsler metrics which contains the class of Berwald metrics as a special case. We prove that every Finsler metric in this class is a generalized Douglas-Weyl metric. Then we study isotropic flag curvature…

微分几何 · 数学 2010-01-21 Akbar Tayebi , Esmaeil Peyghan

We show that two-dimensional conformally related Douglas metrics are Randers

微分几何 · 数学 2021-06-08 Vladimir S. Matveev , Samaneh Saberali

In this paper, we prove two rigidity results for non-positively curved homogeneous Finsler metrics. Our first main result yields an extension of Hu-Deng's well-known result proven for the Randers metrics. Indeed, we prove that every…

微分几何 · 数学 2021-04-07 B. Najafi , A. Tayebi

In this paper, we investigate the spherically symmetric Finsler metrics with isotropic S-curvature and obtain a characterized equation. As an application, we prove that these metrics with Douglas type must be Randers metrics or Berwald…

微分几何 · 数学 2014-10-31 Linfeng Zhou
‹ 上一页 1 2 3 10 下一页 ›