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The goal of this paper is to study weakly Einstein critical metrics of the volume functional on a compact manifold $M$ with smooth boundary $\partial M$. Here, we will give the complete classification for an $n$-dimensional, $n=3$ or $4,$…

微分几何 · 数学 2018-09-28 H. Baltazar , A. Da Silva , F. Oliveira

An $(\alpha,\beta)$-metric is defined by a Riemannian metric $\alpha$ and $1$-form $\beta$. In this paper, we study a known class of two-dimensional $(\alpha,\beta)$-metrics of vanishing S-curvature. We determine the local structure of…

微分几何 · 数学 2014-06-12 Guojun Yang

We classify weakly Einstein algebraic curvature tensors in an oriented Euclidean 4-space, defined by requiring that the three-index contraction of the curvature tensor against itself be a multiple of the inner product. This algebraic…

微分几何 · 数学 2026-02-02 Andrzej Derdzinski , JeongHyeong Park , Wooseok Shin

In this paper, a characteristic condition of Einstein Kropina metrics is given. By the characteristic condition, we prove that a non-Riemannian Kropina metric $F=\frac{\alpha^2}{\beta}$ with constant Killing form $\beta$ on an n-dimensional…

微分几何 · 数学 2012-07-10 Xiaoling Zhang , Yi-Bing Shen

First, we show that a warped product of a line and a fiber manifold is weakly conformally flat and quasi Einstein if and only if the fiber is Einstein. Next, we characterize and classify contact (in particular, $K$-contact) Riemannian…

微分几何 · 数学 2022-12-02 Ramesh Sharma

In this paper, we study the Randers metrics of weakly isotropic scalar curvature. We prove that a Randers metric of weakly isotropic scalar curvature must be of isotropic $S$-curvature. Further, we prove that a conformally flat Randers…

微分几何 · 数学 2020-06-19 Xinyue Cheng , Yannian Gong

The conformal properties of metrics are meaningful in Riemannian and Finsler geometry, and cubic metrics are useful in physics and biology. In this paper, we study the conformally flat cubic metrics with weakly isotropic scalar curvature.…

微分几何 · 数学 2023-09-04 Cuiling Ma , Xiaoling Zhang

A weakly Einstein manifold is a generalization of a 4-dimensional Einstein manifold, which is defined as an application of a curvature identity derived from the generalized Gauss-Bonnet formula for a 4-dimensional compact oriented…

微分几何 · 数学 2010-10-20 Y. Euh , J. H. Park , K. Sekigawa

A Riemannian manifold $(M,g)$ is called \emph{weakly Einstein} if the tensor $R_{iabc}R_{j}^{~~abc}$ is a scalar multiple of the metric tensor $g_{ij}$. We give a complete classification of weakly Einstein hypersurfaces in the spaces of…

微分几何 · 数学 2024-12-18 Jihun Kim , Yuri Nikolayevsky , JeongHyeong Park

An $(\alpha,\beta)$-metric is defined by a Riemannian metric and $1$-form. In this paper, we investigate the known characterization for $(\alpha,\beta)$-metrics of isotropic S-curvature. We show that such a characterization should hold in…

微分几何 · 数学 2014-06-12 Guojun Yang

In this paper, we study a class of Finsler metrics called general (\alpha,\beta)-metrics, which are defined by a Riemannian metric and an 1-form. We construct some general (\alpha,\beta)-metrics with constant Ricci curvature.

微分几何 · 数学 2013-07-02 Zhongmin Shen , Changtao Yu

Riemannian four-manifolds in which the triple contraction of the curvature tensor against itself yields a functional multiple of the metric are called weakly Einstein. We focus on weakly Einstein K\"ahler surfaces. We provide several…

微分几何 · 数学 2026-01-26 Andrzej Derdzinski , Yunhee Euh , Sinhwi Kim , JeongHyeong Park

In this paper, we introduce the notion of Einstein-reversibility for Finsler met- rics. We study a class of p-power Finsler metrics determined by a Riemann metric and 1-form which are of Einstein-reversibility. It shows that such a class of…

微分几何 · 数学 2013-10-17 Guojun Yang

One says that a Riemannian four-manifold is \emph{weakly Einstein} if the three-index contraction of its curvature tensor against itself equals a function times the metric. Since this includes all four-manifolds that are Einstein, or…

微分几何 · 数学 2025-12-08 Andrzej Derdzinski , JeongHyeong Park , Wooseok Shin

Let $M=G/K$ be a generalized flag manifold, that is the adjoint orbit of a compact semisimple Lie group $G$. We use the variational approach to find invariant Einstein metrics for all flag manifolds with two isotropy summands. We also…

微分几何 · 数学 2019-11-25 Andreas Arvanitoyeorgos , Ioannis Chrysikos

Various curvature conditions are studied on metrics admitting a symmetry group. We begin by examining a method of diagonalizing cohomogeneity-one Einstein manifolds and determine when this method can and cannot be used. Examples, including…

微分几何 · 数学 2007-05-23 Brandon Dammerman

In this paper, we study an important class of Finsler metrics--square metrics. We give two expressions of such metrics in terms of a Riemannian metric and a 1-form. We show that Einstein square metrics can be classified up to the…

微分几何 · 数学 2012-09-19 Zhongmin Shen , Changtao Yu

In this paper, we find a condition on $(\alpha, \beta)$-metrics under which the notions of isotropic S-curvature, weakly isotropic S-curvature and isotropic mean Berwald curvature are equivalent.

微分几何 · 数学 2014-12-25 Behzad Najafi , Akbar Tayebi

We describe space--time fluctuations by means of small fluctuations of the metric on a given background metric. From a minimally coupled Klein--Gordon equation we obtain within a weak-field approximation up to second order and an averaging…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Ertan Göklü , Claus Lämmerzahl

In this paper, we study weakly orthogonally invariant Finsler metrics and derive explicit expressions for their Berwald and Landsberg curvatures. We then obtain the system of partial differential equations characterizing generalized Finsler…

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