中文
相关论文

相关论文: Curvatures of Stiefel manifolds with deformation m…

200 篇论文

We consider the problem of finding complete conformal metrics with prescribed curvature functions of the Einstein tensor and of more general modified Schouten tensors. To achieve this, we reveal an algebraic structure of a wide class of…

微分几何 · 数学 2021-05-04 Rirong Yuan

Various tasks in scientific computing can be modeled as an optimization problem on the indefinite Stiefel manifold. We address this using the Riemannian approach, which basically consists of equipping the feasible set with a Riemannian…

最优化与控制 · 数学 2026-04-17 Dinh Van Tiep , Duong Thi Viet An , Nguyen Thi Ngoc Oanh , Nguyen Thanh Son

Methods and algorithms that work with data on nonlinear manifolds are collectively summarized under the term `Riemannian computing'. In practice, curvature can be a key limiting factor for the performance of Riemannian computing methods.…

数值分析 · 数学 2024-04-22 Ralf Zimmermann , Jakob Stoye

We first provide an alternative proof of the classical Weitzneb\"ock formula for Einstein four-manifolds using Berger curvature decomposition, motivated by which we establish a unified framework for a Weitzenb\"ock formula for a large class…

微分几何 · 数学 2014-11-13 Peng Wu

This paper is devoted to the first systematic investigation of manifolds that are Einstein for a connection with skew symmetric torsion. We derive the Einstein equation from a variational principle and prove that, for parallel torsion, any…

微分几何 · 数学 2022-10-07 Ilka Agricola , Ana Cristina Ferreira

Consider a compact manifold $M$ with smooth boundary $\partial M$. Suppose that $g$ and $\tilde{g}$ are two Riemannian metrics on $M$. We construct a family of metrics on $M$ which agrees with $g$ outside a neighborhood of $\partial M$ and…

微分几何 · 数学 2021-03-12 Tsz-Kiu Aaron Chow

We consider the curvature of a family of warped products of two pseduo-Riemannian manifolds $(B,g_B)$ and $(F,g_F)$ furnished with metrics of the form $c^{2}g_B \oplus w^2 g_F$ and, in particular, of the type $w^{2 \mu}g_B \oplus w^2 g_F$,…

微分几何 · 数学 2008-11-26 Fernando Dobarro , Bulent Unal

We present three families of exact, cohomogeneity-one Einstein metrics in $(2n+2)$ dimensions, which are generalizations of the Stenzel construction of Ricci-flat metrics to those with a positive cosmological constant. The first family of…

高能物理 - 理论 · 物理学 2019-04-26 M. Cvetic , G. W. Gibbons , C. N. Pope

Using recent work of Bettiol, we show that a first-order conformal deformation of Wilking's metric of almost-positive sectional curvature on $S^2\times S^3$ yields a family of metrics with strictly positive average of sectional curvatures…

微分几何 · 数学 2020-07-20 Boris Stupovski , Rafael Torres

This paper investigates conformal deformations of the scalar curvature and mean curvature on complete Riemannian manifolds with boundary. We establish sufficient conditions for the existence of conformal deformations to complete metrics…

微分几何 · 数学 2025-01-22 Tiarlos Cruz , Almir Silva Santos

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

Several Riemannian metrics and families of Riemannian metrics were defined on the manifold of Symmetric Positive Definite (SPD) matrices. Firstly, we formalize a common general process to define families of metrics: the principle of…

微分几何 · 数学 2021-11-05 Yann Thanwerdas , Xavier Pennec

In this paper, we investigate the geometry of the base complex manifold of an effectively parametrized holomorphic family of stable Higgs bundles over a fixed compact K\"{a}hler manifold. The starting point of our study is…

微分几何 · 数学 2021-07-28 Zhi Hu , Pengfei Huang

All spherically symmetric Riemannian metrics of constant scalar curvature in any dimension can be written down in a simple form using areal coordinates. All spherical metrics are conformally flat, so we search for the conformally flat…

广义相对论与量子宇宙学 · 物理学 2015-06-19 Patryk Mach , Niall Ó Murchadha

In this paper, we study closed four-dimensional manifolds. In particular, we show that under various new pinching curvature conditions (for example, the sectional curvature is no more than 5/6 of the smallest Ricci eigenvalue) then the…

微分几何 · 数学 2022-08-31 Xiaodong Cao , Hung Tran

In this article, we first show that for all compact Riemannian manifolds with non-empty smooth boundary and dimension at least 3, there exists a metric, pointwise conformal to the original metric, with constant scalar curvature in the…

微分几何 · 数学 2022-08-25 Jie Xu

Seiberg-Witten theory leads to a delicate interplay between Riemannian geometry and smooth topology in dimension four. In particular, the scalar curvature of any metric must satisfy certain non-trivial estimates if the manifold in question…

微分几何 · 数学 2016-09-07 Claude LeBrun

This paper mainly contributes to a classification of statistical Einstein manifolds, namely statistical manifolds at the same time are Einstein manifolds. A statistical manifold is a Riemannian manifold, each of whose points is a…

数学物理 · 物理学 2019-08-30 Linyu Peng , Zhenning Zhang

We study the geometry of the tangent bundle equipped with a two-parameter family of Riemannian metrics. After deriving the expression of the Levi-Civita connection, we compute the Riemann curvature tensor and the sectional, Ricci and scalar…

微分几何 · 数学 2009-02-06 M. Benyounes , E. Loubeau , C. M. Wood

Given an Einstein structure with positive scalar curvature on a four-dimensional Riemannian manifolds, that is $Ric=\lambda g$ for some positive constant $\lambda$. For convenience, the Ricci curvature is always normalized to $Ric=1$. A…

微分几何 · 数学 2016-06-06 Zhuhong Zhang
‹ 上一页 1 2 3 10 下一页 ›