English
Related papers

Related papers: Positively curved homogeneous metrics on spheres

200 papers

We introduce a compactification of the space of simple positive divisors on a Riemann surface, as well as a compactification of the universal family of punctured surfaces above this space. These are real manifolds with corners. We then…

Differential Geometry · Mathematics 2020-09-02 Rafe Mazzeo , Xuwen Zhu

We prove that closed manifolds admitting a generic metric whose sectional curvature is locally quasi-constant are graphs of space forms. In the more general setting of QC spaces where sets of isotropic points are arbitrary, under suitable…

Differential Geometry · Mathematics 2020-04-08 Louis Funar

As a means to better understanding manifolds with positive curvature, there has been much recent interest in the study of non-negatively curved manifolds which contain points at which all 2-planes have positive curvature. We show that there…

Differential Geometry · Mathematics 2014-11-11 Martin Kerin

In this article we give a criterion for the existence of a metric of curvature $1$ on a $2$-sphere with $n$ conical singularities of prescribed angles $2\pi\vartheta_1,\dots,2\pi\vartheta_n$ and non-coaxial holonomy. Such a necessary and…

Differential Geometry · Mathematics 2016-02-01 Gabriele Mondello , Dmitri Panov

We determine the homeomorphism type of the space of smooth complete nonnegatively curved metrics on surfaces of positive Euler characteristic equipped with the topology of $C^\gamma$ uniform convergence on compact sets, when $\gamma$ is…

Differential Geometry · Mathematics 2017-03-03 Taras Banakh , Igor Belegradek

A Finsler space $(M,F)$ is called flag-wise positively curved, if for any $x\in M$ and any tangent plane $\mathbf{P}\subset T_xM$, we can find a nonzero vector $y\in \mathbf{P}$, such that the flag curvature $K^F(x,y, \mathbf{P})>0$. Though…

Differential Geometry · Mathematics 2016-06-09 Ming Xu

We classify the complete metrics of nonnegative sectional curvature on M^2xR^2, where M^2 is any compact 2-manifold.

Differential Geometry · Mathematics 2007-05-23 Detlef Gromoll , Kristopher Tapp

On one hand, we study the class of graphs on surfaces, satisfying tessellation properties, with positive Forman curvature on each edge. Via medial graphs, we provide a new proof for the finiteness of the class, and give a complete…

Combinatorics · Mathematics 2020-02-11 Yohji Akama , Bobo Hua , Yanhui Su , Haohang Zhang

We show that any closed biquotient with finite fundamental group admits metrics of positive Ricci curvature. Also, let M be a closed manifold on which a compact Lie group G acts with cohomogeneity one, and let L be a closed subgroup of G…

Differential Geometry · Mathematics 2007-05-23 Lorenz Schwachhoefer , Wilderich Tuschmann

We show that results about spaces or moduli spaces of positive scalar curvature metrics proved using index theory can typically be extended to non-negative scalar curvature metrics. We illustrate this by providing explicit generalizations…

Differential Geometry · Mathematics 2021-01-12 Thomas Schick , David J. Wraith

In this paper we give a classification of cohomogeneity one manifolds admitting an invariant metric with quasipositive sectional curvature except for two $7$-dimensional families. The main result carries over almost verbatim from the…

Differential Geometry · Mathematics 2022-10-17 Dennis Wulle

We establish the existence of complete K\"ahler metrics of semi-positive holomorphic sectional curvature with many zeroes in an interesting and natural geometric setting. Specifically, we use Calabi's Ansatz in the form due to Koiso-Sakane…

Differential Geometry · Mathematics 2023-08-25 Minzi Chen , Gordon Heier

In this paper we study spaces of Riemannian metrics with lower bounds on intermediate curvatures. We show that the spaces of metrics of positive p-curvature and k-positive Ricci curvature on a given high-dimensional Spin-manifold have many…

Differential Geometry · Mathematics 2022-01-28 Georg Frenck , Jan-Bernhard Kordaß

In this paper we use the relationship between conformal metrics on the sphere and horospherically convex hypersurfaces in the hyperbolic space for giving sufficient conditions on a conformal metric to be radial under some constrain on the…

Differential Geometry · Mathematics 2008-11-17 Jose M. Espinar

We classify complete curvature homogeneous metrics on simply connected four dimensional manifolds which are invariant under a cohomogeneity one action. We show that they are either isometric to a symmetric space with one of its…

Differential Geometry · Mathematics 2020-10-20 Luigi Verdiani , Wolfgang Ziller

We consider invariant Riemannian metrics on compact homogeneous spaces $G/H$ where an intermediate subgroup $K$ between $G$ and $H$ exists. In this case, the homogeneous space $G/H$ is the total space of a Riemannian submersion. The metrics…

Differential Geometry · Mathematics 2012-11-13 Megan M. Kerr , Andreas Kollross

In this paper, studying the inverse problem, we establish a curvature compatibility condition on a spherically symmetric Finsler metric. As an application, we characterize the spherically symmetric metrics of scalar curvature. We construct…

Differential Geometry · Mathematics 2024-07-08 S. G. Elgendi

We construct metrics of positive Ricci curvature on some vector bundles over tori (or more generally, over nilmanifolds). This gives rise to the first examples of manifolds with positive Ricci curvature which are homotopy equivalent but not…

Differential Geometry · Mathematics 2007-05-23 Igor Belegradek , Guofang Wei

Let $M$ be a simply connected spin manifold of dimension at least six which admits a metric of positive scalar curvature. We show that the observer moduli space of positive scalar curvature metrics on $M$ has non-trivial higher homotopy…

Geometric Topology · Mathematics 2021-07-26 Michael Wiemeler

We prove the scalar curvature rigidity for $L^\infty$ metrics on $\mathbb S^n\backslash\Sigma$, where $\mathbb S^n$ is the $n$-dimensional sphere with $n\geq 3$ and $\Sigma$ is a closed subset of $\mathbb S^n$ of codimension at least…

Differential Geometry · Mathematics 2026-05-21 Jinmin Wang , Zhizhang Xie