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We construct all Finsler metrics on the two-sphere for which geodesics are circles and show that any (reversible) path geometry on a two-dimensional manifold is locally the system of geodesics of a Finsler metric.

Differential Geometry · Mathematics 2010-02-02 Juan-Carlos Álvarez-Paiva , Gautier Berck

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

We show that an enlargeable Riemannian metric on a (possibly nonspin) manifold cannot have uniformly positive scalar curvature. This extends a well-known result of Gromov and Lawson to the nonspin setting. We also prove that every…

Geometric Topology · Mathematics 2021-01-01 Simone Cecchini , Thomas Schick

We extend two celebrated theorems on closed geodesics of Riemannian 2-spheres to the larger class of reversible Finsler 2-spheres: Lusternik-Schnirelmann's theorem asserting the existence of three simple closed geodesics, and…

Differential Geometry · Mathematics 2022-04-11 Guido De Philippis , Michele Marini , Marco Mazzucchelli , Stefan Suhr

We show that the shortest closed geodesic on a 2-sphere with non-negative curvature has length bounded above by three times the diameter. We prove a new isoperimetric inequality for 2-spheres with pinched curvature; this allows us to…

Differential Geometry · Mathematics 2021-09-08 Ian Adelstein , Franco Vargas Pallete

We establish a one-to-one correspondence between Finsler structures on the $2$-sphere with constant curvature $1$ and all geodesics closed on the one hand, and Weyl connections on certain spindle orbifolds whose symmetric Ricci curvature is…

Differential Geometry · Mathematics 2024-10-22 Christian Lange , Thomas Mettler

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…

Differential Geometry · Mathematics 2021-04-07 B. Najafi , A. Tayebi

A Riemannian or Finsler metric on a compact manifold M gives rise to a length function on the free loop space \Lambda M, whose critical points are the closed geodesics in the given metric. If X is a homology class on \Lambda M, the minimax…

Differential Geometry · Mathematics 2012-05-14 Nancy Hingston , Hans-Bert Rademacher

We construct a concrete example of constant Gauss curvature $K = 1$ on the 2-sphere having all geodesics closed and of same length.

Differential Geometry · Mathematics 2021-02-02 I. Masca , S. V. Sabau , H. Shimada

For a Riemannian metric $g$ on the two-sphere, let $\ell_{\min}(g)$ be the length of the shortest closed geodesic and $\ell_{\max}(g)$ be the length of the longest simple closed geodesic. We prove that if the curvature of $g$ is positive…

Differential Geometry · Mathematics 2019-12-10 Alberto Abbondandolo , Barney Bramham , Umberto L. Hryniewicz , Pedro A. S. Salomão

We establish sharp universal upper bounds on the length of the shortest closed geodesic on a punctured sphere with three or four ends endowed with a complete Riemannian metric of finite area. These sharp curvature-free upper bounds are…

Differential Geometry · Mathematics 2020-09-23 Antonia Jabbour , Stéphane Sabourau

We show that every forward complete Finsler manifold of infinite fundamental group and not homotopy-equivalent to $S^1$ has infinitely many geometrically distinct geodesics joining any given pair of points $p$ and $q$. In the special case…

Differential Geometry · Mathematics 2022-01-21 Simon Allais

We study the following problem: given an Einstein metric on a manifold, characterize and study all Einstein metrics which are pointwise projective to the given one. By definition, two metrics are said to be pointwise projectively related if…

Metric Geometry · Mathematics 2007-05-23 Zhongmin Shen

Let $(M, \partial M)$ be a compact 3-manifold with boundary, which admits a convex co-compact hyperbolic metric. We consider the hyperbolic metrics on $M$ such that the boundary is smooth and strictly convex. We show that the induced…

Differential Geometry · Mathematics 2015-06-26 Jean-Marc Schlenker

We give a Morse-theoretic characterization of simple closed geodesics on Riemannian $2$-spheres. On any Riemannian $2$-sphere endowed with a generic metric, we show there exists a simple closed geodesic with Morse index $1$, $2$ and $3$. In…

Differential Geometry · Mathematics 2023-04-13 Dongyeong Ko

Cone spherical metrics are conformal metrics with constant curvature one and finitely many conical singularities on compact Riemann surfaces. A cone spherical metric is called irreducible if each developing map of the metric does not have…

Algebraic Geometry · Mathematics 2022-10-11 Lingguang Li , Jijian Song , Bin Xu

In this paper, we discuss how to travel along horizontal broken geodesics of a homogenous Finsler submersion, i.e., we study, what in Riemannian geometry was called by Wilking, the dual leaves. More precisely, we investigate the attainable…

Differential Geometry · Mathematics 2022-04-29 Marcos M. Alexandrino , Fernando M. Escobosa , Marcelo K. Inagaki

We show that there exists a metric with positive scalar curvature on S2xS1 and a sequence of embedded minimal cylinders that converges to a minimal lamination that, in a neighborhood of a strictly stable 2-sphere, is smooth except at two…

Differential Geometry · Mathematics 2008-03-06 Maria Calle , Darren Lee

In this paper, we obtain a necessary and sufficient condition for a $U(n)$-invariant complex Finsler metric $F$ on domains in $\mathbb{C}^n$ to be strongly convex, which also makes it possible to investigate relationship between real and…

Differential Geometry · Mathematics 2020-05-21 Kun Wang , Hongchuan Xia , Chunping Zhong

We give a proof of an unpublished result of Thurston showing that given any hyperbolic metric on a surface of finite type with nonempty boundary, there exists another hyperbolic metric on the same surface for which the lengths of all simple…

Geometric Topology · Mathematics 2009-09-09 Athanase Papadopoulos , Guillaume Théret