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Related papers: Summary of progress on the Blaschke conjecture

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We prove that on a compact Sasakian manifold $(M, \eta, g)$ of dimension $2n+1$, for any $0 \le p \le n$ the wedge product with $\eta \wedge (d\eta)^p$ defines an isomorphism between the spaces of harmonic forms $\Omega^{n-p}_\Delta (M)$…

Differential Geometry · Mathematics 2015-06-16 Beniamino Cappelletti Montano , Antonio De Nicola , Ivan Yudin

We consider smooth maps on compact Riemannian manifolds. We prove that under some mild condition of eventual volume expansion Lebesgue almost everywhere we have uniform backward volume contraction on every pre-orbit for Lebesgue almost…

Dynamical Systems · Mathematics 2007-05-23 Jose F. Alves , Armando Castro , Vilton Pinheiro

This paper explores the cohomological consequences of the existence of moduli spaces for flat bundles with bounded rank and irregularity at infinity and gives unconditional proofs. Namely, we prove the existence of a universal bound for the…

Algebraic Geometry · Mathematics 2025-02-26 Haoyu Hu , Jean-Baptiste Teyssier

Various theorems on convergence of general space homeomorphisms are proved and, on this basis, theorems on convergence and compactness for classes of the so-called ring $Q$--homeomorphisms are obtained. In particular, it was established by…

Complex Variables · Mathematics 2012-08-21 Vladimir Ryazanov , Evgeny Sevost'yanov

As is known, the Blaschke tensor $A$ (a symmetric covariant $2$-tensor) is one of the fundamental M\"obius invariants in the M\"obius differential geometry of submanifolds in the unit sphere $\mathbb S^n$, and the eigenvalues of $A$ are…

Differential Geometry · Mathematics 2015-12-04 Xingxiao Li , Hongru Song

Brinkmann Lorentz manifolds are those admitting an isotropic parallel vector field. We prove geodesic completeness of the compact and also compactly homogeneous Brinkmann spaces. We also prove, partially, that their parallel vector field…

Differential Geometry · Mathematics 2025-03-25 Lilia Mehidi , Abdelghani Zeghib

From a sufficiently large point sample lying on a compact Riemannian submanifold of Euclidean space, one can construct a simplicial complex which is homotopy-equivalent to that manifold with high confidence. We describe a corresponding…

Algebraic Topology · Mathematics 2013-10-15 Steve Ferry , Konstantin Mischaikow , Vidit Nanda

In this note we present a complete proof of the fact that all the submanifolds of a one parameter family of compact symplectic submanifolds inside a compact symplectic manifold are Hamiltonian isotopic.

Symplectic Geometry · Mathematics 2023-07-14 Paolo Antonini , Fabio Cavalletti , Antonio Lerario

We consider smooth maps on compact Riemannian manifolds. We prove that under some mild condition of eventual volume expansion Lebesgue almost everywhere we have uniform backward volume contraction on every pre-orbit of Lebesgue almost every…

Dynamical Systems · Mathematics 2009-10-22 Vilton Pinheiro , Armando Castro , J. F. Alves

We find a compactification of the $\mathrm{SL}(3,\mathbb{R})$-Hitchin component by studying the degeneration of the Blaschke metrics on the associated equivariant affine spheres. In the process, we establish the closure in the space of…

Differential Geometry · Mathematics 2021-06-04 Charles Ouyang , Andrea Tamburelli

We show that for every closed Riemannian manifold there exists a continuous family of $1$-cycles (defined as finite collections of disjoint closed curves) parametrized by a sphere and sweeping out the whole manifold so that the lengths of…

Differential Geometry · Mathematics 2020-07-30 Alexander Nabutovsky , Regina Rotman , Stéphane Sabourau

Gromov and Sormani conjectured that sequences of compact Riemannian manifolds with nonnegative scalar curvature and area of minimal surfaces bounded below should have subsequences which converge in the intrinsic flat sense to limit spaces…

Differential Geometry · Mathematics 2018-12-11 Jiewon Park , Wenchuan Tian , Changliang Wang

We show that a complete $3$-dimensional Riemannian manifold $M$ with finitely generated first homology has macroscopic dimension $1$ if it satisfies the following "macroscopic curvature" assumptions: every ball of radius $10$ in $M$ has…

Differential Geometry · Mathematics 2023-10-18 Hannah Alpert , Alexey Balitskiy , Larry Guth

In this paper, we build up a scaled homology theory, $lc$-homology, for metric spaces such that every metric space can be visually regarded as "locally contractible" with this newly-built homology. We check that $lc$-homology satisfies all…

Algebraic Topology · Mathematics 2023-06-07 Bingzhe Hou , Kiyoshi Igusa , Zihao Liu

A relatively simple algebraic framework is given, in which all the compact symmetric spaces can be described and handled without distinguishing cases. We also give some applications and further results.

Differential Geometry · Mathematics 2008-04-09 Adam Korányi , Fulvio Ricci

In this paper, we address several interconnected problems in the theory of harmonic maps between Riemannian manifolds. First, we present necessary background and establish one of the main results of the paper: a criterion characterizing…

Differential Geometry · Mathematics 2025-07-14 Sergey Stepanov , Irina Tsyganok

For $C^0$ generic continuous maps or homeomorphisms on compact Riemannian manifold, we prove that (1) the space of physical-like measures coincides with the set of invariant measures supported on chain recurrent classes, (2) every point in…

Dynamical Systems · Mathematics 2019-07-23 Xueting Tian

We provide a short proof for the theorem that two compact Riemannian manifolds are isomorphic if and only there exists an order isomorphism which intertwines between the heat semigroups on the manifolds.

Analysis of PDEs · Mathematics 2011-04-07 W. Arendt , A. F. M. ter Elst

Let $d_1$, $d_2$, ... be a sequence of positive numbers that converges to zero. A generalization of Steinhaus' theorem due to Weil implies that, if a subset of a homogeneous Riemannian manifold has no pair of points at distances $d_1$,…

Combinatorics · Mathematics 2013-11-19 Fernando Mário de Oliveira Filho , Frank Vallentin

We show that every de Rham cohomology class on the total space of a symplectic fiber bundle with closed Lefschetz fibers, admits a Poisson harmonic representative in the sense of Brylinski. The proof is based on a new characterization of…

Symplectic Geometry · Mathematics 2011-04-21 Oliver Ebner , Stefan Haller