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Related papers: Convex isoperimetric sets in the Heisenberg group

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We study properties of 3-restricted min-wise independent sets of permutations and prove that the class of these sets is isomorphic to the class of subsets of vertices of multi-dimentional hypercube of certain size with certain pair-wise…

Combinatorics · Mathematics 2015-12-29 Victor Bargachev

As a consequence of Kirchberg's work, Connes' Embedding Conjecture is equivalent to the property that every homomorphism of the group $F_\infty\times F_\infty$ into the unitary group $U(\ell^2)$ with the strong topology is pointwise…

Representation Theory · Mathematics 2021-08-31 Vladimir G. Pestov , Vladimir V. Uspenskij

We initiate the study of convex geometry over ordered hyperfields. We define convex sets and halfspaces over ordered hyperfields, presenting structure theorems over hyperfields arising as quotients of fields. We prove hyperfield analogues…

Metric Geometry · Mathematics 2025-09-24 James Maxwell , Ben Smith

We prove asymptotically isometric, coarsely geodesic metrics on a toral relatively hyperbolic group are coarsely equal. The theorem applies to all lattices in SO(n,1). This partly verifies a conjecture by Margulis. In the case of hyperbolic…

Group Theory · Mathematics 2013-11-18 Koji Fujiwara

In this paper, we study a reverse isoperimetric inequality for planar convex bodies whose radius of curvature is between two positive numbers 0 < $\alpha$ < $\beta$, called ($\alpha$, $\beta$)--convex bodies. We show that among planar…

Optimization and Control · Mathematics 2022-03-10 Gisella Croce , Zakaria Fattah , Giovanni Pisante

We initiate a classification of uniform measures in the first Heisenberg group $\mathbb H$ equipped with the Kor\'anyi metric $d_H$, that represents the first example of a noncommutative stratified group equipped with a homogeneous…

Metric Geometry · Mathematics 2023-12-12 Vasilis Chousionis , Valentino Magnani , Jeremy T. Tyson

In this paper, we study bijections on strictly convex sets of $\mathbf R \mathbf P^n$ for $n \geq 2$ and closed convex projective surfaces equipped with the Hilbert metric that map complete geodesics to complete geodesics as sets.…

Metric Geometry · Mathematics 2022-09-13 Drimik Roy Chowdhury

We construct convex bodies that can be "captured by nets." More precisely, for each dimension $n \geq 2$, we construct a family of Riemannian $n$-spheres, each with a stable geodesic net, which is a stable 1-dimensional integral varifold.…

Differential Geometry · Mathematics 2023-12-01 Herng Yi Cheng

We prove that every finite group is the automorphism group of a finite abstract polytope isomorphic to a face-to-face tessellation of a sphere by topological copies of convex polytopes. We also show that this abstract polytope may be…

Combinatorics · Mathematics 2015-05-26 Egon Schulte , Gordon Ian Williams

Let $\mathcal{X}_S$ denote the class of spaces homeomorphic to two closed orientable surfaces of genus greater than one identified to each other along an essential simple closed curve in each surface. Let $\mathcal{C}_S$ denote the set of…

Geometric Topology · Mathematics 2015-11-04 Emily Stark

We study the boundaries of relatively hyperbolic HHGs. Using the simplicial structure on the hierarchically hyperbolic boundary, we characterize both relative hyperbolicity and being thick of order 1 among HHGs. In the case of relatively…

Group Theory · Mathematics 2023-05-29 Carolyn Abbott , Jason Behrstock , Jacob Russell

Let $\Omega$ be a bounded, convex domain in a separable Hilbert space. The authors prove a version of the theorem of Bun Wong, which asserts that if such a domain admits an automorphism orbit accumulating at a strongly pseudoconvex boundary…

Complex Variables · Mathematics 2007-05-23 Kang-Tae Kim , Steven G. Krantz

We consider mappings between Carnot groups. In this paper, which is a continuation of "Pansu pullback and rigidity of mappings between Carnot groups" (arXiv:2004.09271), we focus on Carnot groups which are nonrigid in the sense of…

Differential Geometry · Mathematics 2021-12-06 Bruce Kleiner , Stefan Muller , Xiangdong Xie

We introduce a strong notion of quasiconvexity in finitely generated groups, which we call stability. Stability agrees with quasiconvexity in hyperbolic groups and is preserved under quasi-isometry for finitely generated groups. We show…

Geometric Topology · Mathematics 2015-11-25 Matthew Gentry Durham , Samuel J. Taylor

We provide a partial solution to the isoperimetric problem in the Heisenberg group.

Differential Geometry · Mathematics 2007-05-23 N. Garofalo , D. Danielli , D. M. Nhieu

On a convex set, we prove that the Poincar\'e-Sobolev constant for functions vanishing at the boundary can be bounded from above by the ratio between the perimeter and a suitable power of the $N-$dimensional measure. This generalizes an old…

Optimization and Control · Mathematics 2019-03-12 Lorenzo Brasco

A representation of a finitely generated group into the projective general linear group is called convex co-compact if it has finite kernel and its image acts convex co-compactly on a properly convex domain in real projective space. We…

Geometric Topology · Mathematics 2024-03-19 Mitul Islam , Andrew Zimmer

We construct uncountably many isoparametric families of hypersurfaces in Damek-Ricci spaces. We characterize those of them that have constant principal curvatures by means of the new concept of generalized Kahler angle. It follows that, in…

Differential Geometry · Mathematics 2012-10-03 J. Carlos Diaz-Ramos , Miguel Dominguez-Vazquez

Motivated by the desire of finding a geometric interpretation to the Yamabe equation on groups of Heisenberg type, we define a geometric structure on manifolds modelled locally on these groups, which we call contact structure of Heisenberg…

Differential Geometry · Mathematics 2026-01-13 Claudio Afeltra

We establish a family of parametric isoperimetric-type inequalities with multiple geometric quantities for closed convex curves. These inequalities hold under certain parameter conditions. We also prove the equality conditions. Some new…

Differential Geometry · Mathematics 2026-05-28 Heran Zhao