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We introduce a notion of curvature on finite, combinatorial graphs. It can be easily computed by solving a linear system of equations. We show that graphs with curvature bounded below by $K>0$ have diameter bounded by $\mbox{diam}(G) \leq…

Combinatorics · Mathematics 2022-09-07 Stefan Steinerberger

For matrix analogues of embedded surfaces we define discrete curvatures and Euler characteristics, and a non-commutative Gauss--Bonnet theorem is shown to follow. We derive simple expressions for the discrete Gauss curvature in terms of…

Mathematical Physics · Physics 2010-01-20 Joakim Arnlind , Jens Hoppe , Gerhard Huisken

We give rigidity results for the discrete Bonnet-Myers diameter bound and the Lichnerowicz eigenvalue estimate. Both inequalities are sharp if and only if the underlying graph is a hypercube. The proofs use well-known semigroup methods as…

Differential Geometry · Mathematics 2017-05-22 Shiping Liu , Florentin Münch , Norbert Peyerimhoff

In this paper we consider higher isoperimetric numbers of a (finite directed) graph. In this regard we focus on the $n$th mean isoperimetric constant of a directed graph as the minimum of the mean outgoing normalized flows from a given set…

Combinatorics · Mathematics 2015-02-03 Amir Daneshgar , Hossein Hajiabolhassan , Ramin Javadi

We prove the Li-Yau gradient estimate for the heat kernel on graphs. The only assumption is a variant of the curvature-dimension inequality, which is purely local, and can be considered as a new notion of curvature for graphs. We compute…

Analysis of PDEs · Mathematics 2015-12-02 Frank Bauer , Paul Horn , Yong Lin , Gabor Lippner , Dan Mangoubi , Shing-Tung Yau

We investigate isoperimetric constants of infinite tessellating metric graphs. We introduce a curvature-like quantity, which plays the role of a metric graph analogue of discrete curvature notions for combinatorial tessellating graphs. We…

Metric Geometry · Mathematics 2018-06-27 Noema Nicolussi

We extend several Cheeger-type isoperimetric bounds for convex sets in Euclidean space, due to Bobkov and Kannan-Lov\'asz-Simonovits, to Riemannian manifolds having non-negative Ricci curvature. In order to extend Bobkov's bound, we require…

Functional Analysis · Mathematics 2011-05-06 Emanuel Milman

The graph Cheeger constant and Cheeger inequalities are generalized to the case of hypergraphs whose edges have the same cardinality. In particular, it is shown that the second largest eigenvalue of the generalized normalized Laplacian is…

Combinatorics · Mathematics 2021-06-08 Raffaella Mulas

Fix an ordinary abelian variety defined over a finite field. The ideal class group of its endomorphism ring acts freely on the set of isogenous varieties with same endomorphism ring, by complex multiplication. Any subgroup of the class…

Number Theory · Mathematics 2017-01-26 Dimitar Jetchev , Benjamin Wesolowski

In this paper, we introduce Cheeger type constants via isocapacitary constants introduced by Maz'ya to estimate first Dirichlet, Neumann and Steklov eigenvalues on a finite subgraph of a graph. Moreover, we estimate the bottom of the…

Differential Geometry · Mathematics 2024-10-08 Bobo Hua , Florentin Münch , Tao Wang

Let M be a bounded domain of a Euclidian space with smooth boundary. We relate the Cheeger constant of M and the conductance of a neighborhood graph defined on a random sample from M. By restricting the minimization defining the latter over…

Statistics Theory · Mathematics 2013-03-05 Ery Arias-Castro , Bruno Pelletier , Pierre Pudlo

We study a notion of curvature for finitely generated groups which serves as a role of Ricci curvature for Riemannian manifolds. We prove an analog of Cheeger-Gromoll splitting theorem. As a consequence, we give a geometric characterization…

Group Theory · Mathematics 2023-02-15 Thang Nguyen , Shi Wang

We introduce a notion of Ricci curvature for Cayley graphs that can be thought of as "medium-scale" because it is neither infinitesimal nor asymptotic, but based on a chosen finite radius parameter. We argue that it gives the foundation for…

Group Theory · Mathematics 2020-07-06 Assaf Bar-Natan , Moon Duchin , Robert Kropholler

In this paper, we reformulate the Bakry-\'Emery curvature on a weighted graph in terms of the smallest eigenvalue of a rank one perturbation of the so-called curvature matrix using Schur complement. This new viewpoint allows us to show…

Combinatorics · Mathematics 2022-01-26 David Cushing , Supanat Kamtue , Shiping Liu , Norbert Peyerimhoff

We consider quasirandom properties for Cayley graphs of finite abelian groups. We show that having uniform edge-distribution (i.e., small discrepancy) and having large eigenvalue gap are equivalent properties for such Cayley graphs, even if…

Combinatorics · Mathematics 2016-10-21 Yoshiharu Kohayakawa , Vojtěch Rödl , Mathias Schacht

Liu, M\"unch, and Peyerimhoff introduced the notion of Bakry-\'Emery curvature for connection graphs as a means to derive Buser-type bounds on the eigenvalues of connection Laplacians. In this work, we present a reformulation of the…

Combinatorics · Mathematics 2026-04-08 Chunyang Hu , Shiping Liu

In this survey, we study three different notions of curvature that are defined on graphs, namely, combinatorial curvature, Bakry-\'Emery curvature, and Ollivier's Ricci curvature. For each curvature notion, the definition and its motivation…

Combinatorics · Mathematics 2018-03-26 Supanat Kamtue

In the present paper, we propose a new discrete surface theory on 3-valent embedded graphs in the 3-dimensional Euclidean space which are not necessarily discretization or approximation of smooth surfaces. The Gauss curvature and the mean…

Differential Geometry · Mathematics 2016-01-28 Motoko Kotani , Hisashi Naito , Toshiaki Omori

We study functional inequalities for Markov chains on discrete spaces with entropic Ricci curvature bounded from below. Our main results are that when curvature is non-negative, but not necessarily positive, the spectral gap, the Cheeger…

Probability · Mathematics 2016-12-05 Matthias Erbar , Max Fathi

We consider a general theory of curvatures of discrete surfaces equipped with edgewise parallel Gauss images, and where mean and Gaussian curvatures of faces are derived from the faces' areas and mixed areas. Remarkably these notions are…

Differential Geometry · Mathematics 2017-09-06 Alexander I. Bobenko , Helmut Pottmann , Johannes Wallner