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Related papers: Ricci curvature, graphs and eigenvalues

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We give a sharp bound for the automorphism group of a cubic simple graph with a given number of vertices. For each number of vertices we give an explicit graph attaining the bound, and prove its uniqueness in special cases.

Combinatorics · Mathematics 2007-05-23 Michael A. van Opstall , Razvan Veliche

We define a hybrid between Ollvier and Bakry Emery curvature on graphs with dependence on a variable neighborhood. The hexagonal lattice is non-negatively curved under this new curvature notion. Bonnet-Myers diameter bounds and Lichnerowicz…

Combinatorics · Mathematics 2019-06-17 Mark Kempton , Gabor Lippner , Florentin Munch

In this paper, we introduce a unified framework for defining Lin-Lu-Yau (LLY) Ricci curvature on both undirected and directed hypergraphs. By establishing upper bounds and monotonicity properties for the parameterized curvature…

Differential Geometry · Mathematics 2025-07-08 Yulu Tian , Liang Zhao

In this note we discuss the fundamental groups and diameters of positively Ricci curved $n$-manifolds. We use a method combining the results about equivarient Hausdorff convergence developed by Fukaya and Yamaguchi with the Ricci version of…

Differential Geometry · Mathematics 2007-05-23 Wen-Haw Chen , Jyh-Yang Wu

We define the notion of rough Cayley graph for compactly generated locally compact groups in terms of quasi-actions. We construct such a graph for any compactly generated locally compact group using quasi-lattices and show uniqueness up to…

Group Theory · Mathematics 2013-08-07 Pekka Salmi

We define the Ricci curvature of Markov chains on metric spaces as a local contraction coefficient of the random walk acting on the space of probability measures equipped with a Wasserstein transportation distance. For Brownian motion on a…

Probability · Mathematics 2007-07-30 Yann Ollivier

Lin-Lu-Yau introduced an interesting notion of Ricci curvature for graphs and obtained a complete characterization for all Ricci-flat graphs with girth at least five [1]. In this paper, we propose a concrete approach to construct an…

Combinatorics · Mathematics 2018-07-20 Weihua He , Jun Luo , Chao Yang , Wei Yuan

A comparison theorem for the isoperimetric profile on the universal cover of surfaces evolving by normalised Ricci flow is proven. For any initial metric, a model comparison is constructed that initially lies below the profile of the…

Differential Geometry · Mathematics 2014-04-24 Paul Bryan

In this article, we introduce a $2$-parameter family of affine connections and derive the Ricci curvature. We first establish an integral Bochner technique. On one hand, this technique yields a new proof to our recent work in \cite{LX} for…

Differential Geometry · Mathematics 2017-05-30 Junfang Li , Chao Xia

We describe the exponential map from an infinite-dimensional Lie algebra to an infinite-dimensional group of operators on a Hilbert space. Notions of differential geometry are introduced for these groups. In particular, the Ricci curvature,…

Differential Geometry · Mathematics 2007-05-23 Maria Gordina

We prove diameter bounds for graphs having positive Ricci-curvature bound in Bakry-Emery sense. One result using only curvature and maximal vertex degree is sharp in case of hypercubes. The other result depends on an additional dimension…

Differential Geometry · Mathematics 2019-04-03 Shiping Liu , Florentin Münch , Norbert Peyerimhoff

We develop a systematical way of constructing S-Ricci flat graphs which are not Abelian Cayley via graph bundle with explicit examples. For this purpose, we prove that, with some natural constrains, a non-trivial graph bundle can not be…

Differential Geometry · Mathematics 2025-02-14 Wenbo Li , Shiping Liu

In this paper, we consider the Ricci flow with prescribed curvature on the finite graph $G=(V,E)$. For any $e$ in $E$, $$\frac{d\omega(t,e)}{dt} = -(\kappa(t,e)-\kappa^*(e))\omega(t,e), t > 0,$$ where $\omega$ is the weight function,…

Differential Geometry · Mathematics 2026-04-21 Yong Lin , Shuang Liu

Community detection is an important problem in graph neural networks. Recently, algorithms based on Ricci curvature flows have gained significant attention. It was suggested by Ollivier (2009), and applied to community detection by Ni et al…

Analysis of PDEs · Mathematics 2025-05-22 Jicheng Ma , Yunyan Yang

We present conditions on the Ricci curvature for complete, oriented, minimal submanifolds of Euclidean space, as well as the standard unit sphere, when the Gauss maps are bounded embeddings.

Differential Geometry · Mathematics 2009-09-15 Richard Atkins

A graph is called Ricci-flat if its Ricci curvatures vanish on all edges, here the definition of Ricci curvature on graphs was given by Lin-Lu-Yau. The authors in arXiv:1301.0102 and arXiv:1802.02982 obtained a complete characterization for…

Differential Geometry · Mathematics 2021-05-11 Shuliang Bai , Linyuan Lu , Shing-Tung Yau

Let $M$ denote a low-dimensional manifold embedded in Euclidean space and let ${X}= \{ x_1, \dots, x_n \}$ be a collection of points uniformly sampled from it. We study the relationship between the curvature of a random geometric graph…

Differential Geometry · Mathematics 2024-08-27 Nicolas Garcia Trillos , Melanie Weber

We derive explicit formulas for the Lin-Lu-Yau curvature and the Ollivier-Ricci curvature in terms of graph parameters and an optimal assignment. Utilizing these precise expressions, we examine the relationship between the Lin-Lu-Yau…

Combinatorics · Mathematics 2024-12-06 Moritz Hehl

Motivated by the methods and results of manifold sampling based on Ricci curvature, we propose a similar approach for networks. To this end we make appeal to three types of discrete curvature, namely the graph Forman-, full Forman- and…

Differential Geometry · Mathematics 2021-03-05 Vladislav Barkanass , Jürgen Jost , Emil Saucan

For any finite, undirected, non-bipartite, vertex-transitive graph, we establish an explicit lower bound for the smallest eigenvalue of its normalised adjacency operator, which depends on the graph only through its degree and its…

Combinatorics · Mathematics 2022-02-09 Arindam Biswas , Jyoti Prakash Saha