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相关论文: A note on a Bonnet-Myers type diameter bound for g…

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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…

微分几何 · 数学 2019-04-03 Shiping Liu , Florentin Münch , Norbert Peyerimhoff

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…

微分几何 · 数学 2017-05-22 Shiping Liu , Florentin Münch , Norbert Peyerimhoff

In this paper, we derive new sharp diameter bounds for distance regular graphs, which better answer a problem raised by Neumaier and Penji\' c in many cases. Our proof is built upon a relation between the diameter and long-scale Ollivier…

组合数学 · 数学 2025-09-01 Kaizhe Chen , Shiping Liu

In a previous work, the authors have introduced a Lin-Lu-Yau type Ricci curvature for directed graphs, and obtained a diameter comparison of Bonnet-Myers type. In this paper, we investigate rigidity properties for the equality case, and…

微分几何 · 数学 2021-04-26 Ryunosuke Ozawa , Yohei Sakurai , Taiki Yamada

We prove distance bounds for graphs possessing positive Bakry-\'Emery curvature apart from an exceptional set, where the curvature is allowed to be non-positive. If the set of non-positively curved vertices is finite, then the graph admits…

微分几何 · 数学 2019-03-26 Shiping Liu , Florentin Münch , Norbert Peyerimhoff , Christian Rose

We introduce the notion of Bonnet-Myers and Lichnerowicz sharpness in the Ollivier Ricci curvature sense. Our main result is a classification of all self-centered Bonnet-Myers sharp graphs (hypercubes, cocktail party graphs,…

In this note, we prove that positive scalar curvature can pass to three dimensional Ricci limit spaces of non-negative Ricci curvature when it splits off a line. As a corollary, we obtain an optimal Bonnet-Myers type upper bound. Moreover,…

微分几何 · 数学 2023-03-28 Bo Zhu , Xingyu Zhu

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…

组合数学 · 数学 2019-06-17 Mark Kempton , Gabor Lippner , Florentin Munch

In this paper, we propose a generalization of Bakry-\'Emery's calculus which allows us to formulate both Bakry-\'Emery and entropic curvature simultaneously. This formulation represents both curvatures as an integral of the Bochner formula…

微分几何 · 数学 2023-12-18 Supanat Kamtue , Shiping Liu , Florentin Münch , Norbert Peyerimhoff

In this article we prove that antitrees with suitable growth properties are examples of infinite graphs exhibiting strictly positive curvature in various contexts: in the normalized and non-normalized Bakry-\'Emery setting as well in the…

组合数学 · 数学 2018-01-30 David Cushing , Shiping Liu , Florentin Münch , Norbert Peyerimhoff

In this paper we establish new simple local geometric criteria for discrete entropic curvature introduced in [47] that are powerful enough to capture many geometric properties of complex models arising in mathematical physics. These results…

概率论 · 数学 2024-07-01 Martin Rapaport , Paul-Marie Samson

In this paper, we present extensions of the classical Bonnet-Myers theorem for Riemannian manifolds with nonnegative Ricci curvature. Our results provide criteria for compactness and a method for estimating the diameter of such manifolds…

微分几何 · 数学 2025-09-03 Ronggang Li , Shaoqing Wang

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…

微分几何 · 数学 2025-07-08 Yulu Tian , Liang Zhao

In this paper we prove a new Myers' type diameter estimate on a complete connected Reimannian manifold which admits a bounded vector field such that the Bakry-\'Emery Ricci tensor has a positive lower bound. The result is sharper than…

微分几何 · 数学 2018-05-16 Jia-Yong Wu

In this paper, we shall give a new upper diameter estimate for complete Riemannian manifolds in the case that the Bakry-\'Emery Ricci curvature has a positive lower bound and the norm of the potential function has an upper bound. Our…

微分几何 · 数学 2015-11-10 Homare Tadano

In this paper, we establish a simple formula for computing the Lin-Lu-Yau Ricci curvature on graphs. For any edge $xy$ in a simple locally finite graph $G$, the curvature $\kappa(x,y)$ can be expressed as a cost function of an optimal…

组合数学 · 数学 2024-11-25 Yupei Li , Linyuan Lu

Amply regular graphs are graphs with local distance-regularity constraints. In this paper, we prove a weaker version of a conjecture proposed by Qiao, Park, and Koolen on diameter bounds of amply regular graphs and make new progress on…

微分几何 · 数学 2025-07-08 Kaizhe Chen , Chunyang Hu , Shiping Liu , Heng Zhang

In this paper we consider global $\theta$-curvatures of finite Markov chains with associated means $\theta$ in the spirit of the entropic curvature (based on the logarithmic mean) by Erbar-Maas and Mielke. As in the case of Bakry-\'Emery…

微分几何 · 数学 2025-04-01 Supanat Kamtue , Shiping Liu , Florentin Münch , Norbert Peyerimhoff

We give a discrete Bonnet Myers type theorem for the effective diameter assuming positive Ollivier curvature. We prove that this diameter bound is attained if and only if the graph is a cocktail party graph, a Johnson graph, a halved cube,…

组合数学 · 数学 2022-06-01 Florentin Münch

We study a new notion of Ricci curvature that applies to Markov chains on discrete spaces. This notion relies on geodesic convexity of the entropy and is analogous to the one introduced by Lott, Sturm, and Villani for geodesic measure…

度量几何 · 数学 2015-06-03 Matthias Erbar , Jan Maas
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