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Let $G$ be a finite simple graph. The line graph $L(G)$ represents the adjacencies between edges of $G$. We define first the line simplicial complex $\Delta_L(G)$ of $G$ containing Gallai and anti-Gallai simplicial complexes…

Algebraic Topology · Mathematics 2017-08-04 Imran Ahmed , Shahid Muhmood

We study different geometric properties on infinite graphs, related to the weak-type boundedness of the Hardy-Littlewood maximal averaging operator. In particular, we analyze the connections between the doubling condition, having finite…

Classical Analysis and ODEs · Mathematics 2016-02-03 Javier Soria , Pedro Tradacete

These notes loosely follow an introductory course on graph complexes, held at Humboldt-Universit\"at zu Berlin in summer 23. Instead of simply typing up my lecture notes I decided to give here an overview over (parts of) the topic (lecture…

Algebraic Topology · Mathematics 2023-12-19 Marko Berghoff

A Helly circular-arc graph is the intersection graph of a set of arcs on a circle having the Helly property. We introduce essential obstacles, which are a refinement of the notion of obstacles, and prove that essential obstacles are…

Combinatorics · Mathematics 2021-08-31 Martín D. Safe

Weakly distance-regular digraphs are a natural directed version of distance-regular graphs. In [8], the third author and Suzuki proposed a question when an orientation of a distance-regular graph defines a weakly distance-regular digraph.…

Combinatorics · Mathematics 2024-04-11 Yuefeng Yang , Qing Zeng , Kaishun Wang

Weakly separated collections arise in the cluster algebra derived from the Pl\"ucker coordinates on the nonnegative Grassmannian. Oh, Postnikov, and Speyer studied weakly separated collections over a general Grassmann necklace $\mathcal{I}$…

Combinatorics · Mathematics 2016-08-23 Meena Jagadeesan

A 3-dimensional graph-manifold is composed from simple blocks which are products of compact surfaces with boundary by the circle. Its global structure may be as complicated as one likes and is described by a graph which might be an…

Mathematical Physics · Physics 2007-05-23 Sergei Buyalo

A graph is Helly if every family of pairwise intersecting balls has a nonempty common intersection. The class of Helly graphs is the discrete analogue of the class of hyperconvex metric spaces. It is also known that every graph…

Data Structures and Algorithms · Computer Science 2021-02-17 Feodor F. Dragan , Guillaume Ducoffe , Heather M. Guarnera

In this survey, we explore recent literature on finding the cores of higher graphs using geometric and topological means. We study graphs, hypergraphs, and simplicial complexes, all of which are models of higher graphs. We study the notion…

History and Overview · Mathematics 2025-06-30 Inés García-Redondo , Claudia Landi , Sarah Percival , Anda Skeja , Bei Wang , Ling Zhou

The low energy expansion of Type II superstring amplitudes at genus one is organized in terms of modular graph functions associated with Feynman graphs of a conformal scalar field on the torus. In earlier work, surprising identities between…

High Energy Physics - Theory · Physics 2017-10-16 Eric D'Hoker , Justin Kaidi

We give characterizations for the failure of form uniqueness on weakly spherically symmetric graphs. The first characterization is in terms of the graph structure, the second involves the capacity of a Cauchy boundary. We also discuss the…

Mathematical Physics · Physics 2025-09-30 Luis Hernandez , Sean Ku , Jun Masamune , Genevieve Romanelli , Radosław K. Wojciechowski

The median function is a location/consensus function that maps any profile $\pi$ (a finite multiset of vertices) to the set of vertices that minimize the distance sum to vertices from $\pi$. The median function satisfies several simple…

Combinatorics · Mathematics 2026-02-17 Laurine Bénéteau , Jérémie Chalopin , Victor Chepoi , Yann Vaxès

Graph-based signal processing techniques have become essential for handling data in non-Euclidean spaces. However, there is a growing awareness that these graph models might need to be expanded into `higher-order' domains to effectively…

Machine Learning · Computer Science 2024-04-15 Mustafa Hajij , Ghada Zamzmi , Theodore Papamarkou , Aldo Guzmán-Sáenz , Tolga Birdal , Michael T. Schaub

In this article we introduce the notion of weak harmonic labeling of a graph, a generalization of the concept of harmonic labeling defined recently by Benjamini et al. that allows extension to finite graphs and graphs with leaves. We…

Combinatorics · Mathematics 2020-12-01 Pablo Leandro Bonucci , Nicolás Ariel Capitelli

In the suborbital graphs studies, there has been a research gap in the sense that the Modular group is connected to two numbers. Thus, this paper attempts to contribute to the studies developed by Gauss, Bolyai, Lobachevsky and Riemann.…

General Mathematics · Mathematics 2025-12-09 Ibrahim Gokcan , Ali Hikmet Deger

On R^n endowed with a riemannian metric of bounded nonpositive curvature, the weakly convex closed subsets are topologically trivial. The stability of such subsets under intersection characterizes the euclidean spaces.

Differential Geometry · Mathematics 2016-09-07 Stephane Grognet

Real-world graphs generally have only one kind of tendency in their connections. These connections are either homophily-prone or heterophily-prone. While graphs with homophily-prone edges tend to connect nodes with the same class (i.e.,…

Social and Information Networks · Computer Science 2023-06-14 Yizhen Zheng , He Zhang , Vincent CS Lee , Yu Zheng , Xiao Wang , Shirui Pan

We present a homotopy theory for a weak version of modular operads whose compositions and contractions are only defined up to homotopy. This homotopy theory takes the form of a Quillen model structure on the collection of simplicial…

Algebraic Topology · Mathematics 2020-07-03 Philip Hackney , Marcy Robertson , Donald Yau

We study Helly graphs of finite combinatorial dimension, i.e. whose injective hull is finite-dimensional. We describe very simple fine simplicial subdivisions of the injective hull of a Helly graph, following work of Lang. We also give a…

Combinatorics · Mathematics 2023-10-18 Thomas Haettel

A graph $G$ is weakly $\gamma$-closed if every induced subgraph of $G$ contains one vertex $v$ such that for each non-neighbor $u$ of $v$ it holds that $|N(u)\cap N(v)|<\gamma$. The weak closure $\gamma(G)$ of a graph, recently introduced…

Discrete Mathematics · Computer Science 2022-11-04 Tomohiro Koana , Christian Komusiewicz , Frank Sommer