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Geometry can be used to explain many properties commonly observed in real networks. It is therefore often assumed that real networks, especially those with high average local clustering, live in an underlying hidden geometric space.…

Physics and Society · Physics 2024-04-11 J. van der Kolk , M. Á. Serrano , M. Boguñá

The $\widetilde{A}_n$ Coxeter groups are known to not be systolic or cocompactly cubulated for $n\geq 3$. We prove that these groups act geometrically on weakly modular graphs, a weak notion of nonpositive curvature generalizing the…

Group Theory · Mathematics 2019-06-26 Zachary Munro

We use network theory to study topological features in the hierarchical clustering of dark matter halos. We use public halo catalogs from cosmological N-body simulations and construct tree graphs that connect halos within main halo systems.…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-22 Daneng Yang , Hai-Bo Yu

Weakly distance-regular digraphs are a natural directed version of distance-regular graphs. In [16], we classified all commutative weakly distance-regular digraphs whose underlying graphs are Hamming graphs, folded n-cubes, or Doob graphs.…

Combinatorics · Mathematics 2024-08-07 Qing Zeng , Yuefeng Yang , Kaishun Wang

The purpose of this paper is to develop a homotopical algebra for graphs, relevant to zeta series and spectra of finite graphs. More precisely, we define a Quillen model structure in a category of graphs (directed and possibly infinite,…

Combinatorics · Mathematics 2008-02-27 Terrence Bisson , Aristide Tsemo

We introduce moduli spaces of colored graphs, defined as spaces of non-degenerate metrics on certain families of edge-colored graphs. Apart from fixing the rank and number of legs these families are determined by various conditions on the…

Algebraic Topology · Mathematics 2020-08-17 Marko Berghoff , Max Mühlbauer

This is the first in a projected series of three papers in which we construct the second flip in the log minimal model program for $\bar{M}_g$. We introduce the notion of a weakly proper algebraic stack, which may be considered as an…

Algebraic Geometry · Mathematics 2015-03-17 Jarod Alper , David Ishii Smyth , Frederick van der Wyck

We construct a moduli space of four colorings on planar cubic graphs. More precisely, we introduce the notion of weak Hamiltonian, a generalization of Hamiltonian cycles, and relate it to 4-colorings. Weak Hamiltonians have a form of…

Combinatorics · Mathematics 2015-05-19 Jimmy Dillies

Similarity notions between vertices in a graph, such as structural and regular equivalence, are one of the main ingredients in clustering tools in complex network science. We generalise structural and regular equivalences for undirected…

Combinatorics · Mathematics 2026-01-01 Marzieh Eidi , Nina Otter

In this paper we introduce a family of planar, modular and self-similar graphs which have small-world and scale-free properties. The main parameters of this family are comparable to those of networks associated to complex systems, and…

Physics and Society · Physics 2008-06-10 Lichao Chen , Francesc Comellas , Zhongzhi Zhang

Modular Decomposition focuses on repeatedly identifying a module M (a collection of vertices that shares exactly the same neighbourhood outside of M) and collapsing it into a single vertex. This notion of exactitude of neighbourhood is very…

Discrete Mathematics · Computer Science 2021-01-25 Michel Habib , Lalla Mouatadid , Eric Sopena , Mengchuan Zou

The class of Euclidean unit disk graphs is one of the most fundamental and well-studied graph classes with underlying geometry. In this paper, we identify this class as a special case in the broader class of hyperbolic unit disk graphs and…

Data Structures and Algorithms · Computer Science 2022-12-16 Thomas Bläsius , Tobias Friedrich , Maximilian Katzmann , Daniel Stephan

Graph-level representations are crucial tools for characterising structural differences between graphs. However, comparing graphs with different cardinalities, even when sampled from the same underlying distribution, remains challenging.…

Machine Learning · Computer Science 2026-05-08 Katharina Limbeck , Nadja Häusermann , Martin Carrasco , Guy Wolf , Bastian Rieck

We define a weakly threshold sequence to be a degree sequence $d=(d_1,\dots,d_n)$ of a graph having the property that $\sum_{i \leq k} d_i \geq k(k-1)+\sum_{i > k} \min\{k,d_i\} - 1$ for all positive $k \leq \max\{i:d_i \geq i-1\}$. The…

Combinatorics · Mathematics 2023-06-22 Michael D. Barrus

In this paper, we want to study the link between the presence of compact objects with some analytic structure and the global geometry of a weakly complete surface. We begin with a brief survey of some now classic results on the local…

Complex Variables · Mathematics 2019-04-09 Samuele Mongodi , Giuseppe Tomassini

The main goal of this paper is proving the fixed point theorem for finite groups acting on weakly systolic complexes. As corollaries we obtain results concerning classifying spaces for the family of finite subgroups of weakly systolic…

Group Theory · Mathematics 2012-09-26 Victor Chepoi , Damian Osajda

This article studies automorphism groups of graph products of arbitrary groups. We completely characterise automorphisms that preserve the set of conjugacy classes of vertex groups as those automorphisms that can be decomposed as a product…

Group Theory · Mathematics 2019-08-07 Anthony Genevois , Alexandre Martin

We introduce shortcut graphs and groups. Shortcut graphs are graphs in which cycles cannot embed without metric distortion. Shortcut groups are groups which act properly and cocompactly on shortcut graphs. These notions unify a surprisingly…

Group Theory · Mathematics 2021-09-10 Nima Hoda

We prove measurable analogues of Whitney's classical theorems on weak isomorphisms of finite graphs. In the setting of locally finite graphings, we introduce a notion of weak isomorphism as an edge-measure-preserving Borel bijection that…

Combinatorics · Mathematics 2026-05-18 Márton Borbényi , Grigory Terlov , László Márton Tóth

Geometric graph models of systems as diverse as proteins, robots, and mechanical structures from DNA assemblies to architected materials point towards a unified way to represent and control them in space and time. While much work has been…

Robotics · Computer Science 2022-08-24 Siheng Chen , Fabio Giardina , Gary P. T. Choi , L. Mahadevan