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Decompositions of networks are useful not only for structural exploration. They also have implications and use in analysis and computational solution of processes (such as the Ising model, percolation, SIR model) running on a given network.…

Disordered Systems and Neural Networks · Physics 2020-04-29 Konstantin Klemm

We prove a general duality theorem for tangle-like dense objects in combinatorial structures such as graphs and matroids. This paper continues, and assumes familiarity with, the theory developed in [6]

Combinatorics · Mathematics 2014-06-17 Reinhard Diestel , Sang-il Oum

We provide a finite equational presentation of graphs of treewidth at most three, solving an instanceof an open problem by Courcelle and Engelfriet. We use a syntax generalising series-parallel expressions, denoting graphs with a small…

Logic in Computer Science · Computer Science 2025-01-23 Amina Doumane , Samuel Humeau , Damien Pous

The function of a real network depends not only on the reliability of its own components, but is affected also by the simultaneous operation of other real networks coupled with it. Robustness of systems composed of interdependent network…

Physics and Society · Physics 2015-07-10 Filippo Radicchi

We define the crossing graph of a given embedded graph (such as a road network) to be a graph with a vertex for each edge of the embedding, with two crossing graph vertices adjacent when the corresponding two edges of the embedding cross…

Data Structures and Algorithms · Computer Science 2017-09-20 David Eppstein , Siddharth Gupta

We prove that every graph has a canonical tree of tree-decompositions that distinguishes all principal tangles (these include the ends and various kinds of large finite dense structures) efficiently. Here `trees of tree-decompositions' are…

Combinatorics · Mathematics 2020-04-08 Johannes Carmesin , Matthias Hamann , Babak Miraftab

We consider infinite connected quasi-transitive locally finite graphs and show that every such graph with more than one end is a tree amalgamation of two other such graphs. This can be seen as a graph-theoretical version of Stallings'…

Combinatorics · Mathematics 2019-06-19 Matthias Hamann , Florian Lehner , Babak Miraftab , Tim Rühmann

Context: Edge graphs are graphs whose edges are labelled with identifiers, and nodes can have multiple edges between them. They are used to model a wide range of systems, including networks with distances or degrees of connection and…

Programming Languages · Computer Science 2024-03-05 Jack Liell-Cock , Tom Schrijvers

We present infinite analogues of our splinter lemma from [Trees of tangles in abstract separation systems, arXiv:1909.09030]. From these we derive several tree-of-tangles-type theorems for infinite graphs and infinite abstract separation…

Combinatorics · Mathematics 2025-05-16 Christian Elbracht , Jay Lilian Kneip , Maximilian Teegen

Transductions are a general formalism for expressing transformations of graphs (and more generally, of relational structures) in logic. We prove that a graph class $\mathscr{C}$ can be $\mathsf{FO}$-transduced from a class of bounded-height…

Combinatorics · Mathematics 2022-04-01 Michał Pilipczuk , Patrice Ossona de Mendez , Sebastian Siebertz

We construct tree-decompositions of graphs that distinguish all their k-blocks and tangles of order k, for any fixed integer k. We describe a family of algorithms to construct such decompositions, seeking to maximize their diversity subject…

Combinatorics · Mathematics 2014-04-25 Johannes Carmesin , Reinhard Diestel , Matthias Hamann , Fabian Hundertmark

The notion of forbidden-transition graphs allows for a robust generalization of walks in graphs. In a forbidden-transition graph, every pair of edges incident to a common vertex is permitted or forbidden; a walk is compatible if all pairs…

Data Structures and Algorithms · Computer Science 2020-09-29 Thomas Bellitto , Shaohua Li , Karolina Okrasa , Marcin Pilipczuk , Manuel Sorge

We present a canonical way to decompose finite graphs into highly connected local parts. The decomposition depends only on an integer parameter whose choice sets the intended degree of locality. The global structure of the graph, as…

Combinatorics · Mathematics 2025-07-01 Reinhard Diestel , Raphael W. Jacobs , Paul Knappe , Jan Kurkofka

Roberston and Seymour introduced tangles of order $k$ as objects representing highly connected parts of a graph and showed that every graph admits a tree-decomposition of adhesion $<k$ in which each tangle of order $k$ is contained in a…

Combinatorics · Mathematics 2017-03-06 Joshua Erde

A traversal of a connected graph is a linear ordering of its vertices all of whose initial segments induce connected subgraphs. Traversals, and their refinements such as breadth-first and depth-first traversals, are computed by various…

Logic · Mathematics 2018-10-24 Siddharth Bhaskar , Anton Jay Kienzle

We study spreading processes in temporal graphs, i. e., graphs whose connections change over time. These processes naturally model real-world phenomena such as infectious diseases or information flows. More precisely, we investigate how…

Data Structures and Algorithms · Computer Science 2021-07-21 Hendrik Molter , Malte Renken , Philipp Zschoche

We study varieties associated to hypergraphs from the point of view of projective geometry and matroid theory. We describe their decompositions into matroid varieties, which may be reducible and can have arbitrary singularities by the…

Combinatorics · Mathematics 2025-12-18 Oliver Clarke , Kevin Grace , Fatemeh Mohammadi , Harshit J Motwani

We prove a duality theorem applicable to a a wide range of specialisations, as well as to some generalisations, of tangles in graphs. It generalises the classical tangle duality theorem of Robertson and Seymour, which says that every graph…

Combinatorics · Mathematics 2017-07-07 Reinhard Diestel , Philipp Eberenz , Joshua Erde

We generalize the well-studied notion of a modular pair of a finite matroid to arbitrary families of sets in infinite matroids, and use it to develop the theory of infinite matroids in several as-yet-unexplored areas. Our results include a…

Combinatorics · Mathematics 2026-04-23 Mattias Ehatamm , Peter Nelson , Fernanda Rivera Omana

In this paper it is shown that for any network there is a uniquely determined network based on a structure tree that provides a convenient way of determining a minimal cut separating a pair $s, t$ where each of $s, t$ is either a vertex or…

Combinatorics · Mathematics 2015-01-05 M. J. Dunwoody