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Related papers: Trees of tangles in infinite separation systems

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A result about spanning forests for graphs yields a short proof of Krebes's theorem concerning embedded tangles in links.

Geometric Topology · Mathematics 2018-03-05 Daniel S. Silver , Susan G. Williams

We generalise structure tree theory, which is based on removing finitely many edges, to removing finitely many vertices. This gives a significant generalization of Tutte's tree decomposition of 2-connected graphs into 3-connected blocks.…

Group Theory · Mathematics 2015-01-05 M. J. Dunwoody , B. Krön

Abstract separation systems provide a simple general framework in which both tree-shape and high cohesion of many combinatorial structures can be expressed, and their duality proved. Applications range from tangle-type duality and tree…

Combinatorics · Mathematics 2017-04-19 Reinhard Diestel

We give new general formulas for the asymptotics of the number of spanning trees of a large graph. A special case answers a question of McKay (1983) for regular graphs. The general answer involves a quantity for infinite graphs that we call…

Combinatorics · Mathematics 2010-04-27 Russell Lyons

In this paper, we introduce two families of planar and self-similar graphs which have small-world properties. The constructed models are based on an iterative process where each step of a certain formulation of modules results in a final…

Combinatorics · Mathematics 2024-04-19 Muhammed Alaa Morsy , Mohamed Anwar , Abdallah Aboutahoun

In previous work, the author defined the intersection graph of a chord diagram associated with string links (as in the theory of finite type invariants). In this paper, we classify the trees which can be obtained as intersection graphs of…

Geometric Topology · Mathematics 2007-05-23 Blake Mellor

We study separating systems of the edges of a graph where each member of the separating system is a path. We conjecture that every $n$-vertex graph admits a separating path system of size $O(n)$ and prove this in certain interesting special…

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

We prove that Menger's theorem is valid for infinite graphs, in the following strong form: let $A$ and $B$ be two sets of vertices in a possibly infinite digraph. Then there exist a set $\cp$ of disjoint $A$-$B$ paths, and a set $S$ of…

Combinatorics · Mathematics 2007-12-03 Ron Aharoni , Eli Berger

Extending the well-known star-comb lemma for infinite graphs, we characterise the graphs that do not contain an infinite comb or an infinite star, respectively, attached to a given set of vertices. We offer several characterisations: in…

Combinatorics · Mathematics 2021-08-09 Carl Bürger , Jan Kurkofka

Tree sets are posets with additional structure that generalize tree-like objects in graphs, matroids, or other combinatorial structures. They are a special class of abstract separation systems. We study infinite tree sets and how they…

Combinatorics · Mathematics 2025-05-16 Jay Lilian Kneip

We show that, for any graph or matroid, there is a tree that simultaneously distinguishes its maximal tangles, and, for each maximal tangle $\mathcal{T}$ that satisfies an additional robustness condition, displays all of the non-trivial…

Combinatorics · Mathematics 2016-05-23 Ben Clark

A self-contained account of the theory of structure trees for edge cuts in networks is given. Applications include a generalisation of the Max-Flow Min-Cut Theorem to infinite networks and a short proof of a conjecture of Kropholler. This…

Combinatorics · Mathematics 2016-01-27 M. J. Dunwoody

While finite graphs have tree-decompositions that efficiently distinguish all their tangles, locally finite graphs with thick ends need not have such tree-decompositions. We show that every locally finite graph without thick ends admits…

Combinatorics · Mathematics 2024-03-25 Raphael W. Jacobs , Paul Knappe

A few notes about infinite trees in a descriptive set-theoretic setting.

Logic · Mathematics 2025-05-13 Alexandre Goy

Initial steps in the study of inner expansion properties of infinite Cayley graphs and other infinite graphs, such as hyperbolic ones, are taken, in a flavor similar to the well-known Lipton-Tarjan square root separation result for planar…

Metric Geometry · Mathematics 2011-09-14 Itai Benjamini , Oded Schramm , Adam Timar

We give a common matroidal generalisation of `A Cantor-Bernstein theorem for paths in graphs' by Diestel and Thomassen and `A Cantor-Bernstein-type theorem for spanning trees in infinite graphs' by ourselves.

Combinatorics · Mathematics 2022-05-10 Attila Joó

The Pathwidth Theorem states that if a class of graphs has unbounded pathwidth, then it contains all trees as graph minors. We prove a similar result for dense graphs. More precisely, we give a finite family of tree-like patterns and prove…

Logic in Computer Science · Computer Science 2026-04-09 Mikołaj Bojańczyk , Pierre Ohlmann

We study an abstract notion of tree structure which lies at the common core of various tree-like discrete structures commonly used in combinatorics: trees in graphs, order trees, nested subsets of a set, tree-decompositions of graphs and…

Combinatorics · Mathematics 2017-02-28 Reinhard Diestel

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