English
Related papers

Related papers: Trees of tangles in infinite separation systems

200 papers

We introduce and study the Separation Problem for infinite graphs, which involves determining whether a connected graph splits into at least two infinite connected components after the removal of a given finite set of edges. We prove that…

Logic · Mathematics 2026-02-11 Nicanor Carrasco-Vargas , Valentino Delle Rose , Cristóbal Rojas

We extend Milnor's mu-invariants of link homotopy to ordered (classical or virtual) tangles. Simple combinatorial formulas for mu-invariants are given in terms of counting trees in Gauss diagrams. Invariance under Reidemeister moves…

Geometric Topology · Mathematics 2015-05-20 Olga Kravchenko , Michael Polyak

A network-theoretic approach for determining the complexity of a graph is proposed. This approach is based on the relationship between the linear algebra (theory of determinants) and the graph theory. In this paper we contribute a new…

Discrete Mathematics · Computer Science 2018-12-04 E. M. Badr , B. Mohamed

We generalize the concept of token graphs to obtain supertoken graphs. In the latter case, there can be more than one token in a vertex. We formally define supertoken graphs and establish their basic properties. Moreover, we provide some…

Combinatorics · Mathematics 2026-04-08 Mónica A. Reyes , Cristina Dalfó , Miquel Àngel Fiol

We state and prove some counting formulas relating to cliques in the distant graphs of projective lines over finite rings. As a preliminary to this, we prove a decomposition theorem for the graphs in terms of the direct-product…

Combinatorics · Mathematics 2016-12-26 Tim Silverman

We consider two notions describing how one finite graph may be larger than another. Using them, we prove several theorems for such pairs that compare the number of spanning trees, the return probabilities of random walks, and the number of…

Combinatorics · Mathematics 2018-09-10 Russell Lyons

In finite graphs, finite-order tangles offer an abstract description of highly connected substructures. In infinite graphs, infinite-order tangles compactify the graphs in the same way the ends compactify connected locally finite graphs.…

Combinatorics · Mathematics 2019-08-28 Jan Kurkofka

We introduce a new graph invariant of finite groups that provides a complete characterization of the splitting types of unramified prime ideals in normal number field extensions entirely in terms of the Galois group. In particular, each…

Number Theory · Mathematics 2007-05-23 Fusun Akman

We deduce from a theorem of Dvorak--Norin that the separation and treewidth profiles of graphs are asymptotically equivalent, resolving a question of Huang--Hume--Kelly--Lam. As an application, we calculate the separation profiles of Cayley…

Combinatorics · Mathematics 2026-04-28 David Hume

We give a short proof that every finite graph (or matroid) has a tree-decomposition that displays all maximal tangles. This theorem for graphs is a central result of the graph minors project of Robertson and Seymour and the extension to…

Combinatorics · Mathematics 2016-06-01 Johannes Carmesin

Every end of an infinite graph $ G $ defines a tangle of infinite order in $ G $. These tangles indicate a highly cohesive substructure in the graph if and only if they are closed in some natural topology. We characterize, for every finite…

Combinatorics · Mathematics 2025-05-16 Jay Lilian Kneip

We establish splitter theorems for graph immersions for two families of graphs, $k$-edge-connected graphs, with $k$ even, and 3-edge-connected, internally 4-edge-connected graphs. As a corollary, we prove that every $3$-edge-connected,…

Combinatorics · Mathematics 2025-07-09 Matt DeVos , Mahdieh Malekian

We investigate the validity of the Phragm\`en-Lindel\"of principle for a class of elliptic equations with a potential, posed on infinite graphs. Consequently, we get uniqueness, in the class of solutions satisfying a suitable growth…

Analysis of PDEs · Mathematics 2024-06-26 Stefano Biagi , Fabio Punzo

We compute explicitly (modulo solutions of certain algebraic equations) the spectra of infinite graphs obtained by attaching one or several infinite paths to some vertices of certain finite graphs. The main result concerns a canonical form…

Combinatorics · Mathematics 2015-03-18 Leonid Golinskii

This paper is a short introduction to the theory of tangles, both in graphs and general connectivity systems. An emphasis is put on the correspondence between tangles of order k and k-connected components. In particular, we prove that there…

Discrete Mathematics · Computer Science 2016-02-16 Martin Grohe

In this paper, we define a class of auxiliary graphs associated with simple undirected graphs. This class of auxiliary graphs is based on the set of spanning trees of the original graph and the edges constituting those spanning trees. A…

Combinatorics · Mathematics 2019-02-26 Abhishek Garg , Mahipal Jadeja , Rahul Muthu

We derive representation theorems for exchangeable distributions on finite and infinite graphs using elementary arguments based on geometric and graph-theoretic concepts. Our results elucidate some of the key differences, and their…

Statistics Theory · Mathematics 2018-09-18 Steffen L. Lauritzen , Alessandro Rinaldo , Kayvan Sadeghi

In this paper we discuss reconstruction problems for graphs. We develop some new ideas like isomorphic extension of isomorphic graphs, partitioning of vertex sets into sets of equivalent points, subdeck property, etc. and develop an…

General Mathematics · Mathematics 2011-10-21 Dhananjay P. Mehendale

In this series, we introduce and investigate the concept of connectoids, which captures the connectivity structure of various discrete objects such as undirected graphs, directed graphs, bidirected graphs, hypergraphs and finitary matroids.…

Combinatorics · Mathematics 2026-05-21 Nathan Bowler , Florian Reich

We prove that any quasirandom graph with $n$ vertices and $rn$ edges can be decomposed into $n$ copies of any fixed tree with $r$ edges. The case of decomposing a complete graph establishes a conjecture of Ringel from 1963.

Combinatorics · Mathematics 2020-04-22 Peter Keevash , Katherine Staden