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Among other results, it is shown that 3-trees are $\Delta$-edge-choosable and that graphs of tree-width 3 and maximum degree at least 7 are $\Delta$-edge-choosable.

Combinatorics · Mathematics 2015-04-10 Richard Lang

For all integers $k\geq 3$, we give an $O(n^4)$ time algorithm for the problem whose instance is a graph $G$ of girth at least $k$ together with $k$ vertices and whose question is "Does $G$ contains an induced subgraph containing the $k$…

Discrete Mathematics · Computer Science 2013-09-06 Wei Liu , Nicolas Trotignon

An independent set in a graph $G$ is a set of pairwise non-adjacent vertices. A tree decomposition of $G$ is a pair $(T, \chi)$ where $T$ is a tree and $\chi : V(T) \rightarrow 2^{V(G)}$ is a function satisfying the following two axioms:…

Combinatorics · Mathematics 2026-05-07 Maria Chudnovsky , Ajaykrishnan E S , Daniel Lokshtanov

Considering the worst-case scenario, junction tree algorithm remains the most general solution for exact MAP inference with polynomial run-time guarantees. Unfortunately, its main tractability assumption requires the treewidth of a…

Discrete Mathematics · Computer Science 2022-02-10 Alexander Bauer , Shinichi Nakajima

Graph pebbling is a network optimization model for satisfying vertex demands with vertex supplies (called pebbles), with partial loss of pebbles in transit. The pebbling number of a demand in a graph is the smallest number for which every…

Combinatorics · Mathematics 2021-12-22 Glenn Hurlbert , Essak Seddiq

The task of finding an extension to a given partial drawing of a graph while adhering to constraints on the representation has been extensively studied in the literature, with well-known results providing efficient algorithms for…

Computational Geometry · Computer Science 2023-02-21 Sujoy Bhore , Robert Ganian , Liana Khazaliya , Fabrizio Montecchiani , Martin Nöllenburg

Partial edge drawing (PED) is a drawing style for non-planar graphs, in which edges are drawn only partially as pairs of opposing stubs on the respective end-vertices. In a PED, by erasing the central parts of edges, all edge crossings and…

Computational Geometry · Computer Science 2019-08-27 Matthias Hummel , Fabian Klute , Soeren Nickel , Martin Nöllenburg

Given a family $\mathcal{H}$ of graphs, we say that a graph $G$ is $\mathcal{H}$-free if no induced subgraph of $G$ is isomorphic to a member of $\mathcal{H}$. Let $S_{t,t,t}$ be the graph obtained from $K_{1,3}$ by subdividing each edge…

Combinatorics · Mathematics 2025-02-10 Maria Chudnovsky , Julien Codsi , Daniel Lokshtanov , Martin Milanič , Varun Sivashankar

We derive a quadratic-time algorithm for the genus distribution of any 3-regular, biconnected series-parallel graph, which we extend to any biconnected series-parallel graph of maximum degree at most 3. Since the biconnected components of…

Discrete Mathematics · Computer Science 2014-07-31 Jonathan L. Gross , Michal Kotrbčík , Timothy Sun

The class of all even-hole-free graphs has unbounded tree-width, as it contains all complete graphs. Recently, a class of (even-hole, $K_4$)-free graphs was constructed, that still has unbounded tree-width [Sintiari and Trotignon, 2019].…

Discrete Mathematics · Computer Science 2023-10-30 Pierre Aboulker , Isolde Adler , Eun Jung Kim , Ni Luh Dewi Sintiari , Nicolas Trotignon

We prove a conjecture of Sintiari and Trotignon that every even-hole-free graph of sufficiently large treewidth contains a four-vertex induced subgraph with at least five edges (that is, either the four-vertex complete graph or the unique…

Combinatorics · Mathematics 2025-10-08 Bogdan Alecu , Maria Chudnovsky , Sepehr Hajebi , Sophie Spirkl

A tree $t$-spanner of a graph $G$ is a spanning tree of $G$ such that the distance between pairs of vertices in the tree is at most $t$ times their distance in $G$. Deciding tree $t$-spanner admissible graphs has been proved to be tractable…

Discrete Mathematics · Computer Science 2018-01-01 Ioannis Papoutsakis

The eternal vertex cover problem is a dynamic variant of the classical vertex cover problem. It is NP-hard to compute the eternal vertex cover number of graphs and known algorithmic results for the problem are very few. This paper presents…

Discrete Mathematics · Computer Science 2020-05-19 Jasine Babu , Veena Prabhakaran , Arko Sharma

We show that Odd Cycle Transversal and Vertex Multiway Cut admit deterministic polynomial kernels when restricted to planar graphs and parameterized by the solution size. This answers a question of Saurabh. On the way to these results, we…

Data Structures and Algorithms · Computer Science 2018-12-13 Bart M. P. Jansen , Marcin Pilipczuk , Erik Jan van Leeuwen

The Burning Number Conjecture, that a graph on $n$ vertices can be burned in at most $\lceil \sqrt{n} \ \rceil$ rounds, has been of central interest for the past several years. Much of the literature toward its resolution focuses on two…

Combinatorics · Mathematics 2021-11-03 Mohamed Omar , Vibha Rohilla

Scott proved in 1997 that for any tree $T$, every graph with bounded clique number which does not contain any subdivision of $T$ as an induced subgraph has bounded chromatic number. Scott also conjectured that the same should hold if $T$ is…

Combinatorics · Mathematics 2022-03-03 Jérémie Chalopin , Louis Esperet , Zhentao Li , Patrice Ossona de Mendez

An added edge to a graph is called an inset edge. Predicting k inset edges which minimize the average distance of a graph is known to be NP-Hard. When k = 1 the complexity of the problem is polynomial. In this paper, we further find the…

Data Structures and Algorithms · Computer Science 2020-08-14 M. H. Khalifeh , A. -H. Esfahanian

In this paper we construct spanning trees in hyperbolic graphs that represent their hyperbolic compactification in a good way: so that the tree has a bounded number of distinct rays to each boundary point. The bound depends only on the…

Combinatorics · Mathematics 2013-01-31 Matthias Hamann

Two kinds of approximation algorithms exist for the k-BALANCED PARTITIONING problem: those that are fast but compute unsatisfying approximation ratios, and those that guarantee high quality ratios but are slow. In this paper we prove that…

Computational Complexity · Computer Science 2019-04-29 Andreas Emil Feldmann

Tree spanners approximate distances within graphs; a subtree of a graph is a tree $t$-spanner of the graph if and only if for every pair of vertices their distance in the subtree is at most $t$ times their distance in the graph. When a…

Discrete Mathematics · Computer Science 2015-05-20 Ioannis Papoutsakis
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