Knot Diagrams of Treewidth Two

Hans L. Bodlaender*, Benjamin Burton, Fedor V. Fomin, Alexander Grigoriev

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

Abstract

In this paper, we study knot diagrams for which the underlying graph has treewidth two. We give a linear time algorithm for the following problem: given a knot diagram of treewidth two, does it represent the trivial knot? We also show that for a link diagram of treewidth two we can test in linear time if it represents the unlink. From the algorithm, it follows that a diagram of the trivial knot of treewidth 2 can always be reduced to the trivial diagram with at most n untwist and unpoke Reidemeister moves.

Original languageEnglish
Title of host publicationGraph-Theoretic Concepts in Computer Science
Subtitle of host publication46th International Workshop, WG 2020, Leeds, UK, June 24–26, 2020, Revised Selected Papers
EditorsIsolde Adler, Haiko Müller
Place of PublicationCham
PublisherSpringer
Pages80-91
Number of pages12
Edition1
ISBN (Electronic)978-3-030-60440-0
ISBN (Print)978-3-030-60439-4
DOIs
Publication statusPublished - 16 Oct 2020
Event46th International Workshop on Graph-Theoretic Concepts in Computer Science, WG 2020 - Leeds, United Kingdom
Duration: 24 Jun 202026 Jun 2020

Publication series

NameLecture Notes in Computer Science
PublisherSpringer
Volume12301
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349
NameTheoretical Computer Science and General Issues book sub series
PublisherSpringer
ISSN (Print)2512-2010
ISSN (Electronic)2512-2029

Conference

Conference46th International Workshop on Graph-Theoretic Concepts in Computer Science, WG 2020
Country/TerritoryUnited Kingdom
CityLeeds
Period24/06/2026/06/20

Funding

A large part of this research was done during the workshop Fixed Parameter Computational Geometry at the Lorentz Center in Leiden. The research of the first author was partially supported by the Networks project, supported by the Netherlands Organization for Scientific Research N.W.O. The second author was supported by the Australian Research Council under the Discovery Projects scheme (DP150104108). The third author was supported by the Research Council of Norway via the project “MULTIVAL”.

Keywords

  • Graph algorithms
  • Knot diagrams
  • Knot theory
  • Series parallel graphs
  • Treewidth

Fingerprint

Dive into the research topics of 'Knot Diagrams of Treewidth Two'. Together they form a unique fingerprint.

Cite this