Knot Diagrams of Treewidth Two

Publication date

2020-10-16

Authors

Bodlaender, HansORCID 0000-0002-9297-3330ISNI 0000000081342475
Burton, Benjamin
Fomin, Fedor V.
Grigoriev, Alexander

Editors

Adler, Isolde
Müller, Haiko

Advisors

Supervisors

Document Type

Part of book
Open Access logo

License

taverne

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.

Keywords

Graph algorithms, Knot diagrams, Knot theory, Series parallel graphs, Treewidth, Taverne, Theoretical Computer Science, General Computer Science

Citation

Bodlaender, H L, Burton, B, Fomin, F V & Grigoriev, A 2020, Knot Diagrams of Treewidth Two. in I Adler & H Müller (eds), Graph-Theoretic Concepts in Computer Science : 46th International Workshop, WG 2020, Leeds, UK, June 24–26, 2020, Revised Selected Papers. 1 edn, Lecture Notes in Computer Science, vol. 12301 , Theoretical Computer Science and General Issues book sub series, Springer, Cham, pp. 80-91, 46th International Workshop on Graph-Theoretic Concepts in Computer Science, WG 2020, Leeds, United Kingdom, 24/06/20. https://doi.org/10.1007/978-3-030-60440-0_7, conference