Computation of Gordian distances and H2-Gordian distances of knots
One of the most complicated problems in Knot theory is to compute unknotting number. Hass, Lagarias and Pippenger proved that the unknotting problem is NP hard. In this paper we discuss the question of computing unknotting number from minimal knot diagrams, Bernhard-Jablan Conjecture, unknown knot d...
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Veröffentlicht in: | Yugoslav Journal of Operations Research 2015, Vol.25 (1), p.133-152 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | One of the most complicated problems in Knot theory is to compute unknotting
number. Hass, Lagarias and Pippenger proved that the unknotting problem is NP
hard. In this paper we discuss the question of computing unknotting number
from minimal knot diagrams, Bernhard-Jablan Conjecture, unknown knot
distances between non-rational knots, and searching for minimal distances by
using a graph with weighted edges, which represents knot distances. Since
topoizomerazes are enzymes involved in changing crossing of DNA, knot
distances can be used to study topoizomerazes actions. In the existing tables
of knot smoothing, knots with smoothing number 1 are computed by Abe and
Kanenobu [27] for knots with at most n = 9 crossings, and smoothing knot
distances are computed by Kanenobu [26] for knots with at most n = 7
crossings. We compute some undecided knot distances 1 from these papers, and
extend the computations by computing knots with smoothing number one with at
most n = 11 crossings and smoothing knot distances of knots with at most n =
9 crossings. All computations are done in LinKnot, based on Conway notation
and non-minimal representations of knots. |
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ISSN: | 0354-0243 1820-743X 2334-6043 |
DOI: | 10.2298/YJOR131210044Z |