Mathematics – Geometric Topology
Scientific paper
2012-03-14
Mathematics
Geometric Topology
43 pages
Scientific paper
Given a knot K we introduce a new invariant coming from the Blanchfield pairing and we show that it gives a lower bound on the unknotting number of K. This lower bound subsumes the lower bounds given by the Levine-Tristram signatures, by the Nakanishi index and it also subsumes the Lickorish obstruction to the unknotting number being equal to one. Our approach in particular allows us to show for 25 knots with up to 12 crossings that their unknotting number is at least three, most of which are very difficult to treat otherwise.
Borodzik Maciej
Friedl Stefan
No associations
LandOfFree
The unknotting number and classical invariants I does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The unknotting number and classical invariants I, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The unknotting number and classical invariants I will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-29985