Abstract
Dabkowski and Sahi defined an invariant of a link in the 3-sphere, which is preserved under 4-moves. This invariant is a quotient of the fundamental group of the complement of the link. It is generally difficult to distinguish between the Dabkowski-Sahi invariants of given links. In this paper, we give a necessary condition for the existence of an isomorphism between the Dabkowski-Sahi invariant of a link and that of the corresponding trivial link. Using this condition, we provide a practical obstruction to a link to be trivial up to 4-moves.
Original language | English |
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Article number | 46 |
Journal | Geometriae Dedicata |
Volume | 217 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2023 Jun |
Keywords
- 4-move
- Link
- Link-homotopy
- Magnus expansion
- Welded link
ASJC Scopus subject areas
- Geometry and Topology