{ "id": "1611.10330", "version": "v1", "published": "2016-11-30T19:44:22.000Z", "updated": "2016-11-30T19:44:22.000Z", "title": "Linking Numbers in Three-Manifolds", "authors": [ "Patricia Cahn", "Alexandra Kjuchukova" ], "comment": "30 pages, 12 figures", "categories": [ "math.GT" ], "abstract": "We give an explicit algorithm for computing linking numbers between curves in an irregular dihedral $p$-fold branched cover of $S^3$. This work extends a combinatorial algorithm by Perko which computes the linking number between the branch curves in the case $p=3$. Owing to the fact that every closed oriented three-manifold is a dihedral three-fold branched cover of $S^3$, the algorithm given here can be used to compute linking numbers in any three-manifold, provided that the manifold is presented as a dihedral cover of the sphere. The algorithm has been implemented in Python, and we include the code in an Appendix.", "revisions": [ { "version": "v1", "updated": "2016-11-30T19:44:22.000Z" } ], "analyses": { "subjects": [ "57M27", "57M25", "57M12" ], "keywords": [ "three-manifold", "dihedral three-fold branched cover", "work extends", "combinatorial algorithm", "irregular dihedral" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }