A Casson-Lin type invariant for links
Geometric Topology
2009-11-23 v3
Abstract
We define an integer valued invariant for two-component links in S^3 by counting projective SU(2) representations of the link group having non-trivial second Stiefel-Whitney class. We show that our invariant is, up to sign, the linking number of the link. Our construction generalizes that of X.-S. Lin who defined a similar invariant for knots in S^3; his invariant equals half the knot signature.
Cite
@article{arxiv.0907.1070,
title = {A Casson-Lin type invariant for links},
author = {Eric Harper and Nikolai Saveliev},
journal= {arXiv preprint arXiv:0907.1070},
year = {2009}
}
Comments
New set of generators for the braid group in Section 2