English

Characterization of positive links and the $s$-invariant for links

Geometric Topology 2017-10-27 v6

Abstract

We characterize positive links in terms of strong quasipositivity, homogeneity and the value of Rasmussen, Beliakova and Wehrli's ss-invariant. We also study almost positive links, in particular, determine the ss-invariants of almost positive links. This result suggests that all almost positive links might be strongly quasipositive. On the other hand, it implies that almost positive links are never homogeneous links.

Keywords

Cite

@article{arxiv.1405.4061,
  title  = {Characterization of positive links and the $s$-invariant for links},
  author = {Tetsuya Abe and Keiji Tagami},
  journal= {arXiv preprint arXiv:1405.4061},
  year   = {2017}
}

Comments

18 pages, 10 figures, v5:the statements of Corollary 1.7 and Corollary 7.4 were corrected, Question 10.5 and two references were added, v6:this is the published version, survey parts are deleted