#### Volume 17, issue 5 (2017)

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 The Journal About the Journal Subscriptions Editorial Board Editorial Interests Editorial Procedure Submission Guidelines Submission Page Author Index To Appear ISSN (electronic): 1472-2739 ISSN (print): 1472-2747
HOMFLY-PT homology for general link diagrams and braidlike isotopy

### Michael Abel

Algebraic & Geometric Topology 17 (2017) 3021–3056
##### Abstract

Khovanov and Rozansky’s categorification of the homfly-pt polynomial is invariant under braidlike isotopies for any general link diagram and Markov moves for braid closures. To define homfly-pt homology, they required a link to be presented as a braid closure, because they did not prove invariance under the other oriented Reidemeister moves. In this text we prove that the Reidemeister IIb move fails in homfly-pt homology by using virtual crossing filtrations of the author and Rozansky. The decategorification of homfly-pt homology for general link diagrams gives a deformed version of the homfly-pt polynomial, ${P}^{b}\left(D\right)$, which can be used to detect nonbraidlike isotopies. Finally, we will use ${P}^{b}\left(D\right)$ to prove that homfly-pt homology is not an invariant of virtual links, even when virtual links are presented as virtual braid closures.

##### Keywords
braidlike isotopy, Khovanov–Rozansky homology, virtual links
##### Mathematical Subject Classification 2010
Primary: 57M25, 57M27
##### Publication
Revised: 7 March 2017
Accepted: 27 March 2017
Published: 19 September 2017
##### Authors
 Michael Abel Department of Mathematics Duke University Durham, NC United States http://services.math.duke.edu/~maabel/