Abstract
We study quasi-morphisms on the groups Pn of pure braids on n strings and on the group D of compactly supported area-preserving diffeomorphisms of an open two-dimensional disk. We show that it is possible to build quasi-morphisms on Pn by using knot invariants which satisfy some special properties. In particular, we study quasi-morphisms which come from knot Floer homology and Khovanov-type homology. We then discuss possible variations of the GambaudoGhys construction, using the above quasi-morphisms on Pn to build quasi-morphisms on the group D of diffeomorphisms of a 2-disk.
Original language | American English |
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Pages (from-to) | 1397-1417 |
Number of pages | 21 |
Journal | Journal of Knot Theory and its Ramifications |
Volume | 20 |
Issue number | 10 |
DOIs | |
State | Published - 1 Oct 2011 |
Externally published | Yes |
Keywords
- Quasi-morphisms
- area-preserving diffeomorphisms
- braid groups
- knot concordance invariants
All Science Journal Classification (ASJC) codes
- Algebra and Number Theory