Alternating links have representativity 2
arXiv:1703.03393 · doi:10.2140/agt.2018.18.3339
Abstract
We prove that if is a non-trivial alternating link embedded (without crossings) in a closed surface , then has a compressing disk whose boundary intersects in no more than two points. Moreover, whenever the surface is incompressible and -incompressible in the link exterior, it can be isotoped to have a standard tube at some crossing of any reduced alternating diagram.
17 pages, 14 figures