56 citations · 277 across the 50 of their papers we have counts for
4 papers · 1 filter
Cobordisms to weakly splittable links
Stefan Friedl, Mark Powell
We show that if a link L with non-zero Alexander polynomial admits a locally flat cobordism to a `weakly m-split link', then the cobordism must have genus at least (m-1)/2. This ge…
A Second Order Algebraic Knot Concordance Group
Mark Powell
We define an algebraic group comprising symmetric chain complexes which captures the first two stages of the Cochran-Orr-Teichner solvable filtration of the knot concordance group…
Cosmetic crossings and Seifert matrices
Cheryl Balm, Stefan Friedl, Efstratia Kalfagianni +1
We study cosmetic crossings in knots of genus one and obtain obstructions to such crossings in terms of knot invariants determined by Seifert matrices. In particular, we prove that…
Links Not Concordant to the Hopf Link
Stefan Friedl, Mark Powell
We give new Casson-Gordon style obstructions for a two-component link to be topologically concordant to the Hopf link.