Lipschitz geometry of surface germs in ${\mathbb{R}}^4$: metric knots

Lev Birbrair, Michael Brandenbursky, Andrei Gabrielov

A link at the origin of an isolated singularity of a two-dimensional semialgebraic surface in ${\mathbb{R}}^4$ is a topological knot (or link) in $S^3$. We study the connection betwe…