The embedding space of a Hopf link

Abstract

We study the unparametrised smooth embedding space of a Hopf link in $\mathbb{R}^3$, and prove that it is homotopy equivalent to the closed 3-manifold $S^3/\mathbb{Q}_8$. As an intermediate step in the proof, we show that the inclusion of the subspace of round embeddings is a homotopy equivalence. We provide analogous results for the unparametrised smooth embedding space of a Hopf link in $S^3$, which we show is homotopy equivalent to $\mathbb{R} P^2\times \mathbb{R} P^2$.