Profinite rigidity witnessed by Dehn fillings of cusped hyperbolic 3-manifolds
Xiaoyu Xu
TL;DR
This work advances profinite rigidity for cusped finite-volume hyperbolic 3-manifolds by proving that any profinite isomorphism induces a correspondence between Dehn fillings via peripheral $\widehat{\mathbb{Z}}^{\times}$-regularity. The authors develop a robust framework to detect exceptional Dehn fillings from finite quotients, linking prime decomposition, toroidality, and Klein bottles to profinite data. They establish explicit profinite rigidity for a variety of manifolds, including the Whitehead link complement, Whitehead sister link, the $\tfrac{3}{10}$-two-bridge link, several twist and Eudave-Muñoz knots, the Berge manifold, and related surgeries, often via characterising slopes. The results provide both new rigid examples and refined criteria for knot-complement rigidity, suggesting that profinite information may strongly constrain hyperbolic 3-manifolds and supporting the broader conjecture that profinite data uniquely determines a cusped hyperbolic 3-manifold within the orientable category.
Abstract
Any profinite isomorphism between two cusped finite-volume hyperbolic 3-manifolds carries profinite isomorphisms between their Dehn fillings. With this observation, we prove that some cusped finite-volume hyperbolic 3-manifolds are profinitely rigid among all compact, orientable 3-manifolds, through detecting their exceptional Dehn fillings. In addition, we improved a criteria for profinite rigidity of a hyperbolic knot complement or a hyperbolic-type satellite knot complement among compact, orientable 3-manifolds, through examining its characterising slopes. We obtain the following profinitely rigid examples: the complement of the Whitehead link, Whitehead sister link, $\frac{3}{10}$ two-bridge link; specific surgeries on one component of these links; the complement of (full) twist knots $\mathcal{K}_n$, Eudave-Muñoz knots $K(3,1,n,0)$, Pretzel knots $P(-3,3,2n+1)$, $5_2$ knot; the Berge manifold, and many more.
