Skip to main content
Added gt.geometric-topology tag.
Link
HJRW
  • 25k
  • 3
  • 68
  • 144
Source Link

How to increase the injectivity radius function of a hyperbolic 3 manifold of finite volume?

Let $N$ be an oriented hyperbolic 3-manifold of finite volume and let $\Delta \subset N$ be a smooth connected compact subdomain such that the restriction of the injectivity radius function of $N$ to $\Delta$ is larger than some $\varepsilon > 0$ ($\Delta$ could be a thick part of $N$). Is there some finite cover $\Pi\colon \widehat{N} \to N$ such that the injectivity radius function of $\widehat{N}$ restricted to any component of $\Pi^{-1}(\Delta)$ is greater than $\varepsilon + 1$?