|  Résume | Most closed 3-manifolds support a hyperbolic metric, uniquely 
determined by their topology. Extracting geometric information from a 
combinatorial presentation of the manifold is an intriguing and usually 
hard problem. In this talk, instead of focusing on a single 3-manifold, we 
study the growth rate of geometric invariants in families of 3-manifolds 
that share a common combinatorial description. Specifically, we will work 
with families of random 3-manifolds as introduced by Dunfield and 
Thurston. We will introduce an explicit negatively curved metric on them 
and use it to compute volume and spectral gap of the underlying hyperbolic 
structures. Joint work with Ursula Hamenstädt.  |