McMullen problem

The McMullen problem, posed by mathematician Curtis T. McMullen in the late 20th century, pertains to the study of hyperbolic 3-manifolds and their geometric structures. Specifically, it concerns the classification of certain types of 3-manifolds known as "hyperbolic 3-manifolds" and the conditions under which these manifolds can be represented as the complement of a knot in S³ (the 3-sphere).