Complément to the Thurston 3D-geometrization picture

Abstract

Geometrization says that “any closed oriented three-manifold which is prime (not a connected sum) carries one of the eight Thurston geometries OR it has incompressible torus walls whose complementary components each carry one of four particular Thurston geometries”. These geometric components have finite volume for the hyperbolic geometries. They also have finite volume for each of the two geometries appearing as Seifert fibrations. The remaining pieces have Euclidean geometries of linear volume growth. Then these vertex geometries are combined topologically to recover the original manifold. This, by cutting off the toroidal ends and then gluing the torus boundaries by affine mappings. The point of this work is to make the affine gluing respect an interpretation of the metric geometry in terms of a new notion of “regional Lie generated geometry”. The vertex regions use four geometries in Lie form combined in the overlap edge regions via affine geometry. The theorem solves, using geometrization, a forty-five-year-old question/approach to the Poincaré conjecture. This was described in a 1976 Princeton Mathematics Department preprint and finally documented by Thurston and the second author (1983).