Classification of Hamiltonian torus actions with two dimensional quotients

Abstract

We construct all possible Hamiltonian torus actions for which all the non-empty reduced spaces are two dimensional (and not single points) and the manifold is connected and compact, or, more generally, the moment map is proper as a map to a convex set. This construction completes the classification of tall complexity one spaces.

46 pages, 2 figures. v2: added a reference