A classification of centrally-symmetric and cyclic 12-vertex triangulations of S2×S2 Original Research Article

In this paper our main result states that there exist exactly three combinatorially distinct centrally symmetric 12-vertex-triangulations of the product of two 2-spheres with a cyclic symmetry. We also compute the automorphism groups of the triangulations. These instances suggest that there is a triangulation of S2×S2 with 11 vertices — the minimum number of vertices required.