Abstract:
A family of neighbourly polytopes in R2d with N=2d+4 vertices is constructed. All polytopes in the family have a planar Gale diagram of a special type, namely, with exactly d+3 black points in convex position. These Gale diagrams are parametrized by 3-trees (trees with a certain additional structure). For all polytopes in the family, the number of faces of dimension m containing a given vertex A depends only on d and m.
Bibliography: 7 titles.
Keywords:
combinatorics of polytopes, combinatorics of a set of points, neighbourly polytopes, Gale diagrams.