The poset of rational cones
  We introduce a natural partial order on the set Cones(d) of rational cones in R^d. The poset NPol(d-1) of normal polytopes in R^{d-1} embeds into Cones(d) via the homogenization map. The order in Cones(d) is conjecturally the inclusion order. We prove this for d=3 and show a stronger version of the connectivity of Cones(d) for all d. Topological aspects of the conjecture are also discussed. 
Joseph Gubeladze and Mateusz Micha{\l}ek
math.CO math.NT