Inequalities for cd-Indices of Joins and Products of Polytopes
نویسندگان
چکیده
The cd-index is a polynomial which encodes the flag f-vector of a convex polytope. For poly-topes U and V , we determine explicit recurrences for computing the cd-index of the free join U ∨ V and the cd-index of the Cartesian product U × V. As an application of these recurrences, we prove the inequality Ψ(U ∨ (V × W)) ≤ Ψ((U ∨ V) × W) involving the cd-indices of three polytopes.
منابع مشابه
Products of polytopes and inequalities
The cd-index is a polynomial which encodes the ag f-vector of a convex polytope. We determine explicit recurrences for computing the cd-index of the free join U _ V of two polytopes U and V and the cd-index of the Cartesian product U V. As an application of these recurrences, we prove the inequality (U _ (V W)) ((U _ V) W) involving the cd-indices of three polytopes.
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عنوان ژورنال:
- Combinatorica
دوره 23 شماره
صفحات -
تاریخ انتشار 2003