Characterizing Polytopes Contained in the $0/1$-Cube with Bounded Chvátal-Gomory Rank
نویسندگان
چکیده
Let S ⊆ {0, 1} and R be any polytope contained in [0, 1] with R ∩ {0, 1} = S. We prove that R has bounded Chvátal-Gomory rank (CG-rank) provided that S has bounded pitch and bounded gap, where the pitch is the minimum integer p such that all p-dimensional faces of the 0/1-cube have a nonempty intersection with S, and the gap is a measure of the size of the facet coefficients of conv(S). Let H [S̄] denote the subgraph of the n-cube induced by the vertices not in S. We prove that if H [S̄] does not contain a subdivision of a large complete graph, then both the pitch and the gap are bounded. By our main result, this implies that the CG-rank of R is bounded as a function of the treewidth of H [S̄]. We also prove that if S has pitch 3, then the CG-rank of R is always bounded. Both results generalize a recent theorem of Cornuéjols and Lee [8], who proved that the CG-rank is always bounded if the treewidth of H [S̄] is at most 2. Finally, we complement these results by proving that 0/1-polytopes P = conv(S) in R admit extended formulations whose size is bounded in terms of the pitch and the depth D of any circuit deciding membership in S. Our bound is polynomial in n whenever the pitch is constant and D is logarithmic in n.
منابع مشابه
Lower Bounds for Chvátal-gomory Style Operators
Valid inequalities or cutting planes for (mixed-) integer programming problems are an essential theoretical tool for studying combinatorial properties of polyhedra. They are also of utmost importance for solving optimization problems in practice; in fact any modern solver relies on several families of cutting planes. The Chvátal-Gomory procedure, one such approach, has a peculiarity that differ...
متن کاملA family of polytopes in the 0/1-cube with Gomory-Chvátal rank at least ((1+1/6)n - 4)
We provide a family of polytopes P ⊆ [0, 1] whose Gomory-Chvátal rank is at least ((1 + 1/6)n− 4).
متن کاملInteger-empty polytopes in the 0/1-cube with maximal Gomory-Chvátal rank
We provide a complete characterization of all polytopes P ⊆ [0,1]n with empty integer hull whose Gomory-Chvátal rank is n (and, therefore, maximal). In particular, we show that the first GomoryChvátal closure of all these polytopes is identical.
متن کاملLower bounds for the Chvátal-Gomory rank in the 0/1 cube
We revisit the method of Chvátal, Cook, and Hartmann to establish lower bounds on the Chvátal-Gomory rank and develop a simpler method. We provide new families of polytopes in the 0/1 cube with high rank and we describe a deterministic family achieving a rank of at least (1+ 1/e)n− 1> n. Finally, we show how integrality gaps lead to lower bounds.
متن کاملGomory-Chvátal Cutting Planes and the Elementary Closure of Polyhedra
The elementary closure P ′ of a polyhedron P is the intersection of P with all its GomoryChvátal cutting planes. P ′ is a rational polyhedron provided that P is rational. The Chvátal-Gomory procedure is the iterative application of the elementary closure operation to P . The Chvátal rank is the minimal number of iterations needed to obtain PI . It is always finite, but already in R2 one can con...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- CoRR
دوره abs/1611.06593 شماره
صفحات -
تاریخ انتشار 2016