par Pashkovich, Kanstantsin
Référence Mathematics of operations research, 39, 4, page (1330-1339)
Publication Publié, 2014-11
Article révisé par les pairs
Résumé : It is well known that the permutahedron Πn has 2n - 2 facets. The Birkhoff polytope provides a symmetric extended formulation of Πn of size Θ(n2). Recently, Goemans described a non-symmetric extended formulation of Πn of size Θ(n log n). In this paper, we prove that Ω(n2) is a lower bound for the size of symmetric extended formulations of Πn. Moreover, we prove that the cardinality indicating polytope has the same tight lower bounds for the sizes of symmetric and nonsymmetric extended formulations as the permutahedron.