In this paper we study lift-and-project polyhedral operators defined by Lovász and Schrijver and Balas, Ceria and Cornuéjols on the clique relaxation of the stable set polytope of webs. We compute the disjunctive rank of ...

We study Lovász and Schrijver's hierarchy of relaxations based on positive semidefiniteness constraints derived from the fractional stable set polytope. We show that there are graphs G for which a single application of the ...

The aim of this paper is to study the Lovász-Schrijver PSD operator N+ applied to the edge relaxation of the stable set polytope of a graph. We are particularly interested in the problem of characterizing graphs for which ...

A connected graph G is called t-perfect if its stable set polytope is determined by the non-negativity, edge and odd-cycle inequalities. More- over, G is called strongly t-perfect if this system is totally dual inte- gral. ...

Given a graph G = (V, E), a family of nonempty vertex-subsets S ⊆ 2 V , and a weight w : S → R+, the maximum stable set problem with weights on vertex-subsets consists in finding a stable set I of G maximizing the sum of ...

Clique-node and closed neighborhood matrices of circular interval graphs are circular matrices. The stable set polytope and the dominating set polytope on these graphs are therefore closely related to the set packing ...

We study the Lovász–Schrijver lift-and-project operator (LS +) based on the cone of symmetric, positive semidefinite matrices, applied to the fractional stable set polytope of graphs. The problem of obtaining a combinatorial ...

We describe the adjacency of vertices of the (unbounded version of the) set covering polyhedron, in a similar way to the description given by Chvátal for the stable set polytope. We find a sufficient condition for adjacency, ...

This work presents approaches for the exact solution of the minimum spanning tree problem under conflict constraints. Given a graph G(V,E) and a set C E x E of conflicting edge pairs, the problem consists of finding a ...