Abstract
A simple 2-matching in an edge-weighted graph is a subgraph all of whose nodes have degree 0, 1 or 2. We consider the problem of finding a maximum weight simple 2-matching that contains no triangles, which is closely related to a class of relaxations of the traveling salesman problem (TSP). Our main results are, for graphs with maximum degree 3, a complete description of the convex hull of incidence vectors of triangle-free simple 2-matchings and a strongly polynomial time algorithm for the above problem. Our system requires the use of a type of comb inequality (introduced by Grötschel and Padberg for the TSP polytope) that has {0,1,2}-coefficients and hence is more general than the well-known blossom inequality used in Edmonds’ characterization of the simple 2-matching polytope.
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An extended abstract of this paper [“Triangle-free simple 2-matchings in subcubic graphs (extended abstract)”] appeared in Integer Programming and Combinatorial Optimization, 12th International IPCO Conference, Ithaca, NY, June 2007, Eds.: M. Fischetti and D.P. Williamson, Springer Verlag, Lecture Notes in Computer Science 4513, Berlin (2007) 43–52.
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Hartvigsen, D., Li, Y. Polyhedron of triangle-free simple 2-matchings in subcubic graphs. Math. Program. 138, 43–82 (2013). https://doi.org/10.1007/s10107-012-0516-0
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DOI: https://doi.org/10.1007/s10107-012-0516-0