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Packing Trees with Constraints on the Leaf Degree

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Abstract

If m is a positive integer then we call a tree on at least 2 vertices an m-tree if no vertex is adjacent to more than m leaves. Kaneko proved that a connected, undirected graph G = (V, E) has a spanning m-tree if and only if for every \(X \subseteq V\) the number of isolated vertices of G − X is at most \(m|X|+{\rm max}\{0,|X| - 1\}\)—unless we have the exceptional case of \(G \simeq K_3\) and m = 1. As an attempt to integrate this result into the theory of graph packings, in this paper we consider the problem of packing a graph with m-trees. We use an approach different from that of Kaneko, and we deduce Gallai–Edmonds and Berge–Tutte type theorems and a matroidal result for the m-tree packing problem.

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References

  1. Cornuéjols, G., Hartvigsen, D.: An extension of matching theory. J. Combin. Theory Ser. B 40, 285–296 (1986)

    Google Scholar 

  2. Cornuéjols, G., Hartvigsen, D., Pulleyblank, W.: Packing subgraphs in a graph. Oper. Res. Letter 1, 139–143 (1981/82)

    Google Scholar 

  3. Edmonds, J.: Paths, trees, and flowers. Canadian J. of Math. 17, 449–467 (1965)

    Google Scholar 

  4. Gallai, T.: Kritische Graphen II. A Magyar Tud. Akad. – Mat. Kut. Int. Közl. 8, 135–139 (1963)

  5. Gallai, T.: Maximale Systeme unabhängiger Kanten. A Magyar Tud. Akad. – Mat. Kut. Int. Közl. 9, 401–413 (1964)

  6. Hartvigsen, D., Hell, P., Szabó, J.: The k-piece packing problem. J. Graph Theory 52, 267–293 (2006)

    Google Scholar 

  7. Kaneko, A.: Spanning trees with constraints on the leaf degree. Discrete Appl. Math. 115, 73–76 (2001)

    Google Scholar 

  8. Kaneko A.: A necessary and sufficient condition for the existence of a path factor every component of which is a path of length at least two. J. Combin. Theory Ser. B 88, 195–218 (2003)

    Google Scholar 

  9. Lovász L.: A generalization of Kőnig’s theorem. Acta Math. Acad. Sci. Hungar. 21, 443–446 (1970)

    Google Scholar 

  10. Lovász L.: A note on factor-critical graphs. Studia Sci. Math. Hungar. 7, 279–280 (1972)

    Google Scholar 

  11. Schrijver A.: Combinatorial optimization. Polyhedra and efficiency. Algorithms and Combinatorics 24, Springer-Verlag, Berlin, 2003

  12. Szabó J.: Graph packings and the degree prescribed factor problem. PhD thesis, Eötvös University, Budapest, 2006. (www.cs.elte.hu/~jacint)

  13. Tutte, W.T.: The factors of graphs. Canadian J. Math. 4, 314–328, (1952)

    Google Scholar 

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Correspondence to Jácint Szabó.

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Jácint Szabó: Research is supported by OTKA grants K60802, TS049788 and by European MCRTN Adonet, Contract Grant No.504438.

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Szabó, J. Packing Trees with Constraints on the Leaf Degree. Graphs and Combinatorics 24, 485–494 (2008). https://doi.org/10.1007/s00373-008-0804-x

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