Abstract
Suppose that k is a non-negative integer and a bipartite multigraph G is the union of
matchings \(M_1,\dots ,M_N\), each of size n. We show that G has a rainbow matching of size \(n-k\), i.e. a matching of size \(n-k\) with all edges coming from different \(M_i\)’s. Several choices of the parameter k relate to known results and conjectures.
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References
R. Aharoni, personal communication
R. Aharoni, E. Berger, Rainbow matchings in \(r\)-partite \(r\)-graphs. Electron. J. Combin. 16(1), R119 (2009)
R. Aharoni, P. Charbit, D. Howard, On a generalization of the Ryser–Brualdi–Stein conjecture. J. Graph Theory 78(2), 143–156 (2015)
R.A. Brualdi, H.J. Ryser, Combinatorial Matrix Theory (Cambridge University Press, Cambridge, UK, 1991)
A.E. Brouwer, A.J. de Vries, R.M.A. Wieringa, A lower bound for the length of partial transversals in a Latin square. Nieuw Arch. Wisk. 24(3), 330–332 (1978)
D. Clemens, J. Ehrenmüller, An improved bound on the sizes of matchings guaranteeing a rainbow matching, arXiv:1503.00438
A.A. Drisko, Transversals in row-latin rectangles. J. Combin. Theory Ser. A 84, 181–195 (1998)
P. Hatami, P.W. Shor, A lower bound for the length of a partial transversal in a Latin square. J. Combin. Theory Ser. A 115, 1103–1113 (2008)
D. Kotlar, R. Ziv, Large matchings in bipartite graphs have a rainbow matching. Eur. J. Combin. 38, 97–101 (2014)
H.J. Ryser, Neuere probleme der kombinatorik (Vorträge über Kombinatorik Oberwolfach, Mathematisches Forschungsinstitut Oberwolfach, July 1967)
P.W. Shor, A lower bound for the length of a partial transversal in a Latin square. J. Combin. Theory Ser. A 33, 1–8 (1982)
S.K. Stein, Transversals of latin squares and their generalizations. Pacific J. Math. 59, 567–575 (1975)
D.E. Woolbright, An \(n\times n\) Latin square has a transversal with at least \(n-\sqrt{n}\) distinct symbols. J. Combin. Theory Ser. A 24, 235–237 (1978)
Acknowledgements
A. Gyárfás: Research was supported in part by OTKA K104343. G. N. Sárközy: Research was supported in part by OTKA K104343.
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Barát, J., Gyárfás, A. & Sárközy, G.N. Rainbow matchings in bipartite multigraphs. Period Math Hung 74, 108–111 (2017). https://doi.org/10.1007/s10998-016-0172-x
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DOI: https://doi.org/10.1007/s10998-016-0172-x