Abstract
Given a graph G and a positive integer k, define the Gallai—Ramsey number to be the minimum number of vertices n such that any k-edge coloring of Kn contains either a rainbow (all different colored) triangle or a monochromatic copy of G. In this paper, we obtain exact values of the Gallai—Ramsey numbers for the union of two stars in many cases and bounds in other cases. This work represents the first class of disconnected graphs to be considered as the desired monochromatic subgraph.
Similar content being viewed by others
References
Cameron, K., Edmonds, J.: Lambda composition. J. Graph Theory, 26, 9–16 (1997)
Dirac, G. A.: Some theorems on abstract graphs. Proc. London Math. Soc., 2, 69–81 (1952)
Faudree, R. J., Schelp, R. H.: All Ramsey numbers for cycles in graphs. Discrete Math., 8, 313–329 (1974)
Fujita, S., Magnant, C.: Gallai—Ramsey numbers for cycles. Discrete Math., 311, 1247–1254 (2011)
Fujita, S., Magnant, C., Ozeki K.: Rainbow generalizations of Ramsey theory-a dynamic survey. Theo. Appl. Graphs, 0, Iss. 1, Article 1 (2014)
Gallai, T.: Transitiv orientierbare Graphen. Acta Math. Acad. Sci. Hungar, 18, 25–66 (1967)
Grossman, J. W.: The Ramsey numbers of the union of two stars. Utilitas Math., 16, 271–279 (1979)
Gyárfás, A., Sárközy, G., Sebő, A., et al.: Ramsey-type results for gallai colorings. J. Graph Theory, 64, 233–243 (2010)
Gyaárfás, A., Simonyi, G.: Edge colorings of complete graphs without tricolored triangles. J. Graph Theory, 46, 211–216 (2004)
Hall, M., Magnant, C., Ozeki, K., et al.: Improved upper bounds for Gallai—Ramsey numbers of paths and cycles. J. Graph Theory, 75, 59–74 (2014)
Hendry, G. R. T.: Extending cycles in graphs. Discrete Math., 85, 59–72 (1990)
Károlyi, G., Rosta, V.: Generalized and geometric Ramsey numbers for cycles. Theoret. Comput. Sci., 263, 87–98 (2001)
Magnant, C., Nowbandegani, P. S.: Topics in Gallai—Ramsey Theory, Springer Briefs in Mathematics, Springer, Switzerland, 2020
Radziszowski, S. P.: Small Ramsey numbers. Electron. J. Combin., 1, 1–30 (1994)
Rosta, V.: On a Ramsey-type problem of J. A. Bondy and P. Erdős. I, II. J. Combin. Theory, Ser. B, 263, 105–120 (1973)
Wang, Z., Mao, Y., Magnant, C., et al.: Gallai—Ramsey numbers of odd cycles. arXiv:1808.09245v2
Wu, H. B., Magnant, C., Nowbandegani, P.S., et al.: All partitions have small parts-Gallai—Ramsey numbers of bipartite graphs. Discrete Appl. Math., 254, 196–203 (2019)
Acknowledgements
We would like to thank the anonymous referees for a number of helpful comments and suggestions.
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by the National Science Foundation of China (Grant Nos. 12061059 and 61763041)
Rights and permissions
About this article
Cite this article
Mao, Y.P., Wang, Z., Magnant, C. et al. Gallai—Ramsey Number for the Union of Stars. Acta. Math. Sin.-English Ser. 38, 1317–1332 (2022). https://doi.org/10.1007/s10114-022-0467-1
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10114-022-0467-1