A note on the size Ramsey numbers for matchings versus cycles

Edy Tri Baskoro; Tomáš Vetrík

Mathematica Bohemica (2021)

  • Volume: 146, Issue: 2, page 229-234
  • ISSN: 0862-7959

Abstract

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For graphs G , F 1 , F 2 , we write G ( F 1 , F 2 ) if for every red-blue colouring of the edge set of G we have a red copy of F 1 or a blue copy of F 2 in G . The size Ramsey number r ^ ( F 1 , F 2 ) is the minimum number of edges of a graph G such that G ( F 1 , F 2 ) . Erdős and Faudree proved that for the cycle C n of length n and for t 2 matchings t K 2 , the size Ramsey number r ^ ( t K 2 , C n ) < n + ( 4 t + 3 ) n . We improve their upper bound for t = 2 and t = 3 by showing that r ^ ( 2 K 2 , C n ) n + 2 3 n + 9 for n 12 and r ^ ( 3 K 2 , C n ) < n + 6 n + 9 for n 25 .

How to cite

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Baskoro, Edy Tri, and Vetrík, Tomáš. "A note on the size Ramsey numbers for matchings versus cycles." Mathematica Bohemica 146.2 (2021): 229-234. <http://eudml.org/doc/297486>.

@article{Baskoro2021,
abstract = {For graphs $G$, $F_1$, $F_2$, we write $G \rightarrow (F_1, F_2)$ if for every red-blue colouring of the edge set of $G$ we have a red copy of $F_1$ or a blue copy of $F_2$ in $G$. The size Ramsey number $\hat\{r\}(F_1, F_2)$ is the minimum number of edges of a graph $G$ such that $G \rightarrow (F_1, F_2)$. Erdős and Faudree proved that for the cycle $C_n$ of length $n$ and for $t \ge 2$ matchings $tK_2$, the size Ramsey number $\hat\{r\} (tK_2, C_n) < n + (4t+3) \sqrt\{n\}$. We improve their upper bound for $t = 2$ and $t=3$ by showing that $\hat\{r\} (2K_2, C_n) \le n + 2 \sqrt\{3n\} + 9$ for $n \ge 12$ and $\hat\{r\} (3K_2, C_n) < n + 6 \sqrt\{n\} + 9$ for $n \ge 25$.},
author = {Baskoro, Edy Tri, Vetrík, Tomáš},
journal = {Mathematica Bohemica},
keywords = {size Ramsey number; matching; cycle},
language = {eng},
number = {2},
pages = {229-234},
publisher = {Institute of Mathematics, Academy of Sciences of the Czech Republic},
title = {A note on the size Ramsey numbers for matchings versus cycles},
url = {http://eudml.org/doc/297486},
volume = {146},
year = {2021},
}

TY - JOUR
AU - Baskoro, Edy Tri
AU - Vetrík, Tomáš
TI - A note on the size Ramsey numbers for matchings versus cycles
JO - Mathematica Bohemica
PY - 2021
PB - Institute of Mathematics, Academy of Sciences of the Czech Republic
VL - 146
IS - 2
SP - 229
EP - 234
AB - For graphs $G$, $F_1$, $F_2$, we write $G \rightarrow (F_1, F_2)$ if for every red-blue colouring of the edge set of $G$ we have a red copy of $F_1$ or a blue copy of $F_2$ in $G$. The size Ramsey number $\hat{r}(F_1, F_2)$ is the minimum number of edges of a graph $G$ such that $G \rightarrow (F_1, F_2)$. Erdős and Faudree proved that for the cycle $C_n$ of length $n$ and for $t \ge 2$ matchings $tK_2$, the size Ramsey number $\hat{r} (tK_2, C_n) < n + (4t+3) \sqrt{n}$. We improve their upper bound for $t = 2$ and $t=3$ by showing that $\hat{r} (2K_2, C_n) \le n + 2 \sqrt{3n} + 9$ for $n \ge 12$ and $\hat{r} (3K_2, C_n) < n + 6 \sqrt{n} + 9$ for $n \ge 25$.
LA - eng
KW - size Ramsey number; matching; cycle
UR - http://eudml.org/doc/297486
ER -

References

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  1. Effendi, Ginting, B., Surahmat, Dafik, Sy, S., 10.17654/MS102030507, Far East J. Math. Sci. (FJMS) 102 (2017), 507-514. (2017) Zbl1378.05125DOI10.17654/MS102030507
  2. Erdős, P., Faudree, R. J., 10.1016/B978-0-444-86893-0.50019-X, Finite and Infinite Sets. Vol. I, II (Eger, 1981) Colloquia Mathematica Societatis János Bolyai 37. János Bolyai Mathematical Society, Budapest; North-Holland, Amsterdam (1984), 247-264 A. Hajnal et al. (1984) Zbl0563.05043MR0818238DOI10.1016/B978-0-444-86893-0.50019-X
  3. Erdős, P., Faudree, R. J., Rousseau, C. C., Schelp, R. H., 10.1007/BF02018930, Period. Math. Hung. 9 (1978), 145-161. (1978) Zbl0331.05122MR0479691DOI10.1007/BF02018930
  4. Faudree, R. J., Sheehan, J., 10.1002/jgt.3190070107, J. Graph Theory 7 (1983), 53-55. (1983) Zbl0505.05043MR0693020DOI10.1002/jgt.3190070107
  5. Ke, X., 10.1002/rsa.3240040106, Random Struct. Algorithms 4 (1993), 85-97. (1993) Zbl0778.05060MR1192528DOI10.1002/rsa.3240040106
  6. Lortz, R., Mengersen, I., Size Ramsey results for paths versus stars, Australas. J. Comb. 18 (1998), 3-12. (1998) Zbl0914.05053MR1658352
  7. Perondi, P. H., Carmelo, E. L. Monte, 10.1016/j.dam.2018.05.016, Discrete Appl. Math. 250 (2018), 368-372. (2018) Zbl1398.05131MR3868682DOI10.1016/j.dam.2018.05.016

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