DMGT

ISSN 1234-3099 (print version)

ISSN 2083-5892 (electronic version)

https://doi.org/10.7151/dmgt

Discussiones Mathematicae Graph Theory

Journal Impact Factor (JIF 2022): 0.7

5-year Journal Impact Factor (2022): 0.7

CiteScore (2022): 1.9

SNIP (2022): 0.902

Discussiones Mathematicae Graph Theory

Article in press


Authors:

M. Litka

Mateusz Litka

Adam Mickiewicz University in Poznań

email: matlit@amu.edu.pl

0000-0003-4604-4984

Title:

Online size Ramsey number for $C_4$ and $P_6$

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Source:

Discussiones Mathematicae Graph Theory

Received: 2023-02-15 , Revised: 2023-07-20 , Accepted: 2023-07-21 , Available online: 2023-09-10 , https://doi.org/10.7151/dmgt.2513

Abstract:

In this paper we consider a game played on the edge set of the infinite clique $K_\mathbb{N}$ by two players, Builder and Painter. In each round of the game, Builder chooses an edge and Painter colors it red or blue. Builder wins when Painter creates a red copy of $G$ or a blue copy of $H$, for some fixed graphs $G$ and $H$. Builder wants to win in as few rounds as possible, and Painter wants to delay Builder for as many rounds as possible. The online size Ramsey number $\tilde{r}(G,H)$, is the minimum number of rounds within which Builder can win, assuming both players play optimally. So far it has been proven by Dybizbański, Dzido and Zakrzewska that $11\leq\tilde{r}(C_4,P_6)\leq13$ [J. Dybizbański, T. Dzido and R. Zakrzewska, On-line Ramsey numbers for paths and short cycles, Discrete Appl. Math. 282 (2020) 265–270]. In this paper, we refine this result and show the exact value, namely we will present the theorem that $\tilde{r}(C_4,P_6)=11$, with the details of the proof.

Keywords:

graph theory, Ramsey theory, combinatorial games, online size Ramsey number

References:

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