Abstract
For graphs G< and H< with linearly ordered vertex sets, the ordered Ramsey number r< (G<, H<) is the smallest positive integer N such that any red-blue coloring of the edges of the complete ordered graph KN< on N vertices contains either a blue copy of G< or a red copy of H<. Motivated by a problem of Conlon, Fox, Lee, and Sudakov (2017), we study the numbers r< (M<, K3<) whereM < is an ordered matching on n vertices. We prove that almost all n-vertex ordered matchings M< with interval chromatic number 2 satisfy r< (M<, K3<)∈Ω((n/logn)5/4) and r< (M<, K3<)∈ O(n7/4), improving a recent result by Rohatgi (2019). We also show that there are nvertex ordered matchings M< with interval chromatic number at least 3 satisfying r< (M<, K3<)∈Ω((n/logn)4/3), which asymptotically matches the best known lower bound on these off-diagonal ordered Ramsey numbers for general n-vertex ordered matchings.
Original language | English |
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Article number | P2.23 |
Journal | Electronic Journal of Combinatorics |
Volume | 31 |
Issue number | 2 |
DOIs | |
State | Published - 1 Jan 2024 |
Externally published | Yes |
ASJC Scopus subject areas
- Theoretical Computer Science
- Geometry and Topology
- Discrete Mathematics and Combinatorics
- Computational Theory and Mathematics
- Applied Mathematics