PreprintCC BY 4.0arXiv
An 8+9 gluing computation for the Ramsey number R(F3,F4)
Abstract
Let Ft be the graph consisting of t triangles with a common vertex and otherwise disjoint vertices. We prove that R(F3,F4)=17 using an 8+9 gluing computation. Neighbourhood matching arguments give degree and clique restrictions that reduce the search on seventeen vertices to $88,294,674$ ordered seed pairs. The verified main computation excludes $88,294,634$ pairs. A cross-edge counting argument excludes thirty-four of the forty exceptional pairs, and independently checked finite-domain certificates exclude the remaining six. Together with the construction whose red graph is the complete bipartite graph K8,8, these results establish R(F3,F4)=17.
Related
BibTeX
@misc{jiang2026gluing,
title = {{An $8+9$ gluing computation for the Ramsey number $R(F_3,F_4)$}},
author = {Hanxin Jiang and Zehui Shao},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26109},
eprint = {2610.26109},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26109},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - An 8+9 gluing computation for the Ramsey number R(F_3,F_4)
AU - Hanxin Jiang
AU - Zehui Shao
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26109
UR - https://arxiv.org/abs/2610.26109
AB - Let F_t be the graph consisting of t triangles with a common vertex and otherwise disjoint vertices. We prove that R(F_3,F_4)=17 using an 8+9 gluing computation. Neighbourhood matching arguments give degree and clique restrictions that reduce the search on seventeen vertices to $88,294,674$ ordered seed pairs. The verified main computation excludes $88,294,634$ pairs. A cross-edge counting argument excludes thirty-four of the forty exceptional pairs, and independently checked finite-domain certificates exclude the remaining six. Together with the construction whose red graph is the complete bipartite graph K_8,8, these results establish R(F_3,F_4)=17.
ER -