PreprintCC BY 4.0arXiv
Seeking the dense half in K4-free graphs
Abstract
We show that every K4-free graph on n vertices has a balanced bipartition such that neither part contains more than 0.0671n2 + o(n2) edges. This improves the previous best bound of 0.074n2 by Xu and Zhang. We also formulate a conjecture that the tight bound for this problem is 425/6498n2 ≈ 0.0654n2, and present a construction showing that it would be best possible.
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BibTeX
@misc{buczek2026seeking,
title = {{Seeking the dense half in $K_4$-free graphs}},
author = {Ignacy Buczek and Andrzej Grzesik and Piotr Kuc},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.07082},
eprint = {2611.07082},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.07082},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Seeking the dense half in K_4-free graphs
AU - Ignacy Buczek
AU - Andrzej Grzesik
AU - Piotr Kuc
PY - 2026
DA - 2026/11/04
PB - arXiv
DO - 10.48550/arxiv.2611.07082
UR - https://arxiv.org/abs/2611.07082
AB - We show that every K_4-free graph on n vertices has a balanced bipartition such that neither part contains more than 0.0671n^2 + o(n^2) edges. This improves the previous best bound of 0.074n^2 by Xu and Zhang. We also formulate a conjecture that the tight bound for this problem is 425/6498n^2 ≈ 0.0654n^2, and present a construction showing that it would be best possible.
ER -