On off-diagonal Ramsey numbers for vector spaces over $\mathbb{F}_{2}$
Abstract
For every positive integer , we show that there must exist an absolute constant such that the following holds: for any integer and any red-blue coloring of the one-dimensional subspaces of , there must exist either a -dimensional subspace for which all of its one-dimensional subspaces get colored red or a -dimensional subspace for which all of its one-dimensional subspaces get colored blue. This answers recent questions of Nelson and Nomoto, and confirms that for any even plane binary matroid , the class of -free, claw-free binary matroids is polynomially -bounded. Our argument will proceed via a reduction to a well-studied additive combinatorics problem, originally posed by Green: given a set with density , what is the largest subspace that we can find in ? Our main contribution to the story is a new result for this problem in the regime where is large with respect to , which utilizes ideas from the recent breakthrough paper of Kelley and Meka on sets of integers without three-term arithmetic progressions.
Cite
@article{arxiv.2309.02424,
title = {On off-diagonal Ramsey numbers for vector spaces over $\mathbb{F}_{2}$},
author = {Zach Hunter and Cosmin Pohoata},
journal= {arXiv preprint arXiv:2309.02424},
year = {2024}
}
Comments
incorporated referee comments; to appear in Math. Proc. Camb. Phil. Soc