Recursive Lifting Beyond the Ahlswede--Khachatrian Construction
Combinatorics
2026-07-06 v1
Abstract
For the Erd\H{o}s--Frankl--Pach problem on uniform set systems of bounded VC-dimension, the Ahlswede--Khachatrian/Mubayi--Zhao construction has long served as the standard lower-bound benchmark. We develop a recursive lifting method that goes beyond this benchmark in every dimension , proving that for every and , The proof is elementary and proceeds through explicit trace obstructions. We also record a further recursive improvement in the concluding remarks.
Cite
@article{arxiv.2607.04858,
title = {Recursive Lifting Beyond the Ahlswede--Khachatrian Construction},
author = {Xiaochen Zhao and Gennian Ge},
journal= {arXiv preprint arXiv:2607.04858},
year = {2026}
}
Comments
8 pages. A separate manuscript building on arXiv:2606.22064, with a new augmentation yielding a further recursive lower bound