A note on strong Erdős-Hajnal for graphs with bounded VC-minimal complexity
Yayi Fu
TL;DR
For any $N in\mathbb{N}^{>0}$, there is $k_N>0$ such that for any finite bipartite graph $(X,Y;E) with VC-minimal complexity $<N, there exist $X'\subseteq X$ and $Y'\ subseteq Y$.
Abstract
Inspired by Adler's idea on VC minimal theories \cite{adler2008theories}, we introduce VC-minimal complexity. We show that for any $N\in\mathbb{N}^{>0}$, there is $k_N>0$ such that for any finite bipartite graph $(X,Y;E)$ with VC-minimal complexity $< N$, there exist $X'\subseteq X$, $Y'\subseteq Y$ with $|X'|\geq k_N |X|$, $|Y'|\geq k_N |Y|$ such that $X'\times Y' \subseteq E$ or $X'\times Y'\cap E=\emptyset$.
