An analog of the Furstenberg-Katznelson-Weiss theorem on triangles in sets of positive density in finite field geometries
arXiv:0804.4894
Abstract
We prove that if the cardinality of a subset of the 2-dimensional vector space over a finite field with $q$ elements is $\ge Ïq^2$, with $\frac{1}{\sqrt{q}}<<Ï\leq 1$, then it contains an isometric copy of $\ge cÏq^3$ triangles.