Long paths in the distance graph over large subsets of vector spaces   over finite fields
  Let $E \subset {\Bbb F}_q^d$, the $d$-dimensional vector space over a finite field with $q$ elements. Construct a graph, called the distance graph of $E$, by letting the vertices be the elements of $E$ and connect a pair of vertices corresponding to vectors $x,y \in E$ by an edge if $||x-y||={(x_1-y_1)}^2+\dots+{(x_d-y_d)}^2=1$. We shall prove that if the size of $E$ is sufficiently large, then the distance graph of $E$ contains long non-overlapping paths and vertices of high degree. 
M. Bennett, J. Chapman, D. Covert, D. Hart, A. Iosevich and J.   Pakianathan
math.CO math.CA math.NT