Difference sets and positive exponential sums I. General properties
  We describe general connections between intersective properties of sets in Abelian groups and positive exponential sums. In particular, given a set $A$ the maximal size of a set whose difference set avoids $A$ will be related to positive exponential sums using frequencies from $A$. 
Mate Matolcsi, Imre Z. Ruzsa
math.CO math.NT