Hyperintegers and Nonstandard Techniques in Combinatorics of Numbers
  In literature, many important combinatorial properties of subsets of N have been studied both with nonstandard techniques and from the point of view of N. In this thesis we mix these two different approaches in a technique that, at the same time, incorporates nonstandard tools and ultrafilters. 
Lorenzo Luperi Baglini
math.LO math.CO