Hi-index | 0.00 |
Given a finite set of complex numbers A we say that a transformation on the complex numbers, T: C → C is k-rich on A if |A ∩ T(A)|≥ k. In this paper we give a bounds on the number of k-rich linear and Möbius transformations for any given set A. Our results have applications to discrete geometry and to additive combinatorics.