Group construction in non-trivial geometric $C$-minimal structures
  We show that an infinite group is definable in any non trivial geometric $C$-minimal structure which is definably maximal and does not have any definable bijection between a bounded interval and an unbounded one in its canonical tree. No kind of linearity is assumed. 
Fran\c{c}oise Delon and Fares Maalouf
math.LO