Maximizing the Cohesion is NP-hard
  We show that the problem of finding a set with maximum cohesion in an undirected network is NP-hard. 
Adrien Friggeri (ENS / LIP Laboratoire de l'Informatique du   Parall\'elisme / INRIA Grenoble Rh\^one-Alpes, IXXI), Eric Fle...
cs.NI cs.CC