New Candidates Welcome! Possible Winners with respect to the Addition of   New Candidates
  In voting contexts, some new candidates may show up in the course of the process. In this case, we may want to determine which of the initial candidates are possible winners, given that a fixed number $k$ of new candidates will be added. We give a computational study of this problem, focusing on scoring rules, and we provide a formal comparison with related problems such as control via adding candidates or cloning. 
Yann Chevaleyre, J\'er\^ome Lang, Nicolas Maudet, J\'er\^ome Monnot,   Lirong Xia
cs.AI