A bipartite class of entanglement monotones for N-qubit pure states
  We construct a class of algebraic invariants for N-qubit pure states based on bipartite decompositions of the system.   We show that they are entanglement monotones, and that they differ from the well know linear entropies of the sub-systems. They therefore capture new information on the non-local properties of multipartite systems. 
Clive Emary