Ranks of gauge groups and an NP-complete problem on the Landscape
  We prove that the problem of determination of factor gauge groups given the rank of the gauge group at any given vacuum in the Landscape is in the computational complexity class NPC. This extends a result of Denef and Douglas on the computational complexity of determination of the value of the cosmological constant in the Landscape. 
Abhijnan Rej
math-ph hep-th math.MP