The tunneling hamiltonian representation of false vacuum decay V.   Application to cosmological constant question
  The tunneling Hamiltonian has proven to be a useful method in many body physics to treat particle tunneling between different states represented as wavefunctions. Here we apply a generalization of the way we formed appropriate wave functionals for charge density waves to how to present nucleation of an inflationary universe. This allows us to make a first order phase transition to initiate nucleation of an inflationary universe, in which tunneling between states which are wave functionals of a scalar quantum field are considered. Our prior article showed us how we can have particle - anti particle pairs as a model of how nucleation occurs and construct a potential which may permit formation of dark matter, using Sherrers k essence model construction. This same construction permits a definitive analysis of when conditions for pure cosmological constant behavior but no growth of density pertubations occur, largely as a matter of change of slope of a soliton-anti soliton pair during the nucleation process of a new universe. 
A.W. Beckwith