Big bang as a topological quantum phase transition

It has been argued that a particular type of quantum-vacuum variable q can provide a solution to the main cosmological constant problem and possibly also give a cold-dark-matter component. We now show that the same q field may suggest a new interpretation of the big bang, namely as a quantum phase transition between topologically inequivalent vacua. These two vacua are characterized by the equilibrium values q=±q0, and there is a kink-type solution q(t) interpolating between q=−q0 for t→−∞ and q=+q0 for t→∞, with conformal symmetry for q=0 at t=0.