  The vacuum is filled with complex scalar fields, such as the Higgs field.
These fields serve as order parameters for superfluidity (quantum phase
coherence over macroscopic distances), making the entire universe a superfluid.
We review a mathematical model consisting of two aspects: (a) emergence of the
superfluid during the big bang; (b) observable manifestations of superfluidity
in the present universe. The creation aspect requires a self-interacting scalar
field that is asymptotically free, i.e., the interaction must grow from zero
during the big bang, and this singles out the Halpern-Huang potential, which
has exponential behavior for large fields. It leads to an equivalent
cosmological constant that decays like a power law, and this gives dark energy
without "fine-tuning". Quantum turbulence (chaotic vorticity) in the early
universe was able to create all the matter in the universe, fulfilling the
inflation scenario. In the present universe, the superfluid can be
phenomenologically described by a nonlinear Klein-Gordon equation. It predicts
halos around galaxies with higher superfluid density, which is perceived as
dark matter through gravitational lensing. In short, dark energy is the energy
density of the cosmic superfluid, and dark matter arises from local
fluctuations of the superfluid density.
