$\Lambda$ is Coming: Parametrizing Freezing Fields
  We explore freezing dark energy, where the evolution of the field approaches
that of a cosmological constant at late times. We propose two general, two
parameter forms to describe the class of freezing field models, in analogy to
ones for thawing fields, here based on the physics of the flow parameter or the
calibrated $w$-$w'$ phase space. Observables such as distances and Hubble
parameters are fit to within 0.1%, and the dark energy equation of state
generally to within better than 1%, of the exact numerical solutions.
