  For a rather general class of scenarios, sweeping through a zero-temperature
phase transition by means of a time-dependent external parameter entails
universal behavior: In the vicinity of the critical point, excitations behave
as quantum fields in an expanding or contracting universe. The resulting
effects such as the amplification or suppression of quantum fluctuations (due
to horizon crossing, freezing, and squeezing) including the induced spectrum
can be derived using the curved space-time analogy. The observed similarity
entices the question of whether cosmic inflation itself might perhaps have been
such a phase transition. PACS: 73.43.Nq, 04.62.+v, 98.80.Cq, 04.80.-y.
