Cosmological perturbations from an inhomogeneous phase transition
  A mechanism for generating metric perturbations in inflationary models is
considered. Long-wavelength inhomogeneities of light scalar fields in a
decoupled sector may give rise to superhorizon fluctuations of couplings and
masses in the low-energy effective action. Cosmological phase transitions may
then occur that are not simultaneous in space, but occur with time lags in
different Hubble patches that arise from the long-wavelength inhomogeneities.
Here an interesting model in which cosmological perturbations may be created at
the electroweak phase transition is considered. The results show that phase
transitions may be a generic source of non-Gaussianity.
