Bubble Nucleation in Theories with Symmetry Breaking by Radiative   Corrections
  A formalism is developed to calculate the bubble nucleation rate in theories where the symmetry breaking is by radiative corrections. Although to leading and next-to-leading order the result can be expressed in terms of the effective action of the theory, this is not true of the higher order corrections. In particular, the imaginary part of the effective potential does not explicitly enter the calculation and the problems of interpretation which it would entail are avoided. Based on a talk given at the NATO Advanced Research Workshop Electroweak Physics and the Early Universe, Sintra, Portugal, March 25, 1994 
Erick J. Weinberg