Comparison of two methods for calculating nucleation rates

First-order phase transitions that proceed via nucleation of bubbles are de scribed by the homogeneous nucleation theory of Langer. The nucleation rate is one of the most interesting parameters of these transitions, In previou s works we have computed nucleation rates with two different methods. (A) e mploying coarse-grained potentials; (B) by means of a saddle-point approxim ation, using dimensionally regularized field theory. In this Letter we comp are the results of the two approaches in order to test their reliability an d to determine the regions of applicability, We find a very good agreement. (C) 2000 Elsevier Science B.V. All rights reserved.