The Role of Fermions in Bubble Nucleation
  We present a study of the role of fermions in the decay of metastable states of a scalar field via bubble nucleation. We analyze both one and three-dimensional systems by using a gradient expansion for the calculation of the fermionic determinant. The results of the one-dimensional case are compared to the exact results of previous work. 
D.G. Barci, E.S. Fraga and C.A.A. de Carvalho