Journal of the Korean Physical Society vol. 36, no. 4, pp. 241 - 244
SCI; SCIE; SCOPUS; KCI
We propose a method to recover the time variable and the classical evolution of the Universe from the minisuperspace wave function of the Wheeler-DeWitt equation. Defining a Hamilton-Jacobi characteristic function W as the imaginary part of the ln Ψ, we can recover the classical solution and the quantum corrections. The key idea is to let the energy of the Wheeler-DeWitt equation vanish only after the semiclassical limit is taken.