Wave packets and initial conditions in quantum cosmology

We discuss the construction of wave packets resulting from the solutions of a class of Wheeler-DeWitt equations in Robertson-Walker type cosmologies. We present an ansatz for the initial conditions which leads to a unique det ermination of the expansion coefficients in the construction of the wave pa ckets with probability distributions which, in an interesting contrast to s ome of the earlier works, agree well with all possible classical paths. The possible relationship between these initial conditions and signature trans ition in the context of classical cosmology is also discussed. (C) 2000 Els evier Science B.V. All rights reserved. PACS: 04.60.-m; 04.20.-q: 03.50. h.