Graceful exit from inflation using quantum cosmology

A massless scalar field without self-interaction and string coupled to grav ity is quantized in the framework of quantum cosmology using the Bohm-de Br oglie interpretation. Gaussian superpositions of the quantum solutions of t he corresponding Wheeler-DeWitt equation in minisuperspace are constructed. The Bohmian trajectories obtained exhibit a graceful exit from the inflati onary pre-big, bang epoch to the decelerated expansion phase. (C) 2001 Else vier Science B.V. All rights reserved.