An open universe from valley bounce

It appears difficult to construct a simple model for an open universe based on the one bubble inflationary scenario. The reason is that one needs a la rge mass to avoid the tunneling via the Hawking-Moss solution and a small m ass for successful slow-rolling. However, Rubakov and Sibiryakov suggest th at the Hawking-Moss solution is not a solution for the false vacuum decay p rocess because it does not satisfy the boundary condition. Hence, we have r econsidered the arguments for the defect of the simple polynomial model. We point out the possibility that one of the valley bounce belonging to a val ley line in the functional space represents the decay process instead of th e Hawking-Moss solution. Under this presumption, we show an open inflation model can be constructed within the polynomial form of the potential so tha t the fluctuations can be reconciled with the observations. (C) 2000 Elsevi er Science B.V. All rights reserved.