OPEN INFLATION WITHOUT FALSE VACUA

We show that within the framework of a definite proposal for the initi al conditions for the universe, the Hartle-Hawking ''no boundary'' pro posal, open inflation is generic and does not require any special prop erties of the inflaton potential. in the simplest inflationary models, the semiclassical approximation to the Euclidean path integral and a minimal anthropic condition lead to Omega(0) approximate to 0.01. This number may be increased in models with more fields or extra dimension s. (C) 1998 Published by Elsevier Science B.V. All rights reserved.