Abstract
It is argued that ‘‘eternal inflation’’ must have a beginning in time. Conditions are formulated for a spacetime to describe an eternally inflating universe without a beginning, and it is shown that these conditions cannot be satisfied. A rigorous proof is given for a two-dimensional spacetime, and a plausibility argument for four dimensions.
- Received 3 August 1992
DOI:https://doi.org/10.1103/PhysRevD.46.2355
©1992 American Physical Society