Inflationary spacetimes are not past-complete
By A. Borde, A. Guth, A. Vilenkin. 2001
298 citations recorded by the source corpus.
Many inflating spacetimes are likely to violate the weak energy condition, a key assumption of singularity theorems. Here we offer a simple kinematical argument, requiring no energy condition, that a cosmological model which is inflating -- or just expanding sufficiently fast -- must be incomplete in null and timelike past directions. Specifically, we obtain a bound on the integral of the Hubble parameter over a past-directed timelike or null geodesic. Thus inflationary models require physics other than inflation to describe the past boundary of the inflating region of spacetime.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/2cd7ed864ebd4ff6d213680feb5653789fb1a8e2
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In Astronomy and Astrophysics
- M. Bojowald
- Abhay Ashtekar
- Parampreet Singh
- Carlo Rovelli
- E. Wilson-Ewing
- Alejandro Perez
- T. Pawłowski
- Gianluca Calcagni
In Nuclear and High Energy Physics
- M. Bojowald
- Abhay Ashtekar
- Parampreet Singh
- E. Wilson-Ewing
- T. Pawłowski
- Gianluca Calcagni
- Kinjal Banerjee
- M. Mart'in-Benito
Citations in the corpus
- Loop Quantum Cosmology (2005, background): “Since, according to singularity theorems [2, 74], any classical trajectory must intersect the subset a = 0 for the matter we need in our universe, the classical theory is incomplete.”