Sailing through the big crunchbig bang transition
Abstract
In a recent series of papers, we have shown that theories with scalar fields coupled to gravity (e.g., the standard model) can be lifted to a Weylinvariant equivalent theory in which it is possible to unambiguously trace the classical cosmological evolution through the transition from big crunch to big bang. The key was identifying a sufficient number of finite, Weylinvariant conserved quantities to uniquely match the fundamental cosmological degrees of freedom across the transition. In doing so we had to account for the wellknown fact that many Weylinvariant quantities diverge at the crunch and bang. Recently, some authors rediscovered a few of these divergences and concluded based on their existence alone that the theories cannot be geodesically complete. In this paper, we show that this conclusion is invalid. Using conserved quantities we explicitly construct the complete set of geodesics and show that they pass continuously through the big crunchbig bang transition.
 Publication:

Physical Review D
 Pub Date:
 March 2014
 DOI:
 10.1103/PhysRevD.89.061302
 arXiv:
 arXiv:1312.0739
 Bibcode:
 2014PhRvD..89f1302B
 Keywords:

 98.80.k;
 98.80.Cq;
 Cosmology;
 Particletheory and fieldtheory models of the early Universe;
 High Energy Physics  Theory;
 Astrophysics  Cosmology and Extragalactic Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 3 pages, 1 figure. In version v2 the last three paragraphs include a response to the Note added to Ref. 18