English

On a Quantum Weyl Curvature Hypothesis

General Relativity and Quantum Cosmology 2022-04-04 v2 Quantum Physics

Abstract

Roger Penrose's Weyl curvature hypothesis states that the Weyl curvature is small at past singularities, but not at future singularities. We review the motivations for this conjecture and present estimates for the entropy of our Universe. We then extend this hypothesis to the quantum regime by demanding that the initial state of primordial quantum fluctuations be the adiabatic vacuum in a (quasi-) de~Sitter space. We finally attempt a justification of this quantum version from a fundamental theory of quantum gravity and speculate on its consequences in the case of a classically recollapsing universe.

Keywords

Cite

@article{arxiv.2111.02137,
  title  = {On a Quantum Weyl Curvature Hypothesis},
  author = {Claus Kiefer},
  journal= {arXiv preprint arXiv:2111.02137},
  year   = {2022}
}

Comments

13 pages, Invited contribution for a special topical collection celebrating Sir Roger Penrose's Nobel Prize, ed. by I. Fuentes and H. Ulbricht, final version

R2 v1 2026-06-24T07:24:09.056Z