English

Geodesic completeness, cosmological bounces and inflation

General Relativity and Quantum Cosmology 2024-09-20 v2 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

The question of geodesic completeness of cosmological spacetimes has recently received renewed scrutiny. A particularly interesting result is the observation that the well-known Borde-Guth-Vilenkin (BGV) theorem may misdiagnose geodesically complete cosmologies. We propose a simple amendment to the BGV theorem which addresses such loopholes while retaining much of its generality. We give straightforward proofs of some recently offered conjectures concerning (generalized) Friedmann-Lema\^itre-Robertson-Walker spacetimes: geodesic completeness implies (i) the existence of a bounce, loitering phase or an emergent cosmology, and (ii) a phase of accelerated expansion with strictly increasing Hubble rate. Our results are purely kinematic and do not assume general relativity or energy conditions.

Keywords

Cite

@article{arxiv.2405.04062,
  title  = {Geodesic completeness, cosmological bounces and inflation},
  author = {Sebastian Garcia-Saenz and Junjie Hua and Yunke Zhao},
  journal= {arXiv preprint arXiv:2405.04062},
  year   = {2024}
}

Comments

5 pages; v2: references added

R2 v1 2026-06-28T16:19:04.163Z