English

Dynamical attractors in contracting spacetimes dominated by kinetically coupled scalar fields

General Relativity and Quantum Cosmology 2021-12-14 v1 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

We present non-perturbative numerical relativity simulations of slowly contracting spacetimes in which the scalar field driving slow contraction is coupled to a second scalar field through an exponential non-linear sigma model-type kinetic interaction. These models are important because they can generate a nearly scale-invariant spectrum of super-Hubble density fluctuations fully consistent with cosmic microwave background observations. We show that the non-linear evolution rapidly approaches a homogeneous, isotropic and flat Friedmann- Robertson-Walker (FRW) geometry for a wide range of inhomogeneous and anisotropic initial conditions. Ultimately, we find, the kinetic coupling causes the evolution to deflect away from flat FRW and towards a novel Kasner-like stationary point, but in general this occurs on time scales that are too long to be observationally relevant.

Keywords

Cite

@article{arxiv.2109.09768,
  title  = {Dynamical attractors in contracting spacetimes dominated by kinetically coupled scalar fields},
  author = {Anna Ijjas and Frans Pretorius and Paul J. Steinhardt and David Garfinkle},
  journal= {arXiv preprint arXiv:2109.09768},
  year   = {2021}
}

Comments

25 pages, 5 figures

R2 v1 2026-06-24T06:09:23.775Z