Dynamical attractors in contracting spacetimes dominated by kinetically coupled scalar fields
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.
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