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 s 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.
Original language | English (US) |
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Article number | 030 |
Journal | Journal of Cosmology and Astroparticle Physics |
Volume | 2021 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2021 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
Keywords
- alternatives to inflation
- cosmological simulations
- gravity
- physics of the early universe