Ultralocality and Slow Contraction

Abstract

We study the detailed process by which slow contraction smooths and flattens the universe using an improved numerical relativity code that accepts initial conditions with non-perturbative deviations from homogeneity and isotropy along two independent spatial directions. Contrary to common descriptions of the early universe, we find that the geometry first rapidly converges to an inhomogeneous, spatially-curved and anisotropic ultralocal state in which all spatial gradient contributions to the equations of motion decrease as an exponential in time to negligible values. This is followed by a second stage in which the geometry converges to a homogeneous, spatially flat and isotropic spacetime. In particular, the decay appears to follow the same history whether the entire spacetime or only parts of it are smoothed by the end of slow contraction.

arXiv comment27 pages, 10 figures

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• Dynamical attractors in contracting spacetimes dominated by kinetically coupled scalar fields
• Numerical Relativity as a New Tool for Fundamental Cosmology
• The robustness of slow contraction and the shape of the scalar field potential
• Cuscuton Bounce Beyond the Linear Regime: Bispectrum and Strong Coupling Constraints
• Gauge/frame invariant variables for the numerical relativity study of cosmological spacetimes
• Geodesically complete cyclic cosmologies and entropy
• Torsion, Gravity Induced Chiral Symmetry Breaking and Cosmological Bounce
• Probability of the Initial Conditions for Inflation and Slow Contraction
• Kinetically-driven ekpyrosis