English

Ultralocality and Slow Contraction

General Relativity and Quantum Cosmology 2021-06-09 v1 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

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.

Keywords

Cite

@article{arxiv.2103.00584,
  title  = {Ultralocality and Slow Contraction},
  author = {Anna Ijjas and Andrew P. Sullivan and Frans Pretorius and Paul J. Steinhardt and William G. Cook},
  journal= {arXiv preprint arXiv:2103.00584},
  year   = {2021}
}

Comments

27 pages, 10 figures

R2 v1 2026-06-23T23:35:29.669Z