The effects of multiple modes and reduced symmetry on the rapidity and robustness of slow contraction

Research output: Contribution to journal › Article › Research › peer review

Authors

  • Anna Ijjas
  • Frans Pretorius
  • Paul J. Steinhardt
  • Andrew P. Sullivan

Research Organisations

External Research Organisations

  • Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
  • Princeton University
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Details

Original languageEnglish
Article number136490
JournalPhysics Letters B
Volume820
Early online date1 Jul 2021
Publication statusPublished - 10 Sept 2021

Abstract

We demonstrate that the rapidity and robustness of slow contraction in homogenizing and flattening the universe found in simulations in which the initial conditions were restricted to non-perturbative variations described by a single Fourier mode along only a single spatial direction are in general enhanced if the initial variations are along two spatial directions, include multiple modes, and thereby have reduced symmetry. Particularly significant are shear effects that only become possible when variations are allowed along two or more spatial dimensions. Based on the numerical results, we conjecture that the counterintuitive enhancement occurs because more degrees of freedom are activated which drive spacetime away from an unstable Kasner fixed point and towards the stable Friedmann-Robertson-Walker fixed point. (C) 2021 The Authors. Published by Elsevier B.V.

Keywords

    Slow contraction, Homogeneity, Isotropy, Mode coupling, Numerical relativity, Bouncing/cyclic cosmology

ASJC Scopus subject areas

Cite this

The effects of multiple modes and reduced symmetry on the rapidity and robustness of slow contraction. / Ijjas, Anna; Pretorius, Frans; Steinhardt, Paul J. et al.
In: Physics Letters B, Vol. 820, 136490, 10.09.2021.

Research output: Contribution to journal › Article › Research › peer review

Ijjas A, Pretorius F, Steinhardt PJ, Sullivan AP. The effects of multiple modes and reduced symmetry on the rapidity and robustness of slow contraction. Physics Letters B. 2021 Sept 10;820:136490. Epub 2021 Jul 1. doi: 10.1016/j.physletb.2021.136490
Ijjas, Anna ; Pretorius, Frans ; Steinhardt, Paul J. et al. / The effects of multiple modes and reduced symmetry on the rapidity and robustness of slow contraction. In: Physics Letters B. 2021 ; Vol. 820.
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AU - Steinhardt, Paul J.

AU - Sullivan, Andrew P.

N1 - Funding Information: The work of A.I. is supported by the Lise Meitner Excellence Program of the Max Planck Society and the Simons Foundation grant number 663083 . F.P. acknowledges support from NSF grant PHY-1912171 , the Simons Foundation grant number 256111 , and the Canadian Institute for Advanced Research (CIFAR) grant number FS20-056 . P.J.S. supported in part by the DOE grant number DEFG02-91ER40671 and by the Simons Foundation grant number 654561 . A.P.S. is also supported by the Simons Foundation grant number 654561 .

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