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Article Dans Une Revue Physical Review D Année : 2023

Spatial Curvature from Super-Hubble Cosmological Fluctuations

Baptiste Blachier
  • Fonction : Auteur
Pierre Auclair
Christophe Ringeval
  • Fonction : Auteur
Vincent Vennin

Résumé

We revisit how super-Hubble cosmological fluctuations induce, at any time in the cosmic history, a non-vanishing spatial curvature of the local background metric. The random nature of these fluctuations promotes the curvature density parameter to a stochastic quantity for which we derive novel non-perturbative expressions for its mean, variance, higher moments and full probability distribution. For scale-invariant Gaussian perturbations, such as those favored by cosmological observations, we find that the most probable value for the curvature density parameter $\Omega_\mathrm{K}$ today is $-10^{-9}$, that its mean is $+10^{-9}$, both being overwhelmed by a standard deviation of order $10^{-5}$. We then discuss how these numbers would be affected by the presence of large super-Hubble non-Gaussianities, or, if inflation lasted for a very long time. In particular, we find that substantial values of $\Omega_\mathrm{K}$ are obtained if inflation lasts for more than a billion e-folds.

Dates et versions

hal-04038864 , version 1 (21-03-2023)

Identifiants

Citer

Baptiste Blachier, Pierre Auclair, Christophe Ringeval, Vincent Vennin. Spatial Curvature from Super-Hubble Cosmological Fluctuations. Physical Review D, 2023, 108 (12), pp.123510. ⟨10.1103/PhysRevD.108.123510⟩. ⟨hal-04038864⟩
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