Measurement on the cosmic curvature using the Gaussian process method. (arXiv:2007.05714v2 [astro-ph.CO] UPDATED)

Measurement on the cosmic curvature using the Gaussian process method. (arXiv:2007.05714v2 [astro-ph.CO] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Yang_Y/0/1/0/all/0/1">Yingjie Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gong_Y/0/1/0/all/0/1">Yungui Gong</a>

Inflation predicts that the Universe is spatially flat. The Planck 2018
measurements of the cosmic microwave background anisotropy favour a spatially
closed universe at more than 2$sigma$ confidence level. We use model
independent methods to study the issue of cosmic curvature. The method
reconstructs the Hubble parameter $H(z)$ from cosmic chronometers data with the
Gaussian process method. The distance modulus is then calculated with the
reconstructed function $H(z)$ and fitted by type Ia supernovae data. Combining
the cosmic chronometers and type Ia supernovae data, we obtain
$Omega_{k0}h^2=0.102pm 0.066$ which is consistent with a spatially flat
universe at the 2$sigma$ confidence level. By adding the redshift space
distortions data to the type Ia supernovae data with a proposed novel model
independent method, we obtain $Omega_{k0}h^2=0.117^{+0.058}_{-0.045}$ and no
deviation from $Lambda$CDM model is found.

Inflation predicts that the Universe is spatially flat. The Planck 2018
measurements of the cosmic microwave background anisotropy favour a spatially
closed universe at more than 2$sigma$ confidence level. We use model
independent methods to study the issue of cosmic curvature. The method
reconstructs the Hubble parameter $H(z)$ from cosmic chronometers data with the
Gaussian process method. The distance modulus is then calculated with the
reconstructed function $H(z)$ and fitted by type Ia supernovae data. Combining
the cosmic chronometers and type Ia supernovae data, we obtain
$Omega_{k0}h^2=0.102pm 0.066$ which is consistent with a spatially flat
universe at the 2$sigma$ confidence level. By adding the redshift space
distortions data to the type Ia supernovae data with a proposed novel model
independent method, we obtain $Omega_{k0}h^2=0.117^{+0.058}_{-0.045}$ and no
deviation from $Lambda$CDM model is found.

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