4D Gauss-Bonnet gravity: cosmological constraints, $H_0$ tension and large scale structure. (arXiv:2103.12358v2 [astro-ph.CO] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Wang_D/0/1/0/all/0/1">Deng Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mota_D/0/1/0/all/0/1">David Mota</a>

We perform correct and reasonable cosmological constraints on the newly
proposed 4D Gauss-Bonnet gravity. Using the joint constraint from cosmic
microwave background, baryon acoustic oscillations, Type Ia supernovae, cosmic
chronometers and redshift space distortions, we obtain, so far, the strongest
constraint $tilde{alpha}=(1.2pm5.2)times 10^{-17}$, namely
$alpha=(2.69pm11.67)times10^{48}$ eV$^{-2}$, among various observational
limitations from different information channels, which is tighter than previous
bound from the speed of gravitational wave by at least one order of magnitude.
We find that our bound is well supported by the observations of temperature and
lensing potential power spectra of cosmic microwave background from the
Planck-2018 final release. Very interestingly, the large $H_0$ tension between
the local measurement from the Hubble Space Telescope and global derivation
from the Planck-2018 final data under the assumption of $Lambda$CDM can be
greatly resolved from $4.4sigma$ to $1.94sigma$ level in the 4D Gauss-Bonnet
gravity. In theory, we find that this model can partly relieve the coincidence
problem and the rescaling Gauss-Bonnet term, which needs the help of the
cosmological constant to explain current cosmic acceleration, is unable to
serve as dark energy alone.

We perform correct and reasonable cosmological constraints on the newly
proposed 4D Gauss-Bonnet gravity. Using the joint constraint from cosmic
microwave background, baryon acoustic oscillations, Type Ia supernovae, cosmic
chronometers and redshift space distortions, we obtain, so far, the strongest
constraint $tilde{alpha}=(1.2pm5.2)times 10^{-17}$, namely
$alpha=(2.69pm11.67)times10^{48}$ eV$^{-2}$, among various observational
limitations from different information channels, which is tighter than previous
bound from the speed of gravitational wave by at least one order of magnitude.
We find that our bound is well supported by the observations of temperature and
lensing potential power spectra of cosmic microwave background from the
Planck-2018 final release. Very interestingly, the large $H_0$ tension between
the local measurement from the Hubble Space Telescope and global derivation
from the Planck-2018 final data under the assumption of $Lambda$CDM can be
greatly resolved from $4.4sigma$ to $1.94sigma$ level in the 4D Gauss-Bonnet
gravity. In theory, we find that this model can partly relieve the coincidence
problem and the rescaling Gauss-Bonnet term, which needs the help of the
cosmological constant to explain current cosmic acceleration, is unable to
serve as dark energy alone.

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