On the Hubble constant tension in the SNe Ia Pantheon sample. (arXiv:2103.02117v4 [astro-ph.CO] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Dainotti_M/0/1/0/all/0/1">Maria Giovanna Dainotti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Simone_B/0/1/0/all/0/1">Biagio De Simone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schiavone_T/0/1/0/all/0/1">Tiziano Schiavone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Montani_G/0/1/0/all/0/1">Giovanni Montani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rinaldi_E/0/1/0/all/0/1">Enrico Rinaldi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lambiase_G/0/1/0/all/0/1">Gaetano Lambiase</a>
The Hubble constant ($H_0$) tension between Type Ia Supernovae (SNe Ia) and
Planck measurements ranges from 4 to 6 $sigma$. To investigate this tension,
we estimate $H_{0}$ in the $Lambda$CDM and $w_{0}w_{a}$CDM models by dividing
the Pantheon sample, the largest compilation of SNe Ia, into 3, 4, 20 and 40
bins. We fit the extracted $H_{0}$ values with a function mimicking the
redshift evolution: $g(z)={H_0}(z)=tilde{H}_0/(1+z)^alpha$, where $alpha$
indicates an evolutionary parameter and $tilde{H}_0=H_0$ at $z=0$. We set the
absolute magnitude of SNe Ia so that $H_0=73.5,, textrm{km
s}^{-1},textrm{Mpc}^{-1}$, and we fix fiducial values for
$Omega_{0m}^{Lambda CDM}=0.298$ and $Omega_{0m}^{w_{0}w_{a}CDM}=0.308$.
We find that $H_0$ evolves with redshift, showing a slowly decreasing trend,
with $alpha$ coefficients consistent with zero only from 1.2 to 2.0 $sigma$.
Although the $alpha$ coefficients are compatible with 0 in 3 $sigma$, this
however may affect cosmological results. We measure locally a variation of
$H_0(z=0)-H_0(z=1)=0.4, textrm{km s}^{-1},textrm{Mpc}^{-1}$ in 3 and 4
bins. Extrapolating ${H_0}(z)$ to $z=1100$, the redshift of the last scattering
surface, we obtain values of $H_0$ compatible in 1 $sigma$ with Planck
measurements independently of cosmological models and number of bins we
investigated. Thus, we have reduced the $H_0$ tension from $54%$ to $72%$ for
the $Lambda$CDM and $w_{0}w_{a}$CDM models, respectively. If the decreasing
trend of $H_0(z)$ is real, it could be due to astrophysical selection effects
or to modified gravity.
The Hubble constant ($H_0$) tension between Type Ia Supernovae (SNe Ia) and
Planck measurements ranges from 4 to 6 $sigma$. To investigate this tension,
we estimate $H_{0}$ in the $Lambda$CDM and $w_{0}w_{a}$CDM models by dividing
the Pantheon sample, the largest compilation of SNe Ia, into 3, 4, 20 and 40
bins. We fit the extracted $H_{0}$ values with a function mimicking the
redshift evolution: $g(z)={H_0}(z)=tilde{H}_0/(1+z)^alpha$, where $alpha$
indicates an evolutionary parameter and $tilde{H}_0=H_0$ at $z=0$. We set the
absolute magnitude of SNe Ia so that $H_0=73.5,, textrm{km
s}^{-1},textrm{Mpc}^{-1}$, and we fix fiducial values for
$Omega_{0m}^{Lambda CDM}=0.298$ and $Omega_{0m}^{w_{0}w_{a}CDM}=0.308$.
We find that $H_0$ evolves with redshift, showing a slowly decreasing trend,
with $alpha$ coefficients consistent with zero only from 1.2 to 2.0 $sigma$.
Although the $alpha$ coefficients are compatible with 0 in 3 $sigma$, this
however may affect cosmological results. We measure locally a variation of
$H_0(z=0)-H_0(z=1)=0.4, textrm{km s}^{-1},textrm{Mpc}^{-1}$ in 3 and 4
bins. Extrapolating ${H_0}(z)$ to $z=1100$, the redshift of the last scattering
surface, we obtain values of $H_0$ compatible in 1 $sigma$ with Planck
measurements independently of cosmological models and number of bins we
investigated. Thus, we have reduced the $H_0$ tension from $54%$ to $72%$ for
the $Lambda$CDM and $w_{0}w_{a}$CDM models, respectively. If the decreasing
trend of $H_0(z)$ is real, it could be due to astrophysical selection effects
or to modified gravity.
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