# To H0 or not to H0?

@inproceedings{Efstathiou2021ToHO,
title={To H0 or not to H0?},
author={George P. Efstathiou},
year={2021}
}
This paper investigates whether changes to late time physics can resolve the ‘Hubble tension’. It is argued that many of the claims in the literature favouring such solutions are caused by a misunderstanding of how distance ladder measurements actually work and, in particular, by the inappropriate use of a distance ladder H0 prior. A dynamics-free inverse distance ladder shows that changes to late time physics are strongly constrained observationally and cannot resolve the discrepancy between…
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## References

SHOWING 1-10 OF 38 REFERENCES

• Physics
• 2021
A dark-energy which behaves as the cosmological constant until a sudden phantom transition at very-low redshift ($z 4$\sigma$disagreement between the local and high-redshift determinations of the • Physics • 2021 A rapid transition of the dark energy equation of state parameter$w$at a transition redshift$z_t z_t$to$w z_t$. Such a Late$w$Phantom Transition ($LwPT$) avoids the discontinuity of$H(z)$• Physics • 2020 We present an expanded sample of 75 Milky Way Cepheids with Hubble Space Telescope (HST) photometry and Gaia EDR3 parallaxes, which we use to recalibrate the extragalactic distance ladder and refine • Physics Nature • 2020 Improved cross-sections of the deuterium burning D(p,γ)3He reaction lead to BBN estimates of the baryon density at the 1.6 percent level, in excellent agreement with a recent analysis of the cosmic microwave background. • Physics • 2020 We measure the anisotropic clustering of the quasar sample from Data Release 16 (DR16) of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey (eBOSS). A sample of • Physics • 2020 Late times dark energy transitions at redshifts$z \ll 0.1$can raise the predicted value of the Hubble constant to the SH0ES value,$74.03\pm 1.42$(km s$^{-1}$Mpc$^{-1})$or more, while providing • Physics • 2020 We revisit the observational constraints on spatial curvature following recent claims that the Planck data favour a closed Universe. We use a new and statistically powerful Planck likelihood to show • Physics The Astrophysical Journal • 2020 The observed tension (∼9% difference) between the local distance ladder measurement of the Hubble constant, H0, and its value inferred from the cosmic microwave background could hint at new, exotic, • Physics • 2020 Measurements of the Hubble constant and, more generally, measurements of the expansion rate and distances over the interval$0lzl1\$ appear to be inconsistent with the predictions of the standard
• Physics
The Astrophysical Journal
• 2019
NGC 4258 is a critical galaxy for establishing the extragalactic distance scale and estimating the Hubble constant ( ). Water masers in the nucleus of the galaxy orbit about its supermassive black