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Inspired by https://arxiv.org/abs/1907.10625 and several important observational updates in recent months, I put together an updated compilation plot of H0 measurements from indirect (cosmological-model-dependent) and direct methods. References are in the thread below. All units km/s/Mpc
Planck 2018: https://arxiv.org/abs/1807.06209 H0 = 67.36 +/- 0.54 This is derived from the CMB TT+TE+EE and CMB lensing power spectra. ("This value is our “best estimate” of H0 from Planck, assuming the base-LCDM cosmology." on their page 17)
ACT DR4 + WMAP9: https://arxiv.org/abs/2007.07288 H0 = 67.6 +/- 1.1 This is derived from the CMB TT+TE+EE power spectra, with a conservative prior on the optical depth tau. @ACT_Pol verifies that Planck 2018 'low' H0 value is not due to any systematics in CMB data.
WMAP9: https://arxiv.org/abs/1212.5225 H0 = 70.0 +/- 2.2 This is derived from the CMB TT+TE+EE power spectra. Included for historical completeness, and still impressive!
DES-Y1 + BAO + BBN: https://rb.gy/xwioxy (arxiv version is not up-to-date, hence MNRAS link) H0 = 67.4 +1.1 -1.2 No CMB needed: @theDESurvey combined with BAO (mostly BOSS), BBN, and COBE-FIRAS T0 yields H0 from the sound horizon scale in agreement with Planck, assuming LCDM.
BOSS-EFT + BBN: https://arxiv.org/abs/2002.04035 H0 = 68.6 +/- 1.1 No CMB needed: using EFT to model the full shape of the BOSS galaxy power spectrum combined with BAO, BBN, and COBE-FIRAS T0 yields H0 (from the sound horizon scale and P(k) shape) in agreement with Planck, assuming LCDM.
BOSS-EFT + Pantheon SNIa + Planck CMB lensing: https://arxiv.org/abs/2008.08084 H0 = 70.6 +3.7 -5.0 No sound horizon needed: combining uncalibrated (relative) SNIa distances with BOSS-EFT and CMB lensing yields H0 from the matter-radiation equality scale, but with large error bars.
Now for direct measurements, starting with SH0ES: https://arxiv.org/abs/1903.07603 H0 = 74.03 +/- 1.42 Inference from SNIa distances calibrated with Cepheids, themselves calibrated by combining LMC detached eclipsing binaries, masers in NGC 4258, and Milky Way parallaxes.
CCHP: https://arxiv.org/abs/2002.01550 H0 = 69.6 +/- 0.8 (stat) +/- 1.7 (syst) Inference from SNIa calibrated with tip-of-the-red-giant-branch (TRGB) distances, themselves calibrated with LMC detached eclipsing binaries (and other distance cross-checks, e.g., SMC DEBs).
TDCOSMO: https://arxiv.org/abs/2007.02941 H0 = 67.4 +4.1 -3.2 No distance ladder needed: Inference of H0 from strong gravitational lensing time delay distances. Important update of earlier H0LiCOW result, now with more conservative marginalization over lens mass profiles.
Megamasers: https://arxiv.org/abs/2010.01119 H0 = 69.0 +2.9 -2.8 No distance ladder needed: Inference of H0 from geometric megamaser distances (see https://arxiv.org/abs/2001.09213 ), but with updated modeling/marginalization over peculiar velocity corrections using 2M++ galaxy redshift data.
Surface brightness fluctuations (SBF): https://arxiv.org/abs/2008.07754 H0 = 70.50 +/- 2.37 (stat) +/- 3.38 (syst) Inference from SNIa calibrated with SBF-derived distances to 24 SN host galaxies, but with large error bars at present.
Mira variables: https://arxiv.org/abs/1908.10883 H0 = 73.3 +/- 4.0 Inference from SNIa calibrated with Mira variable distances to NGC 1559 and NGC 4258, along with megamaser and the LMC DEBs, but with fairly large error bars at present.
Comments/feedback welcome -- hopefully this is a useful guide to keep track of recent developments in this fast-moving subject. Please feel free to use in talks or elsewhere (with attribution) #H0tension #cosmology #CMB #Hubble
(I don't plan to add any analysis or interpretation to this thread, but feel free to do so.)
Also, if you're in the US, please vote!
Also, if you're in the US, please vote!
