The expansion of the Universe is faster than expected

By A. Riess. 2020

383 citations recorded by the source corpus.

The present rate of the expansion of our Universe, the Hubble constant, can be predicted from the cosmological model using measurements of the early Universe, or more directly measured from the late Universe. But as these measurements improved, a surprising disagreement between the two appeared. In 2019, a number of independent measurements of the late Universe using different methods and data provided consistent results, making the discrepancy with the early Universe predictions increasingly hard to ignore. The Hubble constant can be estimated from measurements of both the early and late Universe, but the two estimates disagree. In 2019 a number of independent measurements using different methods made this discrepancy harder to ignore. The local or late Universe measurement of the Hubble constant improved from 10% uncertainty 20 years ago to less than 2% by 2019. In 2019, multiple independent teams presented measurements with different methods and different calibrations to produce consistent results. These late Universe estimations disagree at 4 $$\sigma $$ σ to 6 $$\sigma $$ σ with predictions made from the cosmic microwave background in conjunction with the standard cosmological model, a disagreement that is hard to explain or ignore.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/52ee345c03f0492d1e87e4fb5dbbaebd3112b52a

How researchers see this paper

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In Astronomy and Astrophysics

1. Mikhail Ivanov
2. O. Philcox
3. M. Simonovi'c
4. M. Zaldarriaga
5. L. Senatore
6. Z. Vlah
7. Guido D'Amico
8. M. White

In Nuclear and High Energy Physics

1. Mikhail Ivanov
2. O. Philcox
3. M. Simonovi'c
4. M. Zaldarriaga
5. L. Senatore
6. Guido D'Amico
7. Pierre Zhang
8. S. Furlanetto

Citations in the corpus

• Combining full-shape and BAO analyses of galaxy power spectra: a 1.6% CMB-independent constraint on H0 (2020, background): “[2, 3]), are not in agreement, leading some to claim the existence of a ‘tension’ between the early- and late-Universe, prompting a swathe of new physics to be invented (see Ref.”
• Cosmology Intertwined II: The Hubble Constant Tension (2020, neutral): “[38] A.”