The Expansion of the Universe is Faster than Expected
Adam G. Riess
(Submitted on 10 Jan 2020)
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. We review key advances realized by 2019:
— The local or late Universe measurement of the Hubble constant improved from 10% uncertainty twenty years ago to under 2% by the end of 2019.
— In 2019, multiple independent teams presented measurements with different methods and different calibrations to produce consistent results.
— These late Universe estimations disagree at 4σ to 6σ with predictions made from the Cosmic Microwave Background in conjunction with the standard cosmological model, a disagreement that is hard to explain or ignore.
Comments: Published Nature Reviews Physics, Year In Review, 2019, January 2020
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Journal reference: Nat Rev Phys 2, 10-12,2020
DOI: 10.1038/s42254-019-0137-0
Cite as: arXiv:2001.03624 [astro-ph.CO] (or arXiv:2001.03624v1 [astro-ph.CO] for this version)
Submission history
From: Adam G. Riess
[v1] Fri, 10 Jan 2020 19:00:06 UTC (720 KB)
