An Etymological Dictionary of Astronomy and Astrophysics

The discrepancy between the value of the → Hubble-Lemaitre constant inferred from a ΛCDM fit (→ Lambda cold dark matter model) to the → cosmic microwave background (CMB) and local measurements. The Universe appears to be expanding much faster now than predicted even with our latest understanding of its initial conditions and contents. Based on the → Hubble Space Telescope observations, the Hubble-Lemaitre constant is very recently estimated to be 74.03 km s^-1 Mpc^-1. This value indicates that the Universe is expanding at a rate about 9% faster than that implied by the → Planck satellite’s observations of the → early Universe, which give a value for the Hubble constant of 67.4 km s^-1 Mpc^-1. For discussion, see D’Arcy Kenworthy et al. (2019, ApJ 875, 145).

See also: → Hubble-Lamaitre constant; → tension.