Dark energy flips its sign, but the Hubble tension refuses to budge
For nearly a century, astronomers have known that the universe is expanding. In the late 1990s, two independent teams, the Supernova Cosmology Project, led by Saul Perlmutter, and the High-Z Supernova Search Team, led by Brian Schmidt and Adam Riess, discovered something strange: The expansion is sp...
Image: Phys.org
For nearly a century, astronomers have known that the universe is expanding. In the late 1990s, two independent teams, the Supernova Cosmology Project, led by Saul Perlmutter, and the High-Z Supernova Search Team, led by Brian Schmidt and Adam Riess, discovered something strange: The expansion is speeding up. The finding earned them the 2011 Nobel Prize in Physics. The leading explanation for this acceleration is "dark energy," a mysterious force usually modeled as a constant called Lambda, pushing space apart. Combined with cold dark matter, this gives us the LCDM model, the standard picture of the cosmos for the past 25 years.
Originally published at Phys.org
