Home » News & Blogs » Much Ado around Nothing: The Cosmological non-Constant Problem
Bookmark and Share
Backreaction

Much Ado around Nothing: The Cosmological non-Constant Problem

5 Feb 2016, 13:25 UTC
Much Ado around Nothing: The Cosmological non-Constant Problem
(200 words excerpt, click title or image to see full post)

Tl;dr: Researchers put forward a theoretical argument that new physics must appear at energies much lower than commonly thought, barely beyond the reach of the LHC.The cosmological constant is the worst-ever prediction of quantum field theory, infamously off by 120 orders of magnitude. And as if that wasn’t embarrassing enough, this gives rise to, not one, but three problems: Why is the measured cosmological constant neither 1) huge nor 2) zero, and 3) Why didn’t this occur to us a billion years earlier? With that, you’d think that physicists have their hands full getting zeroes arranged correctly. But Niayesh Afshordi and Elliot Nelson just added to our worries. In a paper that made it third place of this year’s Buchalter Cosmology Prize, Afshordi and Nelson pointed out that the cosmological constant, if it arises from the vacuum energy of matter fields, should be subject to quantum fluctuations. And these fluctuations around the average are still large even if you have managed to get the constant itself to be small.The cosmological constant, thus, is not actually constant. And since matter curves space-time, the matter fluctuations lead to space-time fluctuations – which can screw with our cosmological models. Afshordi and Nelson dubbed ...

Latest Vodcast

Latest Podcast

Advertise PTTU

NASA Picture of the Day

Astronomy Picture of the Day

astronomy_pod