Universe accelerated beyond the horizon

As I was trying to keep myself busy with modifications of general relativity, I came across to the new paper of the famous cosmologist Kolb and colleagues. They claim that inflation today is created by the primordial fluctuations stretched beyond the horizon. Approach is extremely conservative and the final diagram is very impressive. My first intuition about the super-Hubble modes is that they are just flat ground states here inside the horizon, but this is not enough to drive acceleration it has to dilute much slower than matter. The statistical reason for that is not crystal clear to me, but may be I shouldn’t feel bad because it even puzzled Sean Carroll. He thinks that nothing beyond the horizon can influence us.

For the records, I should say that I did not like the proposed solution. We always thought that solution of the acceleration of the universe puzzle will also solve two other great mysteries. Namely; why we do not see a cosmological constant in the Einstein-Hilbert action although the known symmetry principles allow it, and why the QFT vacuum condensates (ground state) do not gravitate; or why they cancel out. If the acceleration is due to super-Hubble fluctuations, I think we will be in a worse trouble. At least they are offering observable differences from a pure cosmological constant and nature will say the last word.