A paper appeared on the arXiv last night entitled Primordial Inflation Explains Why the Universe is Accelerating Today by Rocky Kolb of Fermilab, together with Sabino Matarrese, Alessio Notari and Antonio Riotto. There’s also a Fermilab press release about it today.
I’m no expert on the subject, and would love to hear the opinion of someone who is. As near as I can figure out the idea is that what is really responsible for the effects that have been ascribed to a cosmological constant is a “cosmological perturbation” of the gravitational field. This is supposed to be a perturbation that expanded during the inflationary period so that its wavelength is now larger than the Hubble radius. According to the authors, this predicts a different magnitude vs. red-shift relation than the standard cosmological constant does, so their idea should in principle be testable.
If they’re right, this certainly will cause a huge problem for the whole “Landscape” business, which has advertised as its greatest success the “prediction” of a non-zero cosmological constant of the right order of magnitude.