7 February 2006 Most cosmologists believe that the universe is
dominated by “dark energy” — a mysterious form of energy that
could explain why the universe is expanding and accelerating at
the same time. Now, however, theoretical physicists have studied
a new model of gravity that can, they claim, account for the
acceleration of the universe without any need for dark energy.
Their model relies instead on modifications to the way that
gravity behaves at ultra-large cosmological distances (Phys.
Rev. Lett. 96 041103).