When modern cosmologists began to tackle cosmic acceleration and dark energy, they dusted off Einstein’s cosmological constant as interchangeable with dark energy, given the new knowledge about cosmic acceleration.
“We set out to find the best explanation we could come up with for the anomalous acceleration of the galaxies within Einstein’s original theory without dark energy,” Temple said.
The original theory of General Relativity has given correct predictions in every other context, Temple said, and there is no direct evidence of dark energy.
So why add a “Fudge factor” to equations that already appear correct? Instead of faulty equations that need to be tweaked to get the right solution, the mathematicians argue that the equations are correct, but the assumption of a uniformly expanding universe of galaxies is wrong, with or without dark energy, because that configuration is unstable.
Temple, Smoller and Vogler worked out solutions to General Relativity without invoking dark energy. Remarkably, the local space-times created by the instability exhibit precisely the same range of cosmic accelerations as you get in theories of dark energy, he said.
The paper does include testable predictions that distinguish their model from dark energy models, Temple said.