Quote:In Einstein's relativity theory, space is a continuum. Oriti now breaks down this space into tiny elementary cells and applies the principles of quantum physics to them, thus to space itself and to the theory of relativity describing it. This is the unification idea.
A fundamental problem of all approaches to quantum gravity consists in bridging the huge dimensional scales from the space atoms to the dimensions of the universe. This is where Oriti, his colleague Lorenzo Sindoni and Steffen Gielen, a former postdoc at the AEI who is now a researcher at the Perimeter Institute in Canada, have succeeded. Their approach is based on so-called group field theory. This is closely related to loop quantum gravity, which the AEI has been developing for some time.
The task now consisted in describing how the space of the universe evolves from the elementary cells. Staying with the idea of fluids: How can the hydrodynamics for the flowing water be derived from a theory for the atoms?
This extremely demanding mathematical task recently led to a surprising success. "Under special assumptions, space is created from these building blocks, and evolves like an expanding universe," explains Oriti. "For the first time, we were thus able to derive the Friedmann equation directly as part of our complete theory of the structure of space," he adds. This fundamental equation, which describes the expanding universe, was derived by the Russian mathematician Alexander Friedman in the 1920s on the basis of the General Theory of Relativity. The scientists have therefore succeeded in bridging the gap from the microworld to the macroworld, and thus from quantum mechanics to the General Theory of Relativity: they show that space emerges as the condensate of these elementary cells and evolves into a universe which resembles our own.
Read more at: http://phys.org/news/2013-09-quantum-big.html#jCp
