An analysis of more than 70,000 galaxies by University of California, Berkeley, University of Zurich and Princeton University physicists demonstrates that the universe – at least up to a distance of 3.5 billion light years from Earth – plays by the rules set out 95 years ago by Albert Einstein in his General Theory of Relativity.

The research was published in the 11 March issue of the journal Nature, and former ICTP Diploma student Reinabelle Reyes (now a Princeton University graduate student) is the first author. Among the other authors is Uros Seljak, an astrophysics professor at the University of California - Berkeley who was a scientist with ICTP's High Energy Physics section from 2004 until 2006.

By calculating the clustering of these galaxies and analyzing their velocities and distortion from intervening material, the researchers have shown that Einstein's theory explains the nearby universe better than alternative theories of gravity. One major implication of the new study is that the existence of dark matter is the most likely explanation for the observation that galaxies and galaxy clusters move as if under the influence of some unseen mass, in addition to the stars astronomers observe.

The title of the paper is "Confirmation of general relativity on large scales from weak lensing and galaxy velocities".

Adapted from materials provided by University of California - Berkeley.