Contradiction to theory of relativity: Cosmic gravitational sinks get flatter
Massive galaxies may now be distorting space-time less than predicted by the theory of relativity. Is Einstein about to be replaced?
(Image: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi)
As the universe ages, gigantic masses such as galaxies appear to distort space-time slightly less than they should according to Albert Einstein's theory of relativity. This is suggested by data from a giant sky survey, claims a research group led by Isaac Tutusaus from the University of Toulouse. They believe that the discovered phenomenon could be directly linked to the accelerated expansion of the universe. With a significance of 3 sigma, the discovery is not yet considered proven, with 5 sigma being the necessary limit. But it justifies further investigations, says the team.
Treacherous gravitational lenses
As the group recalls, Einstein's general theory of relativity suggests that the universe can be imagined as a kind of bed sheet. This then represents space-time, in which massive bodies create depressions in which, for example, light is bent. The more massive the objects, the deeper these depressions. Exactly how deep can be calculated using the theory and the group has now verified this using data from the Dark Energy Survey. Using gravitational lensing, they have determined how deep the gravitational sinks were in 100 million galaxies three and a half, five, six and seven billion years ago.
The analysis showed that the gravitational sinks six and seven billion years ago would have corresponded to the theoretical predictions. "Closer to today – 3.5 and 5 billion years ago – however, they are somewhat shallower than Einstein predicted," Tutusaus summarizes the discovery. At the same time, this is precisely the epoch in the history of the cosmos in which the accelerated expansion began. It is possible that the explanation for both phenomena is the same: gravity could work differently on a cosmic scale than Einstein predicted. The study has now been presented in the journal Nature Communications.
Measurement data or theories that contradict Einstein's theory of relativity are sometimes presented, but so far it has proved resistant. The Dark Energy Survey used for the latest experiment is actually intended to find structures that are invisible to us by precisely mapping visible objects and thus contribute to research into the mysterious dark energy. After all, "normal" matter only makes up around five percent of the universe, dark matter another 25 percent and dark energy the remaining 70 percent. Until now, the data had largely confirmed the so-called standard model of cosmology. Tutusau's team now wants to test its own assertion using data from the Euclid space telescope.
(mho)