Dark matter may be distributed smoother in the universe than thought, which could upend understanding of the evolution of the universe. Recently, scientists announced the results of a seven-year Millennium Survey (KiDS), which used the European Southern Observatory’s Very Large Telescope (VLT) in Chile to observe more than 30 million galaxies in the universe 10 billion light-years from Earth. The results showed that the cosmological uniformity was nearly 10% higher than predicted by the cosmological standard model.
The map shows the spread of dark matter. Photo credit: B.Giblin, K. Kuijken, et al.
The researchers have submitted the paper to Astronomy and Astrophysics.
Lead author of the study, Catherine Heymans of the University of Edinburgh, said: “The universe doesn’t look as clumped as we think our best theory of the universe suggests. That means there’s more to understand. “
After the Big Bang 13.7 billion years ago, the universe went through a period of expansion and left behind in the process, a process that can be observed today with cosmic microwave background radiation (CMB), which shows the spread of matter throughout the universe, New Scientist reported. However, various studies of dark matter over the past few years have shown a contradiction between CMB and dark matter distribution measurements, which account for about 85 percent of the mass of the universe. The KiDS findings provide further evidence for this discrepancy.
The study looked at the curved light that occurs in the universe under the gravitational pull of about 5% dark matter observed on Earth. This, combined with another separate study called the Heavy Suboscillation Spectroscopy Survey (BOSS), provides an accurate measurement of the spread of dark matter.
Alan Heavens, of Imperial College London, said that while similar studies had been conducted in other studies, the accuracy of the new study was remarkable. “This is the most accurate study ever published,” he said. “
If these findings are correct, they may have some wide-ranging implications. This could mean that gravity on a large scale is different from what one might think, and that, as Einstein’s general theory of relativity predicted, matter falls into dense regions of the universe more slowly than expected. Or, people’s understanding of dark energy is far from adequate. Dark energy is thought to be the driving force behind the universe’s accelerated expansion.
“Our model of the universe didn’t anticipate this difference, ” says Elizabeth Krause of the University of Arizona. One is not sure whether there is an explanation for the subsequent system effects, or whether this is a new physics theory. “
But not everyone believes in these findings. “It’s an enticing result, but it doesn’t in itself mean we need to overturn everything.” Heavens said.
However, if other surveys show similar smoothness in dark matter, this could be the beginning of a new physics.