Dark matter map hints at cracks in our understanding of the universe

 The distribution of matter within the universe is also 10 percent smoother than thought, potentially upending our understanding of the evolution of the cosmos.

Today, scientists announced results from the seven-year Kilo-Degree Survey (KiDS), using the Very Large Telescope (VLT) at the ECU Southern Observatory in Chile to look at quite 30 million galaxies within the universe up to 10 billion light-years from Earth. Those results reaffirm previous indications about the spread of substance.

“The universe appears to be less clumpy than our greatest theory of the universe at the instant would suggest,” says Catherine Heymans at the University of Edinburgh, UK, the study’s lead author. “It [would] mean there’s more to grasp out there.”

Following the massive bang 13.7 billion years ago, our universe went through a period of inflation and expansion, relinquishing remnant heat within the process that we will observe today – the cosmic microwave background (CMB) – which shows us the spread of matter throughout the universe.

However, a spread of matter studies over the past few years have begun to indicate a discrepancy between the CMB and also the measured distribution of substance, which makes up about 85 percent of the mass of the universe. the youngster's results find further evidence for that discrepancy.

Map showing the spread of substance

B.Giblin, K. Kuijken and therefore the KiDS team

The survey examined the sunshine bent, or lensed, by the gravitational pull of the matter in about five percent of the universe as seen from Earth. This was combined with observations of the clustering of galaxies from a separate survey, called the Baryon Oscillation Spectroscopic Survey (BOSS), to supply an accurate measurement of the spread of matter.

While other surveys have also conducted similar research, this latest study was noticeable for its level of accuracy, says Alan Heavens at Imperial College London. “They are the foremost precise [results] that are published thus far,” he says.

If the findings are correct, they might have some broad implications. It could mean that gravity on large scales is different than thought, with the speed at which matter falls into dense regions of the universe, as predicted by Einstein’s theory of relativity theory, slower than predicted. Or it may be that our understanding of dark energy, thought to be the motive force behind the accelerated expansion of the universe, is much from complete.

“This quite discrepancy wasn't expected from our physical model of the universe,” says Elisabeth Krause at the University of Arizona. “The jury’s still out whether there's any evidence within the follow-up systematic effects we've got to model, or if this can be actual new fundamental physics.”

Further surveys are underway, as the international Dark Energy Survey, to supply more data on these results. And not everyone seems to be convinced about the findings just yet. “It’s one among those tantalizing results that are not enough on its own to mention we'd like to overthrow everything,” says Heavens.

But if results from other surveys suggest an identical smoothness to substance, it may be the beginning of some interesting new physics. “It’s another crack within the model,” says Heymans. “It’s still thereon fringe of beginning to feel uncomfortable.”