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

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


The Very Large Telescope in the Chilean Atacama desert

ESO/F. Kamphues

The distribution of dark matter in the universe could also be 10 per cent smoother than thought, probably upending our understanding of the evolution of the cosmos.

Today, scientists introduced outcomes from the seven-year Kilo-Degree Survey (KiDS), utilizing the Very Large Telescope (VLT) at the European Southern Observatory in Chile to look at greater than 30 million galaxies in the universe as much as 10 billion gentle years from Earth. Those outcomes reaffirm earlier indications about the unfold of darkish matter.

“The universe appears to be less clumpy than our best theory of the universe at the moment would suggest,” says Catherine Heymans at the University of Edinburgh, UK, the research’s lead writer. “It [would] mean there’s more to understand out there.”

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Following the large bang 13.7 billion years in the past, our universe went by way of a interval of inflation and enlargement, abandoning remnant warmth in the course of that we will observe right this moment – the cosmic microwave background (CMB) – which reveals us the unfold of matter all through the universe.

However, a spread of darkish matter research over the previous few years have begun to indicate a discrepancy between the CMB and the measured distribution of darkish matter, which makes up about 85 per cent of the mass of the universe. The KiDS outcomes discover additional proof for that discrepancy.

massmap

Map displaying the unfold of darkish matter

The survey examined the gentle bent, or lensed, by the gravitational pull of darkish matter in about 5 per cent of the universe as seen from Earth. This was mixed with observations of the clustering of galaxies from a separate survey, known as the Baryon Oscillation Spectroscopic Survey (BOSS), to supply an correct measurement of the unfold of darkish matter.

While different surveys have additionally performed comparable analysis, this newest research was noticeable for its stage of accuracy, says Alan Heavens at Imperial College London. “They are the most precise [results] that have been published so far,” he says.

If the findings are right, they might have some broad implications. It might imply that gravity on giant scales is totally different than thought, with the fee at which matter falls into dense areas of the universe, as predicted by Einstein’s principle of common relativity, slower than predicted. Or it could possibly be that our understanding of dark energy, regarded as the driver behind the accelerated enlargement of the universe, is way from full.

“This kind of discrepancy was not expected from our physical model of the universe,” says Elisabeth Krause at the University of Arizona. “The jury’s still out whether there is an explanation in the follow-up systematic effects we have to model, or if this is actual new fundamental physics.”

Further surveys are beneath method, equivalent to the worldwide Dark Energy Survey, to supply extra information on these outcomes. And not everyone seems to be satisfied about the findings simply but. “It’s one of those tantalising results that is not enough on its own to say we need to overthrow everything,” says Heavens.

But if outcomes from different surveys counsel an identical smoothness to darkish matter, it could possibly be the begin of some attention-grabbing new physics. “It’s another crack in the model,” says Heymans. “It’s still on that edge of starting to feel uncomfortable.”

Journal reference: Astronomy & Astrophysics, in press

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