Scientists have made one of the most accurate maps of the universe’s matter, and it shows that something might be missing in our best model of the universe.
Created by piecing together data from two telescopes that detect different types of light, the new map reveals that the universe is less “clumpy” than previous models predicted – a potential sign that the vast cosmic web connecting galaxies is not more well understood than scientists thought.
According to our current understanding, the cosmic web is a giant network of intersecting supercelestial roads paved with hydrogen gas and dark matter. It took shape in the chaotic aftermath that followed the great explosionThe web’s tendrils formed lumps of broth from the young universe. Where multiple strands of web intersect, galaxies eventually formed. But the new map, which was published on January 31st as three (Opens in a new tab) Separated (Opens in a new tab) studies (Opens in a new tab) In the journal Physical Review D, he shows that in many parts of the universe, matter is less lumped together and more evenly spread out than theory predicts it to be.
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“There appears to be a little less fluctuation in the current universe than we would expect assuming our standard cosmological model associated with the early universe,” co-author Eric Baxter, an astrophysicist at the University of Hawaii, said in a statement. he said in a statement (Opens in a new tab).
Spinning the cosmic web
According to the Standard Model of cosmology, the universe began to form after the Big Bang, when the young universe was filled with particles of both matter and antimatter, which came into existence only to annihilate each other upon contact. Most of the building blocks of the universe annihilated themselves in this way, but the rapidly expanding fabric of space-time, combined with some quantum fluctuations, meant that some pockets of primordial plasma remained here and there.
power gravity These pockets of plasma quickly compressed in on themselves, heating the material as they were squeezed so close together that sound waves traveling at half the speed of light (called acoustic baryon vibrations) ripple outwards from the plasma clumps. These ripples pushed matter that hadn’t already been drawn into the center of mass, where it settled as a halo around it. At that point, most of the universe’s matter was distributed as a series of thin films that surrounded the myriad cosmic voids, like a nest of soap bubbles in a sink.
Once this matter, primarily hydrogen and helium, cooled sufficiently, it coagulated further to give birth to the first stars, which in turn formed heavier and heavier elements through Nuclear fusion.
To map how the cosmic web is woven, the researchers combined observations taken with the Chile Dark Energy Survey — which surveyed the sky in the near-ultraviolet, visible, and near-infrared frequencies from 2013 to 2019 — and the Antarctic Telescope, which is located in Antarctica and studies Microwave emissions that make up the cosmic microwave background – the oldest light in the universe.
Although they look at different wavelengths of light, both telescopes use a technique called gravitational lensing to map the agglomeration of matter. Gravitational lensing occurs when a massive object sits between our telescopes and its source; The more distorted the light coming from a particular pocket of space, the more matter there is in that space. This makes gravitational lensing an excellent tool for tracking both normal matter and the mysterious dark matter, which although it makes up 85% of the universe, only interacts with light by distorting it with gravity.
With this approach, the researchers used data from both telescopes to locate matter and remove errors from one telescope’s data set by comparing it to the other telescopes.
“It works like a universal scan, so it becomes a more powerful measurement than if you just used one of them,” says the co-lead author Chihuai Chang (Opens in a new tab)University of Chicago astrophysicist said in the release.
The map of cosmic matter produced by the researchers is closely consistent with our understanding of how the universe evolved, except for a major discrepancy: It was more evenly distributed and less lumpy than the Standard Model of cosmology would suggest.
There are two possibilities to explain this discrepancy. The first is that we are simply looking at the universe very inaccurately, and the apparent deviation from the model will disappear as we get better tools for looking at the universe. The second possibility, and more important, is that our cosmological model is missing some very big physics. Figuring out which is correct will require further surveys and mapping, as well as a deeper understanding of the cosmological constraints that hold the soap suds together in the universe.
“There is no known physical explanation for this discrepancy,” the researchers wrote in one study. “The cross-correlation between the surveys… will enable significantly more robust cross-correlation studies that will provide some more precise and accurate cosmological constraints, and which will allow us to continue stress testing.” [standard cosmological] Model.”