Scientists accurately measure the total amount of matter in the universe

Accurately measuring the total amount of matter in the universe is one of the main goals of cosmology, even the most proficient in mathematics. A team led by scientists at the University of California, Riverside, has now done just that.

Reported in Astrophysical Journal, The team determined that 31% of the total amount of matter and energy in the universe is made up of matter, the rest is dark energy.

In the first context, Mohammed Abdullah said, “In context, if all the matter in the universe were spread evenly throughout space, it would be about six hydrogen atoms per cubic meter equal to the average mass density.” Graduate student in the UCR department of physics and astronomy. “However, we know that 80% of matter is really a dark matter. In fact, most of these substances contain not a hydrogen atom but a type of matter that cosmologists have not yet understood.”

Abdullah explained that a well-proven technique for determining the total amount of matter in the universe is to compare the observed number of galaxy clusters per unit volume and the predictions of numerical simulations of the mass. Because galaxy clusters are made up of billions of years of broken matter under their own gravity, the number of clusters observed at the present time is very sensitive to cosmological conditions and, in particular, the total amount of matter.

“The said high percentage of the substance will result in more clusters,” Abdullah said. “The ‘Goldilocks’ challenge for our team was to measure the number of clusters and then decide if ‘the answer is correct.’ But it is difficult to accurately measure the mass of any galaxy cluster because most of the matter is obscure so we cannot see it through binoculars. “

To overcome this difficulty, a team of astronomers led by UCR developed the first, “Galweight”, a global instrument to measure the mass of a galaxy cluster, using the orbits of its member galaxies. The researchers then used their tool for observations of the Sloan Digital Sky Survey (SDSS) to create a publicly available list of galaxy clusters “GWWTBT.19”. Finally, they compared the number of clusters in their new list with simulations to determine the total amount of matter in the universe.

“We’ve succeeded in one of the most accurate measurements we’ve ever made using galaxy cluster technology,” said Gillian Wilson, UCR’s professor of physics and astronomy, in whose laboratory Abdullah works. “Moreover, this is the first use of Galaxy Orbit technology that has gained value in agreement with teams obtained by people who used cosmic microwave background anasotropies, barion acoustic oscillations, type IA supernova or gravitational lensing technology.”

Anatoly Klippin, a third co-expert in statistical simulations and cosmology, said: “The big advantage of using our Galvite Galaxy Orbit technology was that our team was able to determine the group individually for each cluster rather than relying on more classic, statistical methods. “.

Combining their measurements with those of other teams using different techniques, the UCR-led team was able to determine the best combined value, concluding that the matter is 31.5 ± 1.3% of the total amount of matter and energy radiation in the universe.

This research paper is named “Cosmological Contraindications from Ω M Ω M and σ8 Cluster Abrands using GWHT.19 Optical-Spectroscopic SDSS Catalog.”