Scientists have discovered that matter makes up 31% of the universe’s total matter and energy, leaving dark energy to dominate the rest. This discovery was made by an international team of scientists, including researchers from Chiba University.
As reported in The Astrophysical Journal, a study conducted by the above team reveals that matter makes up 31% of the total matter and energy composition of the Universe. This finding highlights the dominant influence of dark energy on the character of the Universe.
Lead author of the study, Dr Mohammed Abdullah from the National Research Institute of Astronomy and Geophysics of Egypt and Chiba University in Japan, notes: “While about 20% of the total matter in the Universe is what we call ‘baryonic’ (including stars, galaxies, atoms and even life), 80% is dark matter.” These new results highlight the mystery and complexity of dark matter, which may be made up of as-yet undiscovered subatomic particles.
Study co-author and senior scientist Gillian Wilson of the University of California, Merced, reveals a key method of the study: “We estimated the number and mass of galaxy clusters in a given volume and compared that with simulations.”
The frequency of galaxy clusters in the modern Universe, or “cluster abundance”, provides valuable information about the material content of the Universe.
Anatoly Klypin from the University of Virginia adds: “A universe richer in matter would naturally have more clusters. However, measuring the mass of a galaxy cluster is difficult due to the invisible nature of much of the dark matter it contains.”
To solve this problem, the team turned to an innovative approach – counting galaxies inside clusters. More galaxies indicate a heavier cluster. Using data from the Sloan Digital Sky Survey, they estimated the total mass of each cluster, ultimately comparing their observations with modeling predictions .
The 31% composition of the substance they accurately determined is strikingly consistent with data from the Planck satellite, which used a completely different method. This confirms the accuracy and significance of their research.
Tomoaki Ishiyama of Chiba University notes, “We have successfully correlated our MRR measurements of matter density with data obtained from the CMB method by Planck’s team.” This synergistic approach resulted in more accurate results.
The team’s breakthrough also involves the use of spectroscopy, a technique that clearly identifies emission spectra, allowing precise determination of distances to clusters and identification of the true galaxies associated with them. Past attempts to use the MRR method have been less precise, often relying on basic imaging.
