Scientists have long been puzzled by one of the biggest mysteries in the universe: dark matter.
Now, a new study suggests that gravitational waves—tiny ripples in space itself—may have played a key role in creating it shortly after the universe began.
The research, led by Professor Joachim Kopp from Johannes Gutenberg University Mainz and Dr. Azadeh Maleknejad from Swansea University, proposes a completely new way that dark matter could have formed.
Their findings were published in Physical Review Letters.
To understand the importance of this idea, it helps to know what dark matter is. Everything we can see—planets, stars, and even our own bodies—is made of ordinary matter. But this visible matter makes up only about 4% of the universe.
A much larger portion, around 23%, is believed to be dark matter, an invisible substance that does not emit light but has a strong gravitational pull. It helps shape galaxies and holds large cosmic structures together.
Despite its importance, scientists still don’t know what dark matter is made of. Many experiments around the world are trying to detect it, but so far, its particles have remained hidden.
The new study explores an unusual idea involving gravitational waves. These waves are ripples in spacetime that travel across the universe. They are usually produced by dramatic events such as collisions between black holes or neutron stars. However, there is also a type called stochastic gravitational waves, which form a faint background noise made up of waves from many different sources.
Some of these waves are thought to be extremely ancient, dating back to the earliest moments after the Big Bang. During this time, the universe was incredibly hot and dense, and it went through rapid changes as it expanded and cooled. These changes, known as phase transitions, could have generated large amounts of gravitational waves.
Kopp and Maleknejad suggest that these early gravitational waves might have done more than just travel through space. According to their calculations, some of their energy could have been converted into particles. Specifically, they may have produced very light particles known as fermions. Fermions are a basic type of particle that includes familiar examples like electrons and protons.
In the early universe, these fermions may have had little or no mass. Over time, as the universe evolved, they could have gained mass and become the dark matter particles we observe indirectly today.
This idea offers a completely new mechanism for how dark matter might have formed, one that scientists had not seriously explored before. While the theory is still in its early stages, it opens up exciting possibilities for future research.
The next step for the researchers is to refine their calculations using more detailed computer simulations. They also plan to investigate whether gravitational waves could explain other cosmic mysteries, such as why there is more matter than antimatter in the universe.
Although many questions remain, this study provides a fresh perspective on one of science’s greatest puzzles. It suggests that the faint echoes of the universe’s earliest moments may still hold the key to understanding the invisible matter that surrounds us today.
Source: KSR.
