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The Hubble Space Telescope captured an image of the galaxy cluster Cl0024+1654, revealing tiny red dots representing stars set against a backdrop of dark, bluish-hued matter.
After the Big Bang, the universe is widely believed to have experienced rapid expansion called inflation in its early stages. The origin of inflation remains a mystery, yet it must account for several observations, including the universe’s remarkably uniform flatness on a large scale.
Scientists believe that inflation was powered by an unusual quantum field, a fundamental entity present throughout spacetime. As inflation concludes, this field disintegrates into a cascade of particles and radiation, initiating the “hot Big Bang” that is commonly associated with the universe’s origin. These particles eventually combine to form the first atoms roughly 12 minutes after the universe’s birth and, after hundreds of millions of years, come together to create stars and galaxies.
Nonetheless, there is another element in the cosmic composition: dark matter. Once more, astronomers remain uncertain about the precise nature of dark matter, but they confirm its presence by observing its gravitational effects on ordinary matter.
Scientists did not find any evidence of dark matter’s existence until much later in the universe’s evolution when this elusive substance had enough time to exert its gravitational effects, so it didn’t necessarily have to fill the universe during the hot Big Bang along with ordinary matter. Moreover, because dark matter doesn’t interact with ordinary matter, it could have its own dark Big Bang, researchers argue.
Dark Big Bang
In their study, scientists delved into the concept of a “dark Big Bang.” Initially, they proposed the existence of a novel quantum field, referred to as the “dark field,” which would be crucial for the independent formation of dark matter.
Under this fresh perspective, the dark Big Bang would take place only after the cessation of inflation, when the universe has expanded and cooled adequately for the dark field to undergo a phase transition, leading to the emergence of dark matter particles.
Researchers found that the dark Big Bang must adhere to certain constraints. If it happened too early, there would be too much dark matter today, and if it occurred too late, there would be too little. But if the dark Big Bang occurred when the universe was less than a month old, it could potentially match all known observations.
Crucially, scientists have ascertained that a dark Big Bang would imprint a unique pattern in gravitational waves, the undulations in the fabric of spacetime that persistently traverse the cosmos. This revelation suggests the possibility of testing the theory in the future.