Small black holes may have had a huge impact on the early universe.
A large population is small black holes It would have flooded the young universe with particles and radiation, creating black holes of their own the great explosionthe physicists propose in a new paper.
To date, there is only one sure way to make black holes. You must start with a file a star Then let it die. Towards the end of his life, his core collapses under his own weight. With no other force capable of withstanding this pressure, it continues to collapse down to a tiny point: the singularity. Astronomers believe that this is the method used by all black holes in the universe, from the stellar-mass ones that populate every galaxy to supermassive black holes Which is located in the heart of the galaxy, started.
Related: How did cosmic inflation happen – and why should we care?
But there may be another way. The early universe was chaotic and lively, especially beyond economic inflationthe supposed event that triggered a spectacular expansion event that swelled the universe to gigantic sizes in less than a second.
When the inflation ended, space-time itself shook and vibrated as pent-up energies were released. Perhaps the universe has become so violent that random pockets of space-time can spontaneously reach critical thresholds in density and volume, leading to the formation of “primordial” black holes that engulfed the universe.
Astronomers have spent decades searching for these primordial black holes, which he originally proposed Stephen Hawking, or at least rule out the possibility of that happening. Countless observations declared an empty search, as any black holes larger than about a billion grams (about the mass of a typical mountain on Earth) would influence the subsequent evolution of the universe and violate known observations.
Development stopped
But not many researchers paid attention to the smaller black holes that can form in the wake of inflation. So a team of physicists has examined in detail how these smaller black holes might behave — and how we can detect them. They detailed their findings in a paper published on an online preprint database arXiv (Opens in a new tab).
All black holes have finite lives. Thanks to Hawking, we know that black holes are not entirely black. Instead, they slowly release radiation through a strange quantum process going on in them event prospects. This process, known as Hawking radiation, is very slow. A stellar-mass black hole emits only one particle of radiation each year. But smaller black holes release radiation at a faster rate. These smaller primordial black holes would not have lived long, as Hawking radiation would have caused them to evaporate in just a few minutes.
This was long before the next important era in The history of the universeformation of the first elements. So these black holes would have been able to escape the current observational limitations, because they would have left the scene early enough.
But we can still find ways to detect small primordial black holes, the researchers explain in their paper.
The most notable effect is that these black holes could have delayed the evolution of the universe. our The universe is always expanding. So after inflation, the density of matter and radiation decreased rapidly, as all that matter was diluted into an ever-increasing volume.
But primordial black holes could have prevented this paradigmatic evolution. Once formed, it would have started emitting Hawking radiation, converting its mass into radiation. Physicists have shown that these tiny black holes can add extra radiation as fast as the universe diluted it, thus keeping the density constant for the first few minutes after the Big Bang.
Related: Black holes in the universe (photos)
Primal instincts
This scenario would have put the universe into a kind of “stasis,” halting the universe’s normal expansion-driven evolution while black holes do their thing. The researchers discovered that this would have allowed black holes to have a number of effects on the universe without violating any known observations. They are born, do something interesting while the universe is at a standstill, and disappear, with the rest of cosmic history unfolding normally.
For example, the evaporation of these primordial black holes may be responsible for filling the universe with them dark matter or dark energy. Or, they may have triggered the process of pareogenesis, forcing the universe to do so More important than antimatter.
Primordial black holes can also infuse the universe with a unique signature gravitational waves, which are ripples in space-time. Current gravitational-wave detectors do not have the sensitivity to find these gravitational waves, but future space detectors–such as the Laser Interferometer Space Antenna, which is scheduled to be launched in the next decade–could.
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