Japanese scientists have developed a new model to explain some of the biggest mysteries of the universe: the disappearance of black holes and the possible existence of dark matter.
The results of this study were published in the peer-reviewed academic journal Physical Examination Letters.
If true, the results of this research will help paint a more complete picture of the early universe and the structure of the cosmos itself.
Cosmic enigmas: black holes, dark matter and the birth of the universe
This study deals with some very complicated and still poorly understood concepts in astrophysics, so let’s break it down one by one.
First, let’s start with the simplest: the universe itself.
The universe is estimated to be around 13.8 billion years old. Although it started out incredibly small, it has since exploded into the almost infinite expanses of space that we all know today. Since the Big Bang, the universe has evolved from this small singularity to a paradoxically animated but empty space, populated by stars, galaxies, and other structures while also exhibiting large amounts of emptiness.
But cosmic microwave background (CMB) radiation is also present in the universe. These are essentially the remains of the Big Bang itself, and they can be found everywhere.
Now let’s talk about dark matter.
To put it simply, we don’t know what dark matter is. We believe that dark matter is the impossible-to-see matter that exists throughout the universe, making the collective mass of everything in the universe much heavier than it appears.
In theory, dark matter is an invisible substance that does not emit any light and which constitutes more than 85% of the observable matter in the universe. The standard model of cosmology also states that it is vital to the continued evolution of the universe.
We only know that it exists – supposedly, because some researchers still debate it – because of gravity. Gravity as we know it is explained by Albert Einstein’s theory of general relativity. Anything that cannot be explained by this is generally thought to be due to the influence of dark matter.
However, some researchers have suggested another possible explanation for dark matter, and that’s our next topic: black holes.
Black holes are massive concentrations of gravity so strong that nothing, not even light, can escape, making them invisible. Like dark matter, the only way scientists could determine their existence was through gravity, and like dark matter, they play a key role in how the universe works.
However, unlike dark matter, which is so mysterious that some scientists question whether it even exists, black holes are a very well-established scientific fact. Most of them form when a large star dies, which plays a major role in the life cycle of stars and galaxies.
But the research also suggested that black holes don’t just form when stars die. Rather, they may have existed since the beginning of the universe.
These hypothetical black holes from the dawn of the universe are known as primordial black holes (PBHs), and they are believed to predate the birth of stars.
But in addition to solving many other mysteries, such as the James Webb Space Telescope’s discovery of massive galaxies in the early universe that should not have formed at that time, scientists also believe they can solve another mystery: dark matter.
Black holes are incredibly dense and heavy, so they could, in theory, help explain the extra mass in the universe attributed to dark matter. Plus, they could help explain other mysteries. But all this depends on one thing: there must be enough of them in the universe. And so far, scientists have failed to find them.
“Since the recent innovation of gravitational wave astronomy, binary black hole mergers have been discovered, which can be explained if PBHs exist in large numbers,” said graduate student Jason Kristiano. “But despite these strong reasons for their expected abundance, we haven’t seen any directly, and we now have a model that should explain why this is the case.”
Research into the formation of primordial black holes is problematic for the researchers behind the study. For example, the CMB does not seem to support the main proponents of the formation of these black holes.
So, faced with a model that seemed to conflict with established CMB data, the researchers did the only thing they could: they corrected the model to ensure it aligned with the data.
“At the beginning, the universe was incredibly small, much smaller than the size of a single atom. Cosmic inflation quickly increased this figure by 25 orders of magnitude. At that time, waves passing through this tiny space could have have relatively large amplitudes, but very “We found that these tiny but strong waves can result in an otherwise inexplicable amplification of much longer waves that we observe in the current CMB,” said Professor Jun’ichi Yokoyama, director of the Research Center for the Early Universe (RESCEU) and the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI) at the University of Tokyo.
“We believe this is due to occasional instances of coherence between these early short waves, which can be explained using quantum field theory, the most robust theory we have for describing everyday phenomena such as photons or electrons While individual short waves would be relatively powerless, coherent groups would have the power to reshape waves much larger than themselves. This is a rare case where a theory has something to do. an extreme scale seems to explain something at the opposite end of the scale.”
So we are dealing with wavelengths and fluctuations. The idea is rather complex, but to put it simply, small-scale fluctuations in the early universe actually impact larger fluctuations in the CMB. This is a big deal, but it’s important because it gives new implications for anything that relies on these kinds of wavelengths.
And it is precisely these short but strong wavelengths that would create the primordial black holes.
Overall, primordial black holes should still exist. But based on this new model, there wouldn’t need to be as many as previously thought.
But all this still remains theoretical. What is needed is real research to confirm this. Fortunately, a joint observation mission between the United States, Italy and Japan is doing just that: studying what are likely primordial black holes.
The results of this study will determine the accuracy of this model.