a different kind of multiverse
There are different versions of the “Multiverse”. The most popular model—that of the Marvel Cinematic Universe—proposes that there are as many universes as there are possibilities and that these versions of reality are parallel. Physics proposes something much calmer and mathematically consistent: cosmic buoyancy.
In this model, the universe is not born from a singularity, but rather expands, contracts, and expands again in an endless cycle. Each “universe” is not parallel, but sequential – that is, one arises from the ashes of the previous one.
Is it possible for something to survive to the end of its universe and continue into the next universe? According to a paper published in Physical Review D, yes. Author Enrique Gaztanaga, a research professor at the Institute of Space Sciences in Barcelona, explains that any structure larger than about 90 meters could undergo the final collapse of the universe and survive the rebound. These “relics” will not only persist, but may also seed the formation of giant, unexplained structures seen in the early stages of the present universe. Moreover, they may be the key to understanding dark matter.
For decades, the leading explanation for dark matter has been that it is an unknown particle or particles. But after years of experiments without direct detection, physicists have begun to look for alternatives. One of them proposes that dark matter is not some exotic particle, but an abundant population of tiny black holes that we ignore.
The idea is attractive, but it has a serious problem. For these black holes to explain dark matter, they would have to exist from the earliest moments of the universe, long before the first stars collapsed. There are indications that these objects may exist, but a solid physical mechanism to explain their origin is lacking.
A universe born with a black hole
This is where Gaztanaga’s newly proposed model shines. If cosmic buoyancy allows compact structures to survive the collapse of the previous universe, the present universe would have been born with black holes already present. They would not have arisen from extreme fluctuations or microinflationary processes, but would have been present from the very first moment.
This notion has the potential to solve two puzzles simultaneously: the origin of black holes and the nature of dark matter. If this model is correct, then dark matter would not be a mystery of the early universe but a legacy of a universe that predates ours.
“Much work remains to be done,” Gaztanaga, a researcher at the Institute of Cosmology and Gravitation at the University of Portsmouth, said in an article for The Conversation. “These ideas must be tested against data ranging from the gravitational-wave background to galaxy surveys and precise measurements of the cosmic microwave background.”
“But the potential is much deeper,” he said. “The universe may not have begun once, but it may have come into existence again. And the dark structures shaping galaxies today may be remnants of a time before the Big Bang.”
This story originally appeared Wired in Español and translated from Spanish.
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