It turns out that the geometry of the universe is so complex that previous methods cannot determine its shape
There are theories about the structure of the universe, such as 'an open universe that continues to expand,' 'a closed universe that continues to contract,' and 'a flat universe that neither expands nor contracts,' and it is not clear which theory is correct. In April 2024, the international research team 'COMPACT Collaboration' announced the results of their research, which states that 'the structure of the universe may be more complex than previously thought.'
Phys. Rev. Lett. 132, 171501 (2024) - Promise of Future Searches for Cosmic Topology
Physics - The Universe's Topology May Not Be Simple
https://physics.aps.org/articles/v17/74
The universe may have a complex geometry — like a doughnut
https://www.sciencenews.org/article/universe-geometry-doughnut-physics
It is known that the universe expanded rapidly after its birth in the Big Bang. Regarding the future of the universe, which continues to expand after that, there are the 'open universe' theory, which says that it will continue to expand infinitely, the 'closed universe' theory, which says that it will expand to a certain mass and then contract, and the 'flat universe' theory, which says that even after the mass of the universe reaches a certain level, it will not begin to contract and will maintain its size.
Meanwhile, the overall picture of the universe is thought to have been determined by quantum processes at the moment of the Big Bang, that is, the formation of structures at levels smaller than the size of an atom. In other words, if we can determine the shape of the universe, or its topology, we can gain important insights into what the early universe was like, so researchers are observing the universe to find clues to this.
One of the most important aspects of research into the topology of the universe is the cosmic microwave background radiation (CMB), a photon emitted 380,000 years after the birth of the universe. The CMB is also known as the 'embers of the Big Bang,' and it is believed that observing the CMB can help us infer the structure of the universe. In 2018, the European Space Agency (ESA) released detailed observational data from the CMB observation satellite ' Planck .' It was hoped that this would advance our understanding of the structure of the universe.
One of the leading theories about the topology of the universe is that the universe has a torus structure. Simply put, a torus structure is a doughnut-shaped structure that has loops in all directions, like an old RPG. If the universe had a torus structure, there should be multiple points in the CMB observational data that have exactly the same CMB characteristics, but even large-scale observational projects like the Planck project have not found any such data.
There are many structures in which closed loops can exist, including not only simple torus structures but also structures such as 'structures in which a rectangular parallelepiped is twisted into a loop.' In this study, we looked at 17 types of structures in which closed loops can exist, and examined the possibility that the universe can fit each structure. As a result, we found that if the universe has a complex loop structure, the same region of the universe will look different after the loop. In other words, the conventional method of searching for 'points with exactly the same CMB characteristics' may miss the loop structure.
The research team says they will continue to analyze the loop structure in order to elucidate the topology of the universe.
Related Posts:
in Science, Posted by log1o_hf