Researchers at the Perimeter Institute have developed KiSS-SIDM, a computational tool that bridges intermediate regimes in a model of self-interacting dark matter, and may improve the understanding of core collapse and even the formation of black holes.
Credit: SciTechDaily.com
A new computational breakthrough is giving scientists a clear look at how dark matter evolves.
Dark matter, which has been one of the greatest mysteries in cosmology for nearly a century, shapes the universe and is still invisible and largely misunderstood. New research from the Perimeter Institute now presents a computational tool designed to track the evolution of a specific type of potential dark matter, called self-interacting dark matter halos. These vast structures are thought to host galaxies like the Milky Way.
The research expands scientists' ability to investigate how different types of interactions between dark matter particles affect the evolution and behavior of cosmic structures over time.
Self-interacting dark matter is defined by the ability of its particles to collide with each other, while remaining virtually invisible to ordinary baryonic matter, including photons, neutrons, and electrons. This behavior has important implications for dark matter halos, which many theorists believe play a central role in the processes that shape galaxies and trigger star formation.
"Dark matter forms relatively diffuse clumps that are still much denser than the average density of the universe," says James Gurian, of the Perimeter Institute. "The Milky Way and other galaxies reside in these dark matter halos."
Gravitational-thermal collapse and the evolution of halos
The evolution of self-interacting dark matter halos is governed by a phenomenon called gravitational-thermal collapse. This process arises from a counterintuitive property of gravity, in which gravitationally bound systems heat up, rather than cool down, as they lose energy.
Self-interacting dark matter can carry energy through particle collisions, so this energy gradually flows outward within the halo. As a result, the central region becomes increasingly hot and dense, causing further changes in the halo's structure over time.
To map the structures created by self-interacting dark matter, scientists typically take one approach when the dark matter is less dense with less frequent collisions, and another approach when the dark matter is denser with more frequent collisions—but they haven’t had a mapping approach for intermediate properties. Gurian and co-author Simon May have developed a code, KISS-SIDM, that is faster and more accurate than previous codes and is available to the scientific community.
Implications for the formation of black holes
Understanding core collapse has also intrigued physicists because it could have observable implications for the formation of black holes. But the details of how the process ends are an open question in physics, and the code is a step toward the answer.
“The fundamental question is what is the ultimate endpoint of this collapse? That’s what we really want to do – study the stage after a black hole is formed,” says Gurian.
More of the topic in Hayadan:
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Avinoam, remember – only one comment per article. The rest will be deleted.
Best regards
Avi Blizovsky
There is no tangible physical thing that can be called dark matter. Matter is a tangible physical thing that can be touched, and it has the energy of levitation. This type of energy can be distinguished with a simple experiment, which is the bucket-full-of-water experiment. We will tie a spring to the handle of a bucket full of water, and try to lift the bucket with this spring.
It immediately becomes clear to us that the bucket filled with water does not rise immediately, but only after it has been stretched to a certain length, during which it remains in place and does not move upward. This action of exerting effort, in stretching the spring – without moving upward, required the experimenter to expend a quantity of energy, and this is the buoyancy energy of the bucket filled with water.
Amounts of buoyancy energy can be easily measured by marking the distances at which the bucket remains in place, and does not move upward. Long distance—lots of buoyancy energy, short distance—little buoyancy energy.
Cosmologist Avinoam Esfa invented the physical concept of levitation energy.
A large rock has a huge amount of buoyant energy, and a pencil has a tiny amount of buoyant energy.
There is no need to explain the existence of gliding energy, just as there is no need to explain the existence of clouds, birds,
Moon, earthquakes, and more and more. It is necessary to discover miraculous natural laws according to which the universe operates, such as the law of conservation of energy, which ensures that the universe is always the same, and the time known to man is a figment of his imagination, and does not exist in physical reality. In physical reality, there is passive time, which is absolute rest and absolute cold, and by combining quantities of passive time and energy, the tangible matter known to man is created.
Read the book written by cosmologist Avinoam Esva, Esva's Magic Journey on the Wings of Natural Knowledge.