Title: Astrophysicists Suggest Collisional Dark Matter Could Illuminate the Mysteries of the Universe
A recent research study conducted by a team of astrophysicists from the University of California Riverside has proposed a groundbreaking alternative theory that could explain mysteries surrounding the nature and behavior of dark matter. The prevailing idea regarding dark matter, known as the cold dark matter theory (CDM), posits that dark matter is made up of low-velocity particles that do not interact with each other. However, this theory has been a subject of debate, and the new findings suggest that some dark force causes dark matter particles to collide with each other, an idea known as Self-Interacting Dark Matter (SIDM).
Dark matter, which is responsible for about 85% of the mass of the universe, is described as “dark” due to its interactions with visible matter and electromagnetic radiation being weak or nonexistent. Furthermore, it is said to be “cold” as the sluggish particles are thought to move much more slowly than the speed of light. This theory explains the behavior of dark matter in cosmic structures such as galaxies. However, CDM struggles to explain extremely dense and extremely diffuse dark matter halos, which led the researchers to explore the collisional properties of SIDM as an alternative explanation.
The study found that SIDM could address the two extremes where cold dark matter doesn’t work well. In the case of ultradiffuse galaxies (UDGs), which are dwarf galaxies with extremely dim stars and spread-out star-forming gas, the researchers found that SIDM could explain why the dark matter halo reaches further out than in regular dwarf galaxies. Additionally, the formation of massive dark matter blobs that produce gravitational lensing was also supported by the collisional properties of SIDM.
The study results, recently published in The Astrophysical Journal Letters, shed light on the potential for self-interacting dark matter to explain the mysteries of dark matter behavior that have puzzled astrophysicists for decades. As we are yet to find a way to directly detect dark matter, these theoretical findings could pave the way for further research in the quest to unlock the secrets of dark matter. The researchers hope that someday, there could be a method of direct detection that will bring the mysteries of dark matter to light.
Source: Astrophysical Journal Letters 2023. DOI: 10.3847/2041-8213/ad0e09.