Saturday 01 March 2025
A peculiar phenomenon has been observed in the behavior of ultralight dark matter, a mysterious substance thought to make up approximately 27% of our universe’s mass-energy budget. Researchers have discovered that when this dark matter is present in large quantities, it can form vortices – similar to those found in superfluids like liquid helium.
The finding, published in the journal Physical Review D, challenges our current understanding of how dark matter behaves on small scales. Dark matter’s properties are often described using a set of equations that mimic those used to model ordinary matter. However, these models fail to account for the peculiar behavior observed in this latest study.
To understand what’s happening, let’s delve into the world of ultralight dark matter. This type of dark matter is thought to have a mass as low as 10^-22 eV, making it an incredibly light particle. As a result, its de Broglie wavelength – the distance over which its wave-like properties become apparent – can be quite large, reaching up to kiloparsecs (thousands of light-years).
In this regime, dark matter’s behavior is governed by a nonlinear Schrödinger equation rather than the Vlasov equation typically used for ordinary particles. This nonlinearity leads to wave-like effects, such as interference patterns and the formation of solitons – stable, solitary waves that maintain their shape even as they propagate.
The researchers simulated the behavior of ultralight dark matter in two dimensions using a computer algorithm. They found that when the dark matter was initialized with random velocities and positions, it quickly settled into a state characterized by a rotating soliton at its center. This soliton was surrounded by a regular lattice of vortices, which gave rise to a solid-body rotation in the continuum limit.
The implications of this finding are significant. If ultralight dark matter is present in galaxies and galaxy clusters, it could be responsible for their observed rotation curves – the rate at which stars orbit around the center. This could provide a new explanation for the flat rotation curves often seen in these systems, which have been attributed to various forms of dark matter in the past.
Furthermore, the presence of vortices could affect the way ordinary matter behaves within galaxies. For instance, it may influence the formation of stars and planets or even play a role in the observed large-scale structure of the universe.
Cite this article: “Dark Matters Mysterious Dance: Vortices Formed from Ultralight Particles”, The Science Archive, 2025.
Ultralight Dark Matter, Vortices, Superfluids, Liquid Helium, Nonlinear Schrödinger Equation, Vlasov Equation, Solitons, Rotation Curves, Galaxies, Galaxy Clusters
Reference: Philippe Brax, Patrick Valageas, “Vortices and rotating solitons in ultralight dark matter” (2025).
