Dark matter may exist in a hidden dimension, physicists propose
Physicists have substantiated the existence of dark matter through the fifth dimension (Photo: Unsplash)
Although dark matter makes up most of the universe's mass, humanity has still been unable to detect it. A new study suggests the reason may lie not in technical limitations, but in the very structure of space itself, according to research published in the scientific journal Physical Review D.
A team of astrophysicists led by Yu-Dai Tsai has put forward a hypothesis that dark matter and hypothetical particles — dark photons — are located in a hidden fifth spatial dimension.
This idea builds on the classical Kaluza–Klein concept from the 1920s, which holds that extra dimensions are curled up on a microscopic scale and therefore remain imperceptible.
However, unlike ordinary matter, which is confined to the four dimensions familiar to science (three spatial dimensions and time — ed.), dark particles have direct access to the fifth dimension.
Geometric resonance: the search for evidence
The key element of the new theory is the mechanism of dark matter resonance.
Instead of merely assuming a fixed mass ratio between the dark photon and the dark matter particle, the scientists derived it directly from the geometry of the extra dimension.
What does this mean?
Unlike previous models, which treated resonance as an unsubstantiated assumption, the Sheffield physicists substantiated it through the mathematical shape of 5D space. In the early universe, this resonance provided a strong interaction between ordinary and dark matter. As the cosmos expanded and cooled, this interaction weakened sharply — which explains why modern ground-based detectors have not registered direct signals.
Astrophysicists are attempting to test this theory experimentally. In particular, the search for dark photons is being carried out by the NA64 experiment at CERN, as well as by alternative projects such as HeRALD and Oscura.
Furthermore, the 5D resonance model explains why fewer dwarf galaxies are observed around the Milky Way and Andromeda than predicted by the standard cosmological model.
Although proponents of Modified Newtonian Dynamics (MOND) attempt to explain these anomalies by altering the laws of gravity without introducing new particles, the latest data from the Gaia space telescope and the Fermi satellite point in favor of models involving dark matter.
