An illustration of dark matter at the heart of the Milky Way resonating through a higher dimension
(Image credit: Robert Lea (created with Canva))
Two major mysteries in science, the nature of dark matter and the possible existence of higher dimensions, could be linked, new research suggests. The team behind a new study proposes that dark matter may be so strange and ghost-like because it is in tune with a fifth dimension.When scientists discuss "extra dimensions," they aren't talking about other universes in which another evil version of you exists (and with a beard). Instead, they refer to dimensions that could be "curled up" with reality alongside the standard four-dimensional spacetime, consisting of the three dimensions of space and one dimension of time.While these extra dimensions remain highly speculative, they have become a hot topic, especially as string theory, the most popular extension to standard physics, relies upon the existence of at least 11 dimensions. Scientists are more sure that dark matter exists, but proving its existence still remains troubling because, despite its gravity literally holding galaxies together and outweighing ordinary matter by around five to one, it remains effectively invisible because it doesn't interact with light and it simply ghosts through ordinary matter."Understanding dark matter would represent a profound advance in humanity's knowledge of the cosmos and what it is made of," team member Yu-Dai Tsai of the University of Sheffield said in a statement."Our research gives physicists clear new targets in the search for dark matter, while connecting two of the biggest ideas in fundamental physics: the mystery of dark matter and the existence of hidden dimensions."Dark photons play dark matter like a violinThough the main idea is that dark matter may operate in the fifth dimension, this new research expands upon that concept with another theory. It suggests that dark matter exists with another inhabitant of the fifth dimension, a force-carrying particle called a "dark photon."Standard photons are the constituent particles of electromagnetic radiation, or light; dark photons would be similar but for a hypothetical "dark force." The team's new proposal would see the unique geometry of the fifth dimension causing the masses of dark matter particles to form an arrangement that gives rise to a "dark matter resonance." This is akin to the intense vibration of a musical instrument at certain notes."Dark matter resonance is already known to be a powerful idea, with the potential to change our understanding of how dark matter was produced in the early universe and how we search for it today," team member Yu-Dai Tsai of the University of Sheffield said in a statement. "But many previous resonant dark matter models have treated the resonance as an assumption. This work gives a possible deeper origin for it: the resonance may come directly from the geometry of hidden dimensions."
