Dark matter is usually described as an invisible substance that responds only to gravity. But scientists are now exploring a more complex possibility: dark matter particles may also interact through a hidden force of their own.
A new study in the Journal of Cosmology and Astroparticle Physics (JCAP) examined what would happen if dark matter experienced an additional attractive force. The results were surprisingly counterintuitive. Although the force causes dark matter to gather more efficiently, it usually does not accelerate the growth of cosmic structure. Instead, it tends to slow that growth.
Why Scientists Are Considering a Dark Force
Interest in a possible "dark force" has increased as highly precise observations of the Universe have produced results that do not always align perfectly.
Measurements of cosmic expansion and the development of galaxies and other large structures sometimes appear to tell slightly different stories. Some observations of the distant Universe suggest that expansion may have proceeded somewhat more slowly in the past than the standard cosmological model predicts.
