Dark matter’s secret force does the opposite of what scientists expected

Dark matter particles may exert a hidden force on one another, but its effects are stranger than expected.

The short version

• An extra attraction helps the particles cluster, yet it also makes dark matter effectively lighter as the Universe expands.
• That weakens its gravitational impact and usually slows the growth of cosmic structure rather than accelerating it.
• Dark matter is usually described as an invisible substance that responds only to gravity.

What happened

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.

Why it matters

The results were surprisingly counterintuitive.

Summary by Nerd News Network. Read the full article at ScienceDaily — Top Science via the links above and below.