AI Insight
Researchers have discovered that dark matter particles may exert an unexpected hidden force on each other that produces counterintuitive effects. While this force creates additional attraction that helps dark matter particles cluster together, it simultaneously makes dark matter behave as if it were lighter during the Universe's expansion. This reduction in effective mass weakens dark matter's gravitational influence, which typically slows down the formation and growth of cosmic structures rather than speeding it up as scientists initially expected.
Why it matters
This finding challenges existing models of how cosmic structures like galaxies and galaxy clusters form and evolve over time. Understanding this hidden force could help explain discrepancies between theoretical predictions and astronomical observations of large-scale structure in the Universe.
Understand the Science
Dark matter particles may exert a hidden force on one another, but its effects are stranger than expected. 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.
Source: Dark matter’s secret force does the opposite of what scientists expected