Less dark matter required than previously anticipated
A new study suggests that the universe may require less dark matter than previously thought, potentially challenging existing models and reshaping our understanding of cosmic structure formation.
Background
- **Dark matter** is the invisible, non-luminous mass that physicists believe makes up about 85% of the universe's matter, inferred from its gravitational effects on visible galaxies and stars — but it has never been directly detected.
- This new paper in *Physical Review D* argues that the standard model of cosmology may have overestimated the amount of dark matter needed. By revising assumptions about how galaxies form and evolve, the authors show that some gravitational anomalies attributed to dark matter could instead be explained by ordinary (baryonic) matter and feedback processes like supernova explosions.
- If correct, this would significantly reduce the "missing mass" problem, though it does not eliminate the need for dark matter entirely. The finding is controversial because it challenges the widely accepted ΛCDM (Lambda Cold Dark Matter) cosmological model.
- The journal *Physical Review D* is a leading peer-reviewed publication for particle physics, field theory, gravitation, and cosmology, published by the American Physical Society.