Particle identity of dark matter
About 85 percent of the matter in the universe neither emits nor absorbs light and is detected only through its gravity. Nobody knows what it is made of: a new elementary particle, a very light wave-like field, or black holes formed in the early universe.
Why it matters
Identifying dark matter would reveal physics beyond the Standard Model and fix the initial conditions for all cosmic structure.
Review
Bertone G., Hooper D., Silk J., Particle dark matter: evidence, candidates and constraints, Physics Reports, 2005. https://arxiv.org/abs/hep-ph/0404175 reference checked
Timestamp record
- Signed record
- f3bf70488fa9…
- Public log
- Entry 186, in checkpoint 2,123
- In the log by
- Block 969,698, 2026-10-03
This text was in the PubPhys log by that date. The date says nothing about when the problem was first posed.