Introduction to Dark Matter Theory

• New research proposes universe filled with singularities as dark matter explanation
• Paper focuses on "naked singularities" - singularities without event horizons
• Unlike black holes which have horizons (boundaries preventing light escape), naked singularities have no horizon hiding the singularity

Black Holes vs Naked Singularities

• Both are solutions to Einstein's general relativity theory
• Black holes: confirmed to exist, have event horizons concealing singularities
• Naked singularities: existence unknown, singularity visible without horizon
• Cosmic censorship hypothesis: suggests all singularities should be hidden behind horizons
  • Never fully mathematically proved
  • Controversial whether correct in nature
  • Computer simulations suggest naked singularities can form from gravitational collapse

Physics of Singularities

• Most physicists don't believe singularities are real
• When singularities appear in theory mathematics, indicates theory breakdown
• High density/curvature regions require quantum gravity theory (which doesn't exist yet)
• Naked singularities provide "plain view" access to quantum gravitational effects regions
• Previous research 10 years ago explored gravitational lensing from naked singularities
  • Abandoned because difficult to distinguish from black holes

Early Universe Formation Theory

• Early universe: hot plasma with density fluctuations (not entirely smooth)
• Higher density regions contract under gravity
• Normally form stars and galaxies
• Large enough fluctuations can form primordial black holes
• New paper proposes: could also form primordial naked singularities

Primordial Black Holes as Dark Matter

• Observable black holes: formed from stellar collapse or matter accumulation, extremely massive
• Primordial black holes: could be created at any mass, fairly small, distributed throughout universe
• Previously considered dark matter candidates
• Idea mostly discarded due to observational conflicts:
  • Dark matter must be ~4x normal matter mass (universe average)
  • Within galaxies like Milky Way: need 10-20x more dark matter than normal matter
  • Expected observable consequences not seen:
    • Gravitational lensing
    • Cosmic microwave background distortions
    • Star collapse from black hole passage
    • Light flashes from small black hole evaporation

Naked Singularities Dark Matter Proposal

• Early universe created primordial naked singularities instead of primordial black holes
• Similar gravitational lensing effects to black holes
• Might not collapse stars as much
• Could be more viable dark matter candidates
• First paper on this specific idea
• Authors expected to follow up with detailed analysis

Assessment and Challenges

• Mathematics likely workable to match observations
• Main problem: formation conditions for naked singularities vs black holes are similar
• Difficult to explain early universe plasma conditions creating many naked singularities without also creating many black holes
• Since primordial black holes largely ruled out, would likely rule out naked singularities too
• Author plans to monitor idea development