Primordial Nucleosynthesis Observations: Light Elements Measured

• Problem: pollution
  solution: trace evolution
  the circle, the circle of life
• Helium-4: extragalactic H II regions
  • dwarf (blue compact) galaxy I Zwicky 18: optical (HST); spectrum
• Deuterium: quasar absorption line systems
  • QSO absorption line systems: typical spectra
  • deuterium system HS 0105+1619 (O'Meara et al 2001):
    spectrum overview,
    hydrogen and deuterium lines
• and more: Pettini & Cooke
• Lithium-7: extreme Population II stars
  • extreme Pop II (halo) stars
    compare Li strength vs Ca (Smith+ 1998)
  • comparison: solar spectrum
  • example data: spectra (Ryan et al 1999); Bonifacio et al; Li vs Fe
  • another approachinterstellar Li in the SMC
• Helium-3: Galactic H II regions
  • a recent compilation: Bania et al 2002
  • also see Vangioni-Flam et al 2003

BBN: Theory vs Observations

• Predictions: Schramm plot (BDF 2011)
• Concordance? (BDF, Molaro, & Sarkar 2017)

BBN: Implications

• cosmic baryon abundance
• dark matter: two kinds!
  • baryonic dark matter (Fukugita, Peebles, & Hogan 1998): e.g., hot gas in collapsed structures and intergalactic gas (Nicastro+ 2018, Shull+ 2012); MACHOs (well, probably not MACHOs)
  • non-baryonic dark matter

BBN in Light of the CMB

• Overview: BBN+CMB Schramm plot
• Standard BBN: Light element CMB predictions vs observations (update to CFO 2008)

Particle Dark Matter

Prelude: Particle Physics Take II

• Conservation laws
• Fundamental particles
  • hadrons = composites of quarks
    (cf. drinking song from Finnegan's Wake )
    Particle Data Group : baryons and mesons
    mesons in space!
  • leptons: PDG listings
• Fundamental interactions
  force-carrying bosons: PDG listings
• Relativistic kinematics