Cosmology

Contents

• Introduction
• Observations and Some Implications
  • Universe Contains Mass---Why has the Universe Not Collapsed?
  • Olbers' Paradox and the Dark Night Sky
  • Universe is Expanding
  • Universe is Uniform on Large Scales
    • Cosmological Principle
    • Perfect Cosmological Principle
  • No Center to the Expansion in 3-D Space
  • Review Questions
  • Cosmic Microwave Background Radiation
    • Observation
    • Interpretation
  • Matter to Energy to Matter Conversion
  • Cosmic Abundance of Helium and Hydrogen
    • ``Deuterium bottleneck''
    • Proportions
    • Elements heavier than Helium
    • Deuterium as a probe of the early universe
  • Evidence Supporting the General Big Bang Scheme
  • Review Questions
• Fate of the Universe
  • Depends on Mass (Curvature of Space)
  • Critical density
  • Is The Universe Open or Closed?
  • Dark Matter Observations:
    • Orbital speeds of stars in galaxies
    • Faint gas shells around ellipticals
    • Motion of galaxies in a cluster
    • Hot gas in clusters
    • Quasar spectra
    • Gravitational Lensing
  • Deriving the Geometry of the Universe from the Background Radiation
  • Review Questions
• Embellishments on the Big Bang
  • Flatness and Horizon problems
  • Inflation
  • The Cosmological Constant