Relativistic Cosmology

The Structure of Cosmological Spacetime

• cosmological principle: maximal symmetry
• spaces of constant curvature
  coordinates: 2-sphere
• geometry of the universe
• Friedmann-Lemaitre-Robertson-Walker cosmic line element

Physics in a FLRW Universe

• redshifts
• time dilation observed in extragalactic Type Ia supernovae!
  
  • light curve width (1996, 2008)
  • evolution of spectral features (2005)
• distance measures
  • luminosity distance
  • angular diameter distance
    implications: CMB flucutations yield cosmic paramters
  • particle horizon
• causality in a FLRW universe