The Cosmic Microwave Background

The Isotropic CMB Observed

• Discovery
  • Penzias & Wilson's prizewinning paper (1965)
  • Princeton group's companion paper
  • precursors & missed opportunities
    theory: Alpher & Herman prediction and update with unfortunate footnote on p. 206
    observation: McKellar cyanogen rotational temperature paper, punchline, and followup
• Present data
  • peeling away foregrounds from signal
  • frequency spectrum, in context of cosmic photon backgrounds (Hill+ 2018)
  • temperature
  • polarization

Decoding the CMB Epoch: a Scattering Problem

• the present transparency of the U to the CMB
• the CMB as a scattering problem
• lightning review of scattering
  • cross sections
  • scattering rates
• photon scattering by cosmic matter
• surface of last scattering