XIIIth School of Cosmology
November 12 - 18, 2017IESC, Cargèse
The CMB from A to Z
promises and challenges of the CMB as a cosmological probe

Cosmology Beyond Thermal Equilibrium: Future Steps with CMB Spectral Distortions

Jodrell Bank Center for Astrophysics at the University of Manchester


  1. Why are CMB spectral distortions so interesting?
  2. Theory of CMB spectral distortions and thermalization physics
  3. Distortions for different scenarios and what we may learn from them


Since the measurements with COBE/FIRAS in the mid-90's we know that the energy spectrum of the cosmic microwave background (CMB) is extremely close to that of a perfect blackbody. However, a number of early Universe processes should create spectral distortions at a level within reach of present day technology. In my lectures, I will give a broad-brush overview of recent theoretical and experimental developments, explaining why future measurements of the CMB spectrum will open an unexplored new window to early-universe and particle physics. This provides an exciting new path forward in CMB cosmology which is complementary to planned and ongoing searches for primordial B-mode polarization signals. I will also highlight some of the challenges due to foregrounds.


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