Silk, J.; Rubiño-Martin, J. A.; Rotti, A.; Remazeilles, M.; Ravenni, A.; Patil, S. P.; Mukherjee, S.; Maffei, B.; Mather, J.; Lesgourgues, J.; Kohri, K.; Kogut, A.; Hill, J. C.; Hernández-Monteagudo, C.; Hart, L.; Fixsen, D.; Finelli, F.; Dimastrogiovanni, E.; de Bernardis, P.; Delabrouille, J.; Burigana, C.; Basu, K.; Bolliet, B.; Ali-Haïmoud, Y.; Alvarez, M.; Abitbol, M. H.; Aghanim, N.; Chluba, J.; Sunyaev, R. A.; Switzer, E. R.
This Voyage 2050 paper highlights the unique science opportunities using spectral distortions of the cosmic microwave background (CMB). CMB spectral distortions probe many processes throughout the history of the Universe, delivering novel information that complements past, present and future efforts with CMB anisotropy and large-scale structure studies. Precision spectroscopy, possible with existing technology, would not only provide key tests for processes expected within the cosmological standard model but also open an enormous discovery space to new physics. This offers unique scientific opportunities for furthering our understanding of inflation, recombination, reionization and structure formation as well as dark matter and particle physics. A dedicated experimental approach could open this new window to the early Universe in the decades to come, allowing us to turn the long-standing upper distortion limits obtained with COBE/FIRAS some 25 years ago into clear detections of the expected standard distortion signals and also challenge our current understanding of the laws of nature.
Anisotropy of the Cosmic Microwave Background
The general goal of this project is to determine and characterize the spatial and spectral variations in the temperature and polarisation of the Cosmic Microwave Background in angular scales from several arcminutes to several degrees. The primordial matter density fluctuations which originated the structure in the matter distribution of the present