The Cosmic Microwave Background (CMB) encodes a wealth of signals which inform cosmology and fundamental physics. Improved measurements will constrain primordial gravitational waves providing new insights into the ultra high energy physics of the early universe; give new constraints on the dark universe providing evidence for, or ruling out light relativistic degrees of freedom including...
Astrophysical gamma rays from 511 keV up to greater than 1 PeV have been detected from multiple sources and serve as unique probes of high energy physics. The existence of the highest energy gamma rays constrains Lorentz invariance violation beyond the Plank mass scale. Signatures of various forms of dark matter can also be discovered with gamma ray observations. Gamma rays from distant...