Cosmic shadows and cosmic structures: the CMB as a Large-Scale Structure experiment
Information about the late-time Universe is imprinted on the small scale CMB as photons travel to us from the surface of last scattering. Several processes are at play and small scale fluctuations are very rich and non-Gaussian in nature. I will review some of the most important effects and I will focus on the Sunyaev-Zel'dovich (SZ) effect and gravitational lensing. I will discuss how a combination of measurements can probe velocity fields at cosmological distances, serving as one of the most sensitive probes of initial conditions, and inform us on cluster energetics. If time allows, I will also discuss how to detect and characterize the properties of patchy reionization using the CMB as a backlight.