Abstract

The kinetic Sunyaev-Zeldovich (kSZ) effect is the largest contribution to the cosmic microwave background (CMB) on small angular scales. Near-future CMB experiments (Simons Observatory, CMB -S4) will measure the kSZ effect with total signal-to-noise ~10^3. Despite the imminence of precise measurements, there are not many proposals for constraining cosmological parameters with the kSZ effect. This is because the kSZ effect is a complicated mix of cosmological information (large-scale velocities) and astrophysics (small-scale electron inhomogeneities).

I’ll present two proposals for disentangling kSZ cosmology from astrophysics. First, “kSZ velocity reconstruction”, which reconstructs large-scale 3-d cosmological modes, by combining kSZ measurements with an overlapping galaxy field. This is the best way to reconstruct cosmological modes on large scales (parametrically better than galaxy surveys or lensing) and will help constrain primordial non-Gaussianity. Second, I’ll describe a four-point statistic (the “power spectrum of the power spectrum”) which can constrain the epoch of inhomogeneous reionization, where there are few observational probes.