KIPAC Seminar: Probing Fundamental Physics in New Ways with the kSZ Effect

Speaker: Raagini Patki (Cornell) In Person and zoom

With the advent of high-resolution CMB data from current ground-based telescopes and upcoming Simons Observatory maps, the kinematic Sunyaev-Zel'dovich (kSZ) effect has become a powerful probe of baryons and velocity fields in the universe. By pairing CMB maps with large-scale structure (LSS) surveys such as DESI mapping millions of galaxies, upcoming kSZ measurements will potentially help shed light on enduring questions in cosmology and fundamental physics. In this talk, I will present two new statistical estimators employing the kSZ effect, which can help advance our understanding of these questions.

 I will first discuss a novel binned bispectrum of the form temperature-temperature-density, which extracts the kSZ signal using any projected-field tracing the LSS density. We show that this bispectrum has better scale-separation than the existing kSZ2 method, and peaks for certain squeezed triangles. We forecast high SNRs for SO cross-correlated with a linear galaxy field from WISE/VRO, and forecast competitive constraints on neutrino masses. In the second half of my talk, I will present a novel way to test gravity on the largest scales possible, by combining kSZ velocity-reconstruction with another CMB secondary - CMB lensing. We construct an estimator of the 'EG' statistic by taking a ratio of galaxy cross-correlations with lensing convergence and kSZ-reconstructed velocities. I will show forecasts for SO and ACT with DESI galaxy samples, and discuss the potential of this probe to distinguish between general relativity and modified gravity at linear scales.