Special Seminar

Speaker: 【Cancelled】Mathew Madhavacheril (Perimeter Institute)
Title: Cosmological applications of the kSZ effect
Date: Wed, Apr 22, 2020, 15:30 - 16:30
Place: Seminar Room A
Abstract: We show how kSZ tomography measures a bispectrum containing a cosmological power spectrum of the velocity field and an astrophysical power spectrum of the electron density. While these are degenerate up to an overall amplitude (the "galaxy optical depth"), scale-dependent effects on large scales are much better constrained by the inclusion of kSZ on top of galaxy clustering while assuming nothing about the optical depth of galaxy clusters. This allows for factors of >2x improvement on the amplitude of local primordial non-gaussianity fNL with the absolute constraint from Simons Observatory + LSST crossing the theoretically interesting threshold of sigma(fNL)<1. Next, we discuss ways of measuring the amplitude of the growth rate by breaking the optical depth degeneracy using the dispersion measures of fast radio bursts (FRBs).
Finally, we discuss calibration of baryonic feedback in weak lensing measurements using kSZ measurements of the electron density profile.