Speaker
Description
I examine galaxy peculiar velocities as a cosmological probe and compute their kernels in standard perturbation theory up to second order. With these, I construct the peculiar velocity power spectrum and bispectrum at tree level. I find agreement with the literature for the former and I derive the expression for the latter for the first time. As a byproduct, I also derive the bispectrum of the so-called momentum density, i.e. the density-weighted peculiar velocity field. Focussing on the two new bispectra, I compare them to the well-studied bispectrum of galaxy clustering. I find that, in general, both of them can provide constraints on the growth rate of cosmic structures tighter than those obtained with the galaxy clustering bispectrum, making them a compelling cosmological probe in themselves and, all the more so, to complement standard galaxy clustering analyses.
