Speaker
Description
The traditional, real-space stacking estimator for the kinematic Sunyaev Zeldovich (kSZ) effect can be expressed as a simple angular power spectrum of two quantities: the CMB temperature field, and the galaxy momentum field. This power spectrum approach is mathematically equivalent to the stacking estimator, and comes with a number of advantages: it is fast to compute, easily connected to Fourier-space theory predictions, and its covariance is straightforward to compute -- without having to rely on simulations or empirical methods. Taking advantage of the already existing power spectrum infrastructure, it is also incredibly easy to seamlessly combine this kSZ measurement into any power spectra analyses: consistent scales cuts can be applied to the measurements, and the covariance of any pair of power spectra can be easily derived from the data.
Introducing the kSZ into analysis pipelines is especially useful to self-calibrate baryonic effects. The kSZ effect is sensitive to the baryonic physics on the line of sight -- namely, the electron density -- and therefore can provide a better handle on nuisance parameters introduced when modelling baryonic effects in LSS analyses. I will show results from a cosmic shear analysis on the DESI photometric Luminous Red Galaxies sample, which also includes the corresponding kSZ measurement.