Astronomy Colloquium (10.13/2021): Tightening geometric and dynamical constraints on dark energy and gravity: galaxy clustering, intrinsic alignment and kinetic Sunyaev-Zel’dovich effect
Title: Tightening geometric and dynamical constraints on dark energy and gravity: galaxy clustering, intrinsic alignment and kinetic Sunyaev-Zel’dovich effect
Speaker: Teppei Okumura
Abstract: Conventionally, in galaxy surveys, cosmological constraints on the growth and expansion history of the universe have been obtained from the measurements of redshift-space distortions and baryon acoustic oscillations embedded in the large-scale galaxy density field. In this talk, we present how well one can improve the cosmological constraints from the combination of the galaxy density field with velocity and tidal fields, which are observed via the kinetic Sunyaev-Zel’dovich (kSZ) and galaxy intrinsic alignment (IA) effects, respectively. For illustration, we consider the deep galaxy survey by Subaru Prime Focus Spectrograph, whose survey footprint perfectly overlaps with the imaging survey of the Hyper Suprime-Cam and the CMB-S4 experiment. We find that adding the kSZ and IA effects significantly improves cosmological constraints, particularly when we adopt the non-flat cold dark matter model which allows both time variation of the dark energy equation-of-state and deviation of the gravity law from general relativity. As another example, we also consider the wide galaxy survey by the Euclid satellite, in which shapes of galaxies are noisier but the survey volume is much larger. We demonstrate that under the model mentioned above, the clustering analysis combined with kSZ and IA from the deep survey can achieve tighter cosmological constraints than the clustering-only analysis from the wide survey.