| Name: | Shabbir Shaikh |
| Affiliation: | Arizona State University, Tempe, Arizona, USA |
| Conference ID : | ASI2023_500 |
| Title : | CMB weak lensing and galaxy weak lensing cross-correlation using ACT-DR4 and DES-Y3 |
| Authors : | Shabbir Shaikh, Ian Harrison, Alexander van Engelen and contributors from the Atacama Cosmology Telescope collaboration, Dark Energy Survey collaboration |
| Mode of Presentation: | Oral |
| Abstract Category : | General Relativity and Cosmology |
| Abstract : | Weak gravitational lensing of the Cosmic Microwave Background (CMB) and galaxies is a clean probe of the total matter in the universe as it probes the baryonic and dark matter. The matter that gravitationally lenses galaxies, which are at lower redshifts than the CMB, also contributes to the lensing of the CMB, but with different weighing. Resultant cross-correlation between the CMB weak lensing and weak lensing of galaxies offers a way to put robust constraints on the cosmological and astrophysical parameters. We measure the angular power spectrum between the weak lensing convergence map provided by the Atacama Cosmology Telescope (Data Release-4 data) and the weak lensing shear map provided by Dark Energy Survey (Year-3 data). This cross-correlation is immune to certain systematics affecting either survey. We use the power spectrum measurement, which passes specific null tests, to constrain the density of the matter and the amplitude of the fluctuations in the matter distribution. We also explore constraints on the amplitude of intrinsic galaxy alignment, with CMB as a high redshift source plane complementary to the lensing source galaxies. |
