Cosmology with imaging galaxy surveys: the impact of evolving galaxy bias and magnification

Understand

The joint analysis of galaxy clustering and galaxy-shear cross-correlations (galaxy-galaxy lensing) in imaging surveys constitutes one of the main avenues to obtain cosmological information.

• Analyses from Stage III surveys have assumed constant galaxy bias and weak lensing magnification coefficients within redshift bins.
• We use simple models of bias and magnification evolution to show that plausible levels of evolution impact cosmological parameter inference significantly for Stage IV surveys and possibly for current datasets as well.
• The distance weighting factors in galaxy-galaxy lensing cause it to have a different effective mean redshift within a lens bin than galaxy clustering.