Institute for Advanced Study Informal Astrophysics Seminar

Weak lensing of high redshift galaxies and quasars leads to a well known adjustment of galaxy/quasar source counts called magnification bias. I will discuss how magnification bias complicates high redshift measurements of the integrated Sachs Wolfe effect, distorts the observed angular and 3D galaxy correlation functions, and alters measurements of the Lyman-alpha forest. Magnification bias can have a surprisingly large effect on these observables and potentially bias the inferred value of cosmological parameters.