Cosmic magnification: nulling the intrinsic clustering signal
  We investigate the extent to which the pure magnification effect of
gravitational lensing can be extracted from galaxy clustering statistics, by a
nulling method which aims to eliminate terms arising from the intrinsic
clustering of galaxies. The aim is to leave statistics which are free from the
uncertainties of galaxy bias. We find that nulling can be done effectively,
leaving data which are relatively insensitive to uncertainties in galaxy bias
and its evolution, leading to cosmological parameter estimation which is
effectively unbiased. This advantage comes at the expense of increased
statistical errors, which are in some cases large, but it offers a robust
alternative analysis method to cosmic shear for cosmological imaging surveys
designed for weak lensing studies, or to full modelling of the clustering
signal including magnification effects.
