Joint Modelling of Astrophysics Systematics for Cosmology with LSST

LSST will provide an unprecedented wealth of astronomical data, with which we will be able to tightly constrain the values of the parameters of our cosmological model, notably those which describe the poorly understood dark energy component. As weak lensing and galaxy clustering measurements provide a way to infer key cosmological quantities such as the dark matter distribution, the evolution of cosmic structure, and the expansion history of the Universe, detailed and rigorous analysis is necessary in order to glean as much information as possible from LSST measurements of these effects. This project will develop a consistent and reliable joint modelling framework for the intrinsic alignment of galaxies, galaxy bias and photometric redshift uncertainties: three key systematic effects impacting weak lensing and galaxy clustering. The outcome of this investigation will directly enable rigorous weak lensing and galaxy clustering constraints on cosmological parameters with LSST.