Dark Energy from gravitational lensing

One of the biggest unsolved questions in cosmology is what Dark Energy is, making up 70% of the Universe and causing its expansion to accelerate. At Oxford we are involved in a variety of observational projects aimed at measuring the behaviour of Dark Energy, happening both this decade and next. Gravitational lensing probes the growth of structure and expansion of the Universe by measuring the bending of light by cosmic structures. It can be seen in the optical and infrared using the shear of galaxies, and also by the distortion of the Cosmic Microwave Background. This project will focus on how to best combine and correlate these two types of lensing measurements, to reduce the effect of systematic errors, and then to better understand the dark sector.

This project will involve both theoretical work and statistical data analysis, and will focus both on undertaking and interpreting cross-correlations with current data (including from ACTPol and KiDS, with overlapping areas of a few hundred square degrees), and preparations for the upcoming Large Synoptic Survey Telescope, Euclid satellite and Advanced ACTPol experiment, which will have overlapping measurements over half the sky.