Dark Energy from gravitational lensing

Lead Research Organisation: University of Oxford
Department Name: Oxford Physics

Abstract

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.

Publications

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Harnois-D (2017) KiDS-450: tomographic cross-correlation of galaxy shear with Planck lensing in Monthly Notices of the Royal Astronomical Society

Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/N504233/1 01/10/2015 31/03/2021
1659475 Studentship ST/N504233/1 01/10/2015 31/03/2019 Naomi Clare Robertson
 
Description Atacama Cosmology Telescope 
Organisation Atacama Cosmology Telescope
Country Chile 
Sector Charity/Non Profit 
PI Contribution I am a 'remote observer', which involves running the telescope on a 24 hour shift twice a month for the collaboration.
Collaborator Contribution Expertise from members and access to data.
Impact In progress.
Start Year 2015
 
Description Kilo Degree Survey 
Organisation Leiden University
Department Kilo-Degree Survey
Country Netherlands 
Sector Public 
PI Contribution Lead of SZ-selected cluster mass calibration project. Lead of ACTxKiDS cross-correlation project. Lead of filament lensing project.
Collaborator Contribution Expertise from team members and data access.
Impact None
Start Year 2015