PIRSA:15070088

Video URL

https://pirsa.org/15070088

Cosmological tests of gravity: Unpacking degeneracies - Danielle Leonard

(2015). Cosmological tests of gravity: Unpacking degeneracies - Danielle Leonard. Perimeter Institute for Theoretical Physics. https://pirsa.org/15070088

Cosmological tests of gravity: Unpacking degeneracies - Danielle Leonard. Perimeter Institute for Theoretical Physics, Jul. 21, 2015, https://pirsa.org/15070088 

          @misc{ scivideos_PIRSA:15070088,
            doi = {10.48660/15070088},
            url = {https://pirsa.org/15070088},
            author = {},
            keywords = {Cosmology},
            language = {en},
            title = {Cosmological tests of gravity: Unpacking degeneracies - Danielle Leonard},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2015},
            month = {jul},
            note = {PIRSA:15070088 see, \url{https://scivideos.org/index.php/pirsa/15070088}}
          }
Talk numberPIRSA:15070088
DOI10.48660/15070088
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

Current and near-future cosmological surveys can provide powerful tests of gravity on the largest scales. However, in order to extract this information, it is essential to understand the host of parameter degeneracies which may arise. I present two approaches towards this goal, with a focus on the use of weak gravitational lensing measurements in combination with other probes. First, I discuss a novel expression for a weak lensing power spectrum under alternative theories of gravity. Obtained by considering small deviations from GR, this expression separates various physical effects of modifications to GR, thus allowing a quantitative understanding of degeneracies between gravitational parameters. Second, I present an investigation into the theoretical uncertainty inherent to the popular gravity-testing statistic E_G. By improving our understanding of the theoretical value of E_G, we can use it to make more robust statements about the viability of alternative theories of gravity on cosmological scales.