Sheean Jolicoeur


Email: jolicoeursheean at

Sheean Jolicoeur

The next generation of large scale galaxy surveys e.g. the SKA will increasing rely on the galaxy 3-point correlation function or equivalently its Fourier transform which is the galaxy bispectrum to put strong constraints on cosmological parameters. Our key goal is to eliminate a large number of inflationary models and one way of doing it is by measuring the amount of non-Gaussianity given by the fNL parameter. This can be done using the galaxy bispectrum but the task is long and complicated. The effect of fNL in the standard Newtonian bispectrum becomes important on significantly large scales where also non-linear relativistic (GR) lightcone projection effects dominate. These GR effects can highly contaminate the signal of fNL and may lead to false interpretation of non-Gaussianity. Therefore, there is a need to understand how non-linear GR corrections behave in the bispectrum such that they can be subtracted off from observations in order to extract the pure fNL contribution. 

My work aims at testing GR on large scales of the Universe. It is purely theoretical/computational and looks at these non-linear GR projection effects on large scales through the galaxy bispectrum. I also work on Fisher Forecasts for galaxy surveys such as Euclid and SKA, using the galaxy bispectrum.