The Projected Bispectrum of Large-scale Structure in the Universe

Alex Miranthis will undertake a project in theoretical cosmology on the science exploitation of higher-order correlation functions (notably the bispectrum or three-point correlator) extracted from galaxy surveys, with the objective of constraining cosmological models of the early Universe. The focus of the project will be determining the projected bispectrum from publicly-available galaxy surveys, including the most recent data releases from the Sloan Digital Sky Survey and the Dark Energy Survey, using galaxy data in several tomographic redshift bins. The methodology will be based around the well-tested Planck satellite bispectrum estimator MODAL, developed by Fergusson and Shellard, and relevant survey expertise will be available from two core DES members (MacCrann and Friedrich). This work will also study cross-correlations with CMB data, including new data from the Simons Observatory. The outcomes include breaking degeneracies on cosmological parameters (notably galaxy bias parameters) and providing new constraints on primordial non-Gaussianity from inflation.