Jolicoeur, SheeanMaartens, RoyDlamini, Simthembile2023-05-092023-05-092023Jolicoeur, S. et al. (2023). Constraining primordial non-gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys. European Physical Journal C, 83(4), 320. 10.1140/epjc/s10052-023-11482-21434-605210.1140/epjc/s10052-023-11482-2http://hdl.handle.net/10566/8904Surveys of the matter distribution contain ‘fossil’ information on possible non-Gaussianity that is generated in the primordialUniverse. This primordial signal survives only on the largest scales where cosmic variance is strongest. By combining different surveys in a multi-tracer approach, we can suppress the cosmic variance and significantly improve the precision on the level of primordial non-Gaussianity.We consider a combination of an optical galaxy survey, like the recently initiated DESI survey, together with a new and very different type of survey, a 21cm intensity mapping survey, like the upcoming SKAO survey.enAstrophysicsAstronomyCosmologyPhysicsGalaxy evolutionArticle