Me on top of the Moon Pyramid at Teotihuacán, México.

Hi! My name is Stijn Debackere.

I am a de Sitter fellow at Leiden Observatory, working with Joop Schaye and Henk Hoekstra.

I am a cosmologist, which means I try to study the Universe: what is it made up of and how does it evolve. It turns out that when we know the composition, it is “easy” to predict the evolution (easy means that General Relativity can tell us). I study how matter evolves through cosmic time using large agglomerations of galaxies, called galaxy groups and galaxy clusters. Their mass and how it is distributed, as well as how many of them we can find, contains a wealth of information about the cosmology of the Universe. For a layman’s introduction to my research, look here.