Arrangör/Organiser: OKC Colloquium Committee
Kontakt/Contact: Evan O'Connor
Ingen föranmälan krävs/No registration required

The highest peaks in the cosmic density field host large clusters of galaxies that are observable over vast distances. Their abundance is a sensitive probe of the physics of structure formation, and in my talk I will explain how clusters can be used to study effects of neutrinos or look for signatures of modified gravity.
But on a more general level, these massive overdensities form a striking part of the complicated shape of the large-scale structure. Gravitational collapse turns the simple initial conditions into the complicated cosmic web we observe today, consisting of matter filaments that surround large void regions. Galaxy clusters form in the knots of this cosmic web, and in the second part of the talk I will outline how to connect their abundance to the full shape of the underlying dark matter field, which is not captured by the power spectrum or related two-point statistics that are commonly used in cosmology.