Energy minima as a model for Dark Matter Haloes

by Marcello Musso (ICTP Kigali)

Monday 13 Sept 2021, 15:00 → 16:00 Europe/Berlin

SR2

Analytical models of structure formation are an important tool, complementary to N-body simulations, to investigate the formation of Dark Matter structures and the dependence of their statistics on cosmological parameters. They are also the only available way to investigate non-standard cosmological models for which simulations are not yet available. They rely on some non-linear map, typically inferred from spherical collapse, to relate topological features of the initial density field (number of maxima, minima, saddles, critical points...) to different types of structures and events (halos, voids, filaments, mergers...) in the cosmic web.
Conventional models are based on the heuristic assumption that virialized structures originate from initial regions that are maxima of the smoothed matter density field.
I will describe how shifting the focus from the initial density to the initial energy field, and characterizing protohalos from the minimization of the energy, provides: 1) a more physically sound model, 2) a better mathematical behavior, and 3) a better description of the location and shape of protohalo patches found in N-body simulations.