Viernes 28/11: Modelling Halo Statistics with the Evolution Mapping approach

Expositor:  Andrea Fiorilli (Max Planck Institute for Extraterrestrial Physics (MPE) – Garching bei München, Germany)

Fecha: viernes 28 de noviembre, 11:30 hs.

Resumen: Accurately modelling the abundance of dark matter haloes, described by the Halo Mass Function (HMF), is essential for understanding the large-scale structure of the Universe (LSS). The halo peak height primarily determines the HMF, but it is known to have additional dependencies on the cosmological parameters, as well as a weak scaling with redshift. These effects, of order 10%, are referred to as the non-universality of the HMF. Capturing the non-universality is crucial to fully exploit current and upcoming LSS surveys.

In this talk, I will present a new HMF model calibrated on a suite of high-resolution cosmological simulations. Our model is grounded in the Evolution Mapping framework, which helps identify the key parameters driving the non-universality. It achieves per cent-level accuracy across a broad range of halo masses and redshifts, for many halo mass definitions and over a wide range of cosmological parameters. We find that departures from universality are driven by the shape of the linear matter power spectrum at halo scales and, as predicted in the context of Evolution Mapping, the recent history of cosmic structure formation, whose memory is encoded in the abundance of haloes.