Universal at last? The splashback mass function of dark matter halos

Understand

The mass function of dark matter halos is one of the most fundamental statistics in structure formation.

• Many theoretical models (such as Press-Schechter theory) are based on the notion that it could be universal, meaning independent of redshift and cosmology, when expressed in the appropriate variables.
• However, simulations exhibit persistent non-universalities in the mass functions of the virial mass and other commonly used spherical overdensity definitions.
• We systematically study the universality of mass functions over a wide range of mass definitions, for the first time including the recently proposed splashback mass, Msp.