Non-universality of the mass function: dependence on the growth rate and power spectrum shape

Understand

The abundance of dark matter haloes is one of the key probes of the growth of structure and expansion history of the Universe.

• Theoretical predictions for this quantity usually assume that, when expressed in a certain form, it depends only on the mass variance of the linear density field.
• However, cosmological simulations have revealed that this assumption breaks, leading to 10-20% systematic effects.
• In this paper we employ a specially-designed suite of simulations to further investigate this problem.