Testing dark matter halo properties using self-similarity

Understand

We use self-similarity in N-body simulations of scale-free models to test for resolution dependence in the mass function and two-point correlation functions of dark matter halos.

• We use 1024$^3$ particle simulations performed with ABACUS, and compare results obtained with two halo finders: friends-of-friends (FOF) and ROCKSTAR.
• The FOF mass functions show a systematic deviation from self-similarity which is explained by resolution dependence of the FOF mass assignment previously reported in the literature.
• Weak evidence for convergence is observed only starting from halos of several thousand particles, and mass functions are overestimated by at least as much as 20-25 percent for halos of 50 particles.