Evolution of Massive Haloes in non-Gaussian Scenarios
M. Grossi, K. Dolag, E. Branchini, S. Matarrese, L. Moscardini
TL;DR
The paper investigates how primordial non-Gaussianity, parameterized by $f_{\rm NL}$, affects the formation and evolution of dark matter haloes in a $\Lambda$CDM universe using high-resolution N-body simulations. NG initial conditions are generated via the quadratic term $\Phi = \Phi_{\rm L} + f_{\rm NL}(\Phi_{\rm L}^2 - \langle \Phi_{\rm L}^2 \rangle)$ with $-1000 \le f_{\rm NL} \le 1000$, enabling exploration beyond current CMB constraints. The halo mass function is analyzed through $n(M,z,f_{\rm NL}) = n_G(M,z) F_{NG}(M,z,f_{\rm NL})$, and the high-mass tail is described by $R_{NG}(M,z,f_{\rm NL}) \simeq F_{NG}(M,z,f_{\rm NL})$ in the MVJ framework that uses $S_{3,M}$ and $\delta_*(z_c)$. The results show good agreement with MVJ predictions, highlighting that rare, massive haloes at high redshift can provide strong constraints on primordial NG and that positive $f_{\rm NL}$ yields earlier cluster formation while negative values delay it.
Abstract
We have performed high-resolution cosmological N-body simulations of a concordance LCDM model to study the evolution of virialized, dark matter haloes in the presence of primordial non-Gaussianity. Following a standard procedure, departures from Gaussianity are modeled through a quadratic Gaussian term in the primordial gravitational potential, characterized by a dimensionless non-linearity strength parameter f_NL. We find that the halo mass function and its redshift evolution closely follow the analytic predictions of Matarrese et al.(2000). The existence of precise analytic predictions makes the observation of rare, massive objects at large redshift an even more attractive test to detect primordial non-Gaussian features in the large scale structure of the universe.