Halo abundances in the f_{nl} model

TL;DR

This paper extends the excursion set moving barrier model to include local non-Gaussian f_{nl} effects, providing a framework to better understand halo abundances under non-Gaussian initial conditions.

Contribution

It generalizes the moving barrier model for halo abundances to incorporate local non-Gaussian f_{nl} effects, clarifying assumptions and potential improvements.

Findings

Consistent with previous constant barrier results

Highlights implicit assumptions in the model

Suggests ways to improve analytic solutions

Abstract

We show how the excursion set moving barrier model for halo abundances may be generalized to the local non-Gaussian f_{nl} model. Our estimate assumes that the distribution of step sizes depends on f_{nl}, but that they are otherwise uncorrelated. Our analysis is consistent with previous results for the case of a constant barrier, and highlights some implicit assumptions. It also clarifies the basis of an approximate analytic solution to the moving barrier problem in the Gaussian case, and shows how it might be improved.