HMF: Halo Mass Function Model (Fernandez-Garcia 2025)

This repository contains the implementation of the Halo Mass Function (HMF) model based on the Fernandez-Garcia et al. (2025) formalism. The code is designed to work with the Colossus cosmology toolkit and provides a robust way to calculate halo abundances across different mass ranges and cosmologies.

Installation

Prerequisites

You will need Python 3.7+ and the following dependencies:

• numpy
• scipy
• colossus

Install Dependencies

pip install numpy scipy colossus

Usage

You can use the HaloMassFunction class to calculate the mass function at a specific redshift.

import numpy as np
from HMF import HaloMassFunction

# Initialize the model at z=0 with a specific mass definition
hmf_model = HaloMassFunction(z=0.0, mdef='m200b')

# Define a range of masses (M_sun/h)
masses = np.logspace(10, 15, 100)

# Calculate dn/dlnM
abundance = hmf_model.n0(masses)

# abundance is now an array containing the halo density

Model Details

The model implements the following components:

• b(M) and c(M): Mass-dependent fitting functions for the peak height logic.
• F(M): The cumulative collapse fraction.
• n0(M): The differential mass function $dn/d\ln M$.

References

If you use this code in your research, please cite: Fernandez-Garcia+25.

License

This project is licensed under the MIT License.