What is the Halo Mass Function in a Fuzzy Dark Matter Cosmology?

TL;DR

This paper calculates the halo mass function in fuzzy dark matter cosmology, compares it with simulations, and constrains the particle mass using high-redshift galaxy observations.

Contribution

It introduces a method to compute the FDM halo mass function with a sharp-k window and constrains the FDM particle mass based on observational data.

Findings

Peak halo mass at ~10^10 solar masses for 2×10^−22 eV FDM.

FDM particle mass constrained to be ≥ 2×10^−22 eV.

Comparison shows agreement between analytical and simulation results.

Abstract

Fuzzy dark matter (FDM) or wave dark matter is an alternative theory designed to solve the small-scale problems faced by the standard cold dark matter proposal for the primary material component of the universe. It is made up of ultra-light axions having mass $\sim 10^{-22}$ eV that typically have de Broglie wavelength of several kpc, alleviating some of the apparent small-scale discrepancies faced by the standard $\Lambda$CDM paradigm. In this paper, we calculate the halo mass function for the fuzzy dark matter using a sharp-k window function and compare it with one calculated using numerical simulations, finding the peak mass at roughly $10^{10} {M_{\odot}}$ for a particle mass of $2\times 10^{-22}$ eV. We also constrain the mass of FDM particle to be $\gtrapprox 2\times10^{-22}$ eV using the observations of high-redshift ($z\sim 10$) lensed galaxies from CLASH survey.