Improved Halo Model Calibrations for Mixed Dark Matter Models of Ultralight Axions
We study the implications of relaxing the requirement for ultralight axions to account for all dark matter in the Universe by examining mixed dark matter (MDM) cosmologies with axion fractions $f \leq 0.3$ within the fuzzy dark matter (FDM) window $10^{-25}$ eV $\lesssim m \lesssim 10^{-23}$ eV. Our...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal Article |
| Language: | English |
| Published: |
17-09-2024
|
| Subjects: | |
| Online Access: | Get full text |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | We study the implications of relaxing the requirement for ultralight axions
to account for all dark matter in the Universe by examining mixed dark matter
(MDM) cosmologies with axion fractions $f \leq 0.3$ within the fuzzy dark
matter (FDM) window $10^{-25}$ eV $\lesssim m \lesssim 10^{-23}$ eV. Our
simulations, using a new MDM gravity solver implemented in AxiREPO, capture
wave dynamics across various scales with high accuracy down to redshifts
$z\approx 1$. We identify halos with Rockstar using the CDM component and find
good agreement of inferred halo mass functions (HMFs) and concentration-mass
relations with theoretical models across redshifts $z=1-10$. This justifies our
halo finder approach a posteriori as well as the assumptions underlying the MDM
halo model AxionHMcode. Using the inferred axion halo mass - cold halo mass
relation $M_{\text{a}}(M_{\text{c}})$ and calibrating a generalised smoothing
parameter $\alpha$ to our MDM simulations, we present a new version of
AxionHMcode. The code exhibits excellent agreement with simulations on scales
$k< 20 \ h$ cMpc$^{-1}$ at redshifts $z=1-3.5$ for $f\leq 0.1$ around the
fiducial axion mass $m = 10^{-24.5}$ eV $ = 3.16\times 10^{-25}$ eV, with
maximum deviations remaining below 10%. For axion fractions $f\leq 0.3$, the
model maintains accuracy with deviations under 20% at redshifts $z\approx 1$
and scales $k< 10 \ h$ cMpc$^{-1}$, though deviations can reach up to 30% for
higher redshifts when $f=0.3$. Reducing the run-time for a single evaluation of
AxionHMcode to below $1$ minute, these results highlight the potential of
AxionHMcode to provide a robust framework for parameter sampling across MDM
cosmologies in Bayesian constraint and forecast analyses. |
|---|---|
| DOI: | 10.48550/arxiv.2409.11469 |