J/A+A/707/L4 z-independent theor. halo mass func. (Fernandez-Garcia+, 2026)
A redshift-independent theoretical halo mass function validated with the
UCHUU simulations.
Fernandez-Garcia E., Betancort-Rijo J.E., Prada F., Ishiyama T., Klypin A.,
Ruedas J.
<Astron. Astrophys. 707, L4 (2026)>
=2026A&A...707L...4F 2026A&A...707L...4F (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Redshifts
Keywords: cosmology: theory - dark matter - large-scale structure of Universe
Abstract:
We present a new theoretical framework for the halo mass function
(HMF) that accurately predicts the abundance of dark matter haloes
across an exceptionally wide range in mass and redshift. Building on a
generalised Press & Schechter model and triaxial collapse (GPS+), we
predict the HMF in terms of the variance of the linear density field,
with only a weak explicit dependence on halo mass and no explicit
dependence on redshift. The GPS+ model naturally provides the correct
normalization and high-mass behaviour without requiring empirical
fitting. We calibrate and validate the GPS+ model using the Uchuu
N-body simulation suite, which combines large cosmological volume and
high mass resolution under Planck cosmology. Using six simulations
with up to 300 realizations, we obtain precision HMF measurements
spanning halo masses in the range 6.5≤log(M200m/[h-1M☉])≤16
over 0≤z≤20, with reduced cosmic variance. Across this full domain,
the GPS+ model reproduces the simulated HMF with deviations typically
below 10-20%. Comparison with the Sheth-Tormen (ST) model shows
similar performance at z≲2, but markedly improved agreement at higher
redshifts, where ST can deviate by 70-80% while our model remains
within ∼20%. Finally, we assess the impact of the halo mass
definition: adopting the evolving virial overdensity of Bryan & Norman
(1998ApJ...495...80B 1998ApJ...495...80B) worsens agreement at low redshift and high
masses, whereas M200m yields a more universal, nearly
redshift-independent HMF.
Description:
The material included one table per redshift of the halo mass function
measured from the simulations used in the presented paper.
Each file contains the following columns: M200b, HMF, errHMF, counts,
sim, where M200b is the mass enclosed within overdensity 200ρb,
HMF is the HMF expressed as (M200b/rho_m)*(dn/dlnM)*(|dlnM/dlnsigma|),
errHMF is the error for the second column, counts is the number of
halos in the corresponding halo mass bin, and sim is a column that
tells the name of the simulation to which the HMF in that bin
corresponds to.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tableb1.dat 56 20 Availability of simulation snapshots at
each redshift for the different simulations
files/* . 20 Individual simulation results
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 F5.2 --- z Redshift
7 A1 ---- Phi-4096 [Y-] Snapshot exists for Phi-4096 simulation
9 A1 ---- Shin-Uchuu [Y-] Snapshot exists for Shin-Uchuu
simulation
11 A1 ---- Uchuu [Y-] Snapshot exists for Uchuu simulation
13 A1 ---- MU-140M [Y-] Snapshot exists for Mucho-Uchuu-140M
simulation
15 A1 ---- MU-1G [Y-] Snapshot exists for Mucho-Uchuu-1G
simulation
17 A1 ---- MU-6 [Y-] Snapshot exists for Mucho-Uchuu-6
simulation
19- 56 A38 ---- FileName Name of the file eith simulation results
in subdirectory files
--------------------------------------------------------------------------------
Byte-by-byte Description of file: files/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 E12.7 Msun M200m Mass enclosed within overdensity 200rhob,
in M☉/h unit
14- 25 E12.7 --- HFM Halo mass function expressed as
(M200m/rhom)*(dn/dlnM200b)*|dlnM200m/dlnsigma|
27- 38 E12.7 --- e_HFM Error on HMF
40- 51 E12.7 --- Nhalos Number of halos in the corresponding
halo mass bin
53- 72 A20 --- SimuName Name of the simulation to which the HMF
in that bin corresponds to
--------------------------------------------------------------------------------
Acknowledgements:
Elena Fernandez-Garcia, efdez(at)iaa.es
(End) Patricia Vannier [CDS] 11-Feb-2026