WarmAndFuzzy: the halo model beyond CDM

Abstract

Cold dark matter (CDM) is a well established paradigm to describe cosmological structure formation, and works extraordinarily well on large, linear, scales. Progressing further in dark matter physics requires being able to understand structure formation in the non-linear regime, both for CDM and its alternatives. This short note describes a calculation, and accompanying code, WarmAndFuzzy, incorporating the popular models of warm and fuzzy dark matter (WDM and FDM) into the standard halo model to compute the non-linear matter power spectrum. The FDM halo model power spectrum has not been computed before. The FDM implementation models ultralight axions and other scalar fields with $m_a\approx 10^{-22}\text{ eV}$. The WDM implementation models thermal WDM with mass $m_X\approx 1\text{ keV}$. The halo model shows that differences between WDM, FDM, and CDM survive at low redshifts in the quasi-linear and fully non-linear regimes. The code uses analytic transfer functions for the linear power spectrum, modified collapse barriers in the halo mass function, and a modified concentration-mass relationship for the halo density profiles. Modified halo density profiles (for example, cores) are not included, but are under development. Cores are expected to have very minor effects on the power spectrum on observable scales. Applications of this code to the Lyman-$\alpha$ forest flux power spectrum and the cosmic microwave background lensing power spectrum will be discussed in companion papers. \textsc{WarmAndFuzzy} is available online at \url{https://github.com/DoddyPhysics/HMcode}, where collaboration in development is welcomed.

8+2 pages, 2 figures, code available online at https://github.com/DoddyPhysics/HMcode

References in corpus (1)

• Astrophysics Source Code Library

Cited by in corpus (17)

• Ultra-Light Dark Matter
• CMB-S4 Science Case, Reference Design, and Project Plan
• Constraining the mass of light bosonic dark matter using SDSS Lyman-$\alpha$ forest
• Lyman-$\alpha$ forest and non-linear structure characterization in Fuzzy Dark Matter cosmologies
• Structure Formation and Microlensing with Axion Miniclusters
• On the road to percent accuracy: nonlinear reaction of the matter power spectrum to dark energy and modified gravity
• Unbiased constraints on ultralight axion mass from dwarf spheroidal galaxies
• Substructure of fuzzy dark matter haloes
• Future CMB tests of dark matter: ultra-light axions and massive neutrinos
• Ultra-light axions and the $S_8$ tension: joint constraints from the cosmic microwave background and galaxy clustering
• The Implications of a Pre-reionization 21 cm Absorption Signal for Fuzzy Dark Matter
• On the road to percent accuracy II: calibration of the non-linear matter power spectrum for arbitrary cosmologies
• Core-halo mass relation of ultralight axion dark matter from merger history
• Measuring the Small-Scale Matter Power Spectrum with High-Resolution CMB Lensing
• Spherical collapse in Generalized Dark Matter models
• Forecasts for Warm Dark Matter from Photometric Galaxy Surveys
• Weak Lensing Constraints on Dark Matter-Baryon Interactions with $N$-Body Simulations and Machine Learning