The halo mass function and filaments in full cosmological simulations with fuzzy dark matter

Abstract

Fuzzy dark matter (FDM) is a dark matter candidate consisting of ultra-light scalar particles with masses around $10^{-22}\mathrm{eV}/c^2$, a regime where cold bosonic matter behaves as a collective wave rather than individual particles. It has increasingly attracted attention due to its rich phenomenology on astrophysical scales, with implications for the small-scale tensions present within the standard cosmological model, $\Lambda$CDM. Although constraints on FDM are accumulating in many different contexts, very few have been verified by self-consistent numerical simulations. We present new large numerical simulations of cosmic structure formation with FDM, solving the full Schrödinger-Poisson (SP) equations using the AxiREPO code, which implements a pseudo-spectral numerical method. Combined with our previous simulations, they allow us to draw a four-way comparison of matter clustering, contrasting results (such as power spectra) for each combination of initial conditions (FDM vs. CDM) and dynamics (SP vs. $N$-body). By disentangling the impact of initial conditions and non-linear dynamics, we can gauge the validity of approximate methods used in previous works, such as ordinary $N$-body simulations with an FDM initial power spectrum. Due to the comparatively large volume achieved in our FDM simulations, we are able to measure the FDM halo mass function from full wave simulations for the first time, and compare to previous results obtained using analytic or approximate approaches. We find that, due to the cut-off of small-scale power in the FDM power spectrum, haloes are linked via continuous, smooth, and dense filaments throughout the entire simulation volume (unlike for the standard $\Lambda$CDM power spectrum), posing significant challenges for reliably identifying haloes. We also investigate the density profiles of these filaments and compare to their CDM counterparts.

18 pages, 13 figures; submitted to MNRAS

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Cited by in corpus (20)

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• Confronting fuzzy dark matter with the rotation curves of nearby dwarf irregular galaxies
• ALP Dark Matter Mini-Clusters from Kinetic Fragmentation
• Structure, Kinematics, and Observability of the Large Magellanic Cloud's Dynamical Friction Wake in Cold vs. Fuzzy Dark Matter
• Warm and Fuzzy Dark Matter: Free Streaming of Wave Dark Matter
• COZMIC. I. Cosmological Zoom-in Simulations with Initial Conditions Beyond Cold Dark Matter
• Nested solitons in two-field fuzzy dark matter
• Early Growth of Structure in Warm Wave Dark Matter
• Post-inflationary structure formation boosted by parametric self-resonance
• Fuzzy dark matter simulations
• Improved Halo Model Calibrations for Mixed Dark Matter Models of Ultralight Axions
• Galaxy formation with wave/fuzzy dark matter: The core-halo structure and the solitonic imprint
• Interference in Fuzzy Dark Matter Filaments: Idealised Models and Statistics
• The SRG/eROSITA all-sky survey: Constraints on Ultra-light Axion Dark Matter through Galaxy Cluster Number Counts
• Comparison of two different integration methods for the (1+1)-Dimensional Schrödinger-Poisson Equation
• Ultra-light dark matter with non-canonical kinetics reopening the mass window
• Emulating the Non-Linear Matter Power-Spectrum in Mixed Axion Dark Matter Models
• Nearest neighbour analysis as a new probe for fuzzy dark matter
• Fuzzy dark matter dynamical friction: stalling of globular clusters induced by dynamical heatings