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Title: An attractive model: simulating fuzzy dark matter with attractive self-interactions
ABSTRACT Fuzzy dark matter (FDM), comprised of ultralight ($$m \sim 10^{-22}\,{\rm eV}$$) boson particles, has received significant attention as a viable alternative to cold dark matter (CDM), as it approximates CDM on large scales ($${\gtrsim}1$$ Mpc) while potentially resolving some of its small-scale problems via kiloparsec-scale quantum interference. However, the most basic FDM model, with one free parameter (the boson mass), is subject to a tension: small boson masses yield the desired cores of dwarf galaxies but underpredict structure in the Lyman-α forest, while large boson masses render FDM effectively identical to CDM. This Catch-22 problem may be alleviated by considering an axion-like particle with attractive particle self-interactions. We simulate an idealized FDM halo with self-interactions parametrized by an energy decay constant $$f \sim 10^{15}~\rm {GeV}$$ related to the axion symmetry-breaking conjectured to solve the strong-CP problem in particle physics. We observe solitons, a hallmark of FDM, condensing within a broader halo envelope, and find that the density profile and soliton mass depend on self-interaction strength. We propose generalized formulae to extend those from previous works to include self-interactions. We also investigate a critical mass threshold predicted for strong interactions at which the soliton collapses into a compact, unresolved state. We find that the collapse happens quickly, and its effects are initially contained to the central region of the halo.  more » « less
Award ID(s):
2108962 1910346 1752913
PAR ID:
10537072
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Oxford University Press
Date Published:
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
533
Issue:
2
ISSN:
0035-8711
Format(s):
Medium: X Size: p. 2454-2472
Size(s):
p. 2454-2472
Sponsoring Org:
National Science Foundation
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