HSI-YU SCHIVETZI-HONG CHIUEHChiueh, TzihongTzihongChiueh2019-12-202019-12-2020180035-8711https://scholars.lib.ntu.edu.tw/handle/123456789/436982https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042120444&doi=10.1093%2fmnrasl%2fslx159&partnerID=40&md5=90382b27008af100ce9a59f3af11873bWave dark matter (ψDM) composed of extremely light bosons (mψ ∼ 10−22 eV), with quantum pressure suppressing structures below a kpc-scale de Broglie wavelength, has become a viable dark matter candidate. Compared to the conventional free-particle ψDM (FPψDM), the extreme-axion ψDM model (EAψDM) proposed by Zhang & Chiueh features a larger cut-off wavenumber and a broad spectral bump in the matter transfer function. Here, we conduct cosmological simulations to compare the halo abundances and assembly histories at z = 4-11 between three different scenarios: FPψDM, EAψDM and cold dark matter (CDM). We show that EAψDM produces significantly more abundant low-mass haloes than FPψDM with the same mψ, and therefore could alleviate the tension in mψ required by the Lyα forest data and by the kpc-scale dwarf galaxy cores. We also find that, compared to the CDM counterparts, massive EAψDM haloes are, on average, 3-4 times more massive at z = 10-11 due to their earlier formation, undergo a slower mass accretion at 7 ≲ z ≲ 11, and then show a rapidly rising major merger rate exceeding CDM by ∼50 per cent at 4 ≲ z ≲ 7. This fact suggests that EAψDM haloes may exhibit more prominent starbursts at z ≲ 7. © 2017 The AuthorsDark matter; Galaxies: evolution; Galaxies: high-redshift; Galaxies: luminosity function; Mass function[SDGs]SDG15journal article10.1093/mnrasl/slx15923111522000;35373583000;WOS:000438220800008