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The newly established luminosity functions of high-z galaxies at $4 lesssim z lesssim 10$ can provide a stringent check on dark matter models that aim to explain the core properties of dwarf galaxies. The cores of dwarf spheroidal galaxies are understood to be too large to be accounted for by free streaming of warm dark matter without overly suppressing the formation of such galaxies. Here we demonstrate with cosmological simulations that wave dark matter, $psi$DM, appropriate for light bosons such as axions, does not suffer this problem, given a boson mass of $m_{psi} ge 1.2 times 10^{-22}{,rm eV}$ ($2sigma$). In this case, the halo mass function is suppressed below $sim 10^{10}{,M_odot}$ at a level that is consistent with the high-z luminosity functions, while simultaneously generating the kpc-scale cores in dwarf galaxies arising from the solitonic ground state in $psi$DM. We demonstrate that the reionization history in this scenario is consistent with the Thomson optical depth recently reported by Planck, assuming a reasonable ionizing photon production rate. We predict that the luminosity function should turn over slowly around an intrinsic UV luminosity of $M_{rm UV} gtrsim -16$ at $z gtrsim 4$. We also show that for galaxies magnified $mathord{>}10times$ in the Hubble Frontier Fields, $psi$DM predicts an order of magnitude fewer detections than cold dark matter at $z gtrsim 10$ down to $M_{rm UV} sim -15$, allowing us to distinguish between these very different interpretations for the observed coldness of dark matter.
We examine the nonlinear structure of gravitationally collapsed objects that form in our simulations of wavelike cold dark matter ($psi$DM), described by the Schr{o}dinger-Poisson (SP) equation with a particle mass $sim 10^{-22} {rm eV}$. A distinct
Surveying dark matter deficient galaxies (those with dark matter mass to stellar mass ratio $M_{rm dm}/M_{rm star}<1$) in the Illustris simulation of structure formation in the flat-$Lambda$CDM cosmogony, we find $M_{rm star} approx 2 times 10^8, M_s
We present predictions for the outcome of deep galaxy surveys with the $James$ $Webb$ $Space$ $Telescope$ ($JWST$) obtained from a physical model of galaxy formation in $Lambda$CDM. We use the latest version of the GALFORM model, embedded within a ne
We study the impact of a warm dark matter (WDM) cosmology on dwarf galaxy formation through a suite of cosmological hydrodynamical zoom-in simulations of $M_{rm halo} approx10^{10},M_{odot}$ dark matter halos as part of the Feedback in Realistic Envi
The leading tensions to the collisionless cold dark matter (CDM) paradigm are the small-scale controversies, discrepancies between observations at the dwarf-galactic scale and their simulational counterparts. In this work we consider methods to infer