Cosmic structure as the quantum interference of a coherent dark wave

By Hsi-Yu Schive, Tzihong Chiueh, T. Broadhurst. Nature Physics, 2014

804 citations recorded by the source corpus.

A cosmological model treating dark matter as a coherent quantum wave agrees well with conventional dark-matter theory on an astronomical scale. But on smaller scales, the quantum nature of wave-like dark matter can explain dark-matter cores that are observed in dwarf galaxies, which standard theory cannot. The conventional cold-particle interpretation of dark matter (known as ‘cold dark matter’, or CDM) still lacks laboratory support and struggles with the basic properties of common dwarf galaxies, which have surprisingly uniform central masses and shallow density profiles1,2,3,4,5. In contrast, galaxies predicted by CDM extend to much lower masses, with steeper, singular profiles6,7,8,9. This tension motivates cold, wavelike dark matter (ψDM) composed of a non-relativistic Bose–Einstein condensate, so the uncertainty principle counters gravity below a Jeans scale10,11,12. Here we achieve cosmological simulations of this quantum state at unprecedentedly high resolution capable of resolving dwarf galaxies, with only one free parameter, mB, the boson mass. We demonstrate the large-scale structure is indistinguishable from CDM, as desired, but differs radically inside galaxies where quantum interference forms solitonic cores surrounded by extended haloes of fluctuating density granules. These results allow us to determine eV using stellar phase-space distributions in dwarf spheroidal galaxies. Denser, more massive solitons are predicted for Milky Way sized galaxies, providing a substantial seed to help explain early spheroid formation. The onset of galaxy formation is substantially delayed relative to CDM, appearing at redshift z ≲ 13 in our simulations.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/c9574b6f3a33c09750870dd2f95e6488a32354ae

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Citations in the corpus

CMB-S4 Science Case, Reference Design, and Project Plan (2019, result): “Realizing this sensitivity will require better modeling of the non-linear clustering of axions [315], building upon and applying the results of previous work [316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332].”
The landscape of QCD axion models (2020, background): “The typical mass of the axion star is fixed once a formation mechanism is imposed [344, 345].”
Black hole formation from axion stars (2016, background): “3), galaxies are expected to host axion stars at their cores [16] (for sufficiently low axion mass such that the axion stars are large and not disrupted by repeated mergers).”
Constraining the mass of light bosonic dark matter using SDSS Lyman-α forest (2017, methodology): “…regime i.e. at low redshifts and reasonably small scale, the evolution of the FDM fluid can be rigorously followed using two equivalent methods : either by explicitly solving the PoissonSchrödinger equations as in Schive et al. (2014), or by solving the corresponding Madelung fluid equations.”
Gravitational probes of dark matter physics (2017, background): “(43) With mF in the range of 10 6 − 1011 GeV, the gravitino masses can range from ∼ 100 eV up to 100 TeV.”
Small scale problems of the $\Lambda$CDM model: a short review (2016, background): “Such non-relativistic Bose condensate was recently simulated for structure formation [352], where large scale structures could not distinguish CDM universes from their model, while flat density profiles and reduced small scale substructures resulted from the opposition, at small scales, between grav”
Ultralight scalars as cosmological dark matter (2016, background): “This process is sometimes called “gravitational cooling” [45, 56–58], and the wavy granularity that is the source of this relaxation is seen clearly in simulations [16].”
Axion dark matter, solitons and the cusp–core problem (2015, methodology): “Schive et al. (2014a) solved the system of ODEs in equation (3) using the shooting method and the boundary conditions of Guzmán & Ureña-López (2006): φ(0) = ∂rφ(0) = 0, (A49) φ(r → ∞) = 0, (A50)”