Cosmic Structure as the Quantum Interference of a Coherent Dark Wave

TL;DR

This paper presents high-resolution cosmological simulations of wave-like dark matter, revealing distinct galactic structures and providing a new estimate for the boson mass, which could resolve issues faced by traditional dark matter models.

Contribution

First high-resolution cosmological simulations of $f{ extit{ extbf{ψ}}}$DM showing unique galactic interference patterns and solitonic cores, with a new boson mass estimate based on dwarf galaxy data.

Findings

Galaxies exhibit interference networks with solitonic cores.

Boson mass estimated at $(8.1^{+1.6}_{-1.7})\times 10^{-23}$ eV.

Galaxy formation delayed to $z\lesssim 13$ in $f{ extit{ extbf{ψ}}}$DM.

Abstract

The conventional cold, particle interpretation of dark matter (CDM) still lacks laboratory support and struggles with the basic properties of common dwarf galaxies, which have surprisingly uniform central masses and shallow density profiles. In contrast, galaxies predicted by CDM extend to much lower masses, with steeper, singular profiles. This tension motivates cold, wavelike dark matter ($\psi$DM) composed of a non-relativistic Bose-Einstein condensate, so the uncertainty principle counters gravity below a Jeans scale. Here we achieve the first cosmological simulations of this quantum state at unprecedentedly high resolution capable of resolving dwarf galaxies, with only one free parameter, $\bf{m_B}$, the boson mass. We demonstrate the large scale structure of this $\psi$DM simulation is indistinguishable from CDM, as desired, but differs radically inside galaxies. Connected filaments and collapsed haloes form a large interference network, with gravitationally self-bound solitonic cores inside every galaxy surrounded by extended haloes of fluctuating density granules. These results allow us to determine $\bf{m_B=(8.1^{+1.6}_{-1.7})\times 10^{-23}~eV}$ 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. Suppression of small structures means the onset of galaxy formation for $\psi$DM is substantially delayed relative to CDM, appearing at $\bf{z\lesssim 13}$ in our simulations.