Halo formation and evolution in scalar field dark matter and cold dark matter: New insights from the fluid approach

Abstract

(abridged) We present simulations of halo formation and evolution in scalar field dark matter (SFDM) cosmologies in the Thomas-Fermi regime, aka ``SFDM-TF", where a strong repulsive 2-particle self-interaction (SI) is included, being a valuable alternative to CDM, with the potential to resolve its ``cusp-core" problem. In general, SFDM behaves like a quantum fluid. Previous literature has presented two fluid approximations for SFDM-TF, as well as simulations of halo formation. These results confirmed earlier expectations and are generally in mutual agreement, but discrepancies were also reported. Therefore, we perform dedicated 3D cosmological simulations for the SFDM-TF model, applying both fluid approximations, as well as for CDM. Our results are very well in accordance with previous works and extend upon them, in that we can explain the reported discrepancies as a result of different simulation setups. We find some interesting details: The evolution of both SFDM-TF and CDM halos follows a 2-stage process. In the early stage, the density profile in the center becomes close to a $(n=1.5)$-polytropic core, dominated by an "effective" velocity-dispersion pressure $P_{\sigma }$ which is common to both dark matter models. Consecutively, for CDM halos, the core transitions into a central cusp. In SFDM-TF halos, the additional pressure $P_{\text{SI}}$ due to SI determines the second stage of the evolution, where the central region follows closely a $(n=1)$-polytropic core, embedded in a nearly isothermal envelope, i.e. the outskirts are similar to CDM. We also encounter a new effect, namely a late-time expansion of both polytropic core plus envelope, because the size of the almost isothermal halo envelope is affected by the expansion of the background universe. So, an initial primordial core of $\sim 100$ pc can evolve into a larger core of $\gtrsim 1$ kpc, even without feedback from baryons.

arXiv commentfinal version; 26 pages, 16 figures

References in corpus (32)

• The Structure of Cold Dark Matter Halos
• A direct empirical proof of the existence of dark matter
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• A Multi-Code Analysis Toolkit for Astrophysical Simulation Data
• Concentrations of Dark Halos from their Assembly Histories
• MultiDark simulations: the story of dark matter halo concentrations and density profiles
• Multi-scale initial conditions for cosmological simulations
• Understanding the Core-Halo Relation of Quantum Wave Dark Matter, $\psi$DM, from 3D Simulations
• Can dark matter be a Bose-Einstein condensate?
• Fluid Dark Matter
• Repulsive Dark Matter
• Simulations of solitonic core mergers in ultra-light axion dark matter cosmologies
• Mass and shape of the Milky Way's dark matter halo with globular clusters from Gaia and Hubble
• Evolution of the Schrödinger--Newton system for a self--gravitating scalar field
• Contrasting Galaxy Formation from Quantum Wave Dark Matter, $\psi$DM, with $\Lambda$CDM, using Planck and Hubble Data
• Angular Momentum and Vortex Formation in Bose-Einstein-Condensed Cold Dark Matter Haloes
• Gravothermal collapse of isolated self-interacting dark matter haloes: N-body simulation versus the fluid model
• Structure formation in large-volume cosmological simulations of fuzzy dark matter: Impact of the non-linear dynamics
• Newtonian Collapse of Scalar Field Dark Matter
• Galaxy Formation with BECDM -- II. Cosmic Filaments and First Galaxies
• Formation and Evolution of the Self-Interacting Dark Matter Halos
• Rotation curves of high-resolution LSB and SPARC galaxies with fuzzy and multistate (ultra-light boson) scalar field dark matter
• A Convenient Set of Comoving Cosmological Variables and Their Application
• Complex scalar field dark matter on galactic scales
• Core-Envelope Haloes in Scalar Field Dark Matter with Repulsive Self-Interaction: Fluid Dynamics Beyond the de Broglie Wavelength
• Self Similar Spherical Collapse Revisited: a Comparison between Gas and Dark Matter Dynamics
• Cosmological structure formation in scalar field dark matter with repulsive self-interaction: The Incredible Shrinking Jeans Mass
• Constraints on self-interacting Bose-Einstein condensate dark matter using large-scale observables
• Cosmological simulations of self-interacting Bose-Einstein condensate dark matter
• Scalar Field Dark Matter mass model and evolution of rotation curves for Lsb galaxies
• One-Dimensional Fuzzy Dark Matter Models: Structure Growth and Asymptotic Dynamics

Cited by in corpus (5)

• Kinetic relaxation and nucleation of Bose stars in self-interacting wave dark matter
• Single and merger soliton dynamics in scalar field dark matter with and without self-interactions
• Dark matter halos modeled by polytropic spheres influenced by the relict cosmological constant and trapping polytropes forming supermassive black holes
• Field equation of thermodynamic gravity and galactic rotational curves
• Core-halo scaling relations in self-interacting scalar field dark matter