N-body simulations of dark matter-baryon interactions

Abstract

Dark matter (DM) particles can interact with particles of the standard model. Although there are a number of constraints derived from direct and indirect detection experiments, the evolution of astrophysical objects could offer a promising probe. Obtaining predictions is challenging and primarily limited by our ability to simulate scattering between DM and baryonic particles within N-body and hydrodynamics simulations. We have developed the first scheme allowing for the simulation of these interacting dark matter (IDM) models, accurately accounting for their angular and velocity dependence, as well as the mass ratio between the DM and baryonic scattering partners. To describe DM-baryon interactions, we used an N-body code together with its implementation of smoothed-particle hydrodynamics and meshless finite mass. The interaction is realised in a pairwise fashion by creating a virtual scattering partner from the baryonic particle and allowing it to interact with a DM particle using a scattering routine initially developed for self-interacting dark matter (SIDM). After the interaction, the virtual particle is rejoined with the baryonic particle, fulfilling the requirements of energy and momentum conservation. Through several test problems, we demonstrated that we are able to reproduce the analytic solutions with our IDM scheme. This includes a test for scattering with a physical mass ratio of 1:1000, which is beyond the limits of SIDM simulations. We comment on various numerical aspects and challenges, and we describe the limitations of our numerical scheme. Furthermore, we study the impact of IDM on halo formation with a collapsing over-density. We find that it is possible to accurately model IDM within N-body and hydrodynamics simulations commonly used in astrophysics. Finally, our scheme allows for novel predictions to be made and new constraints on DM-baryon scattering to be set.

18 pages, 16 figures + appendices, accepted for publication in A&A

References in corpus (22)

• Array Programming with NumPy
• Dwarf galaxies in CDM and SIDM with baryons: observational probes of the nature of dark matter
• Cosmological Constraints on Dark Matter Interactions with Ordinary Matter
• Energy equipartition between stellar and dark matter particles in cosmological simulations results in spurious growth of galaxy sizes
• Review on Smoothed Particle Hydrodynamics: Methodology development and recent achievement
• Gravothermal evolution of dark matter halos with differential elastic scattering
• Gravothermal solutions of SIDM halos: mapping from constant to velocity-dependent cross section
• The Cosmological Simulation Code OpenGadget3 -- Implementation of Meshless Finite Mass
• $S_8$ Tension in the Context of Dark Matter-Baryon Scattering
• Dianoga SIDM: galaxy cluster self-interacting dark matter simulations
• Cosmological and idealized simulations of dark matter haloes with velocity-dependent, rare and frequent self-interactions
• Constraints on Dark Matter-Electron Scattering from Molecular Cloud Ionization
• Introducing the AIDA-TNG project: galaxy formation in alternative dark matter models
• Numerical challenges for energy conservation in N-body simulations of collapsing self-interacting dark matter halos
• The role of baryons in self-interacting dark matter mergers
• Dark matter coupled to radiation: Limits from the Milky Way satellites
• Simulations of galaxy cluster mergers with velocity-dependent, rare and frequent self-interactions
• Exact treatment of weak dark matter-baryon scattering for linear-cosmology observables
• Bounds on Velocity-Dependent Dark Matter-Baryon Scattering from Large-Scale Structure
• COZMIC. II. Cosmological Zoom-in Simulations with Fractional non-CDM Initial Conditions
• Weak Lensing Constraints on Dark Matter-Baryon Interactions with $N$-Body Simulations and Machine Learning
• Simulating realistic self-interacting dark matter models including small and large-angle scattering

Cited by in corpus (4)

• Forecasting 21-cm power spectrum sensitivity to dark Matter-baryon scattering
• Merging Galaxy Clusters and the Search for New Physics of Dark Matter: A Review
• A New Method to Simulate Dark Matter-Baryon Interactions and Application to an Isolated Disk Galaxy
• Particle loads for cosmological simulations with equal-mass dark matter and baryonic particles