Self-Interacting Dark Matter with Mass Segregation: A Unified Explanation of Dwarf Cores and Small-Scale Lenses

Abstract

In two-component self-interacting dark matter (SIDM) models with inter-species interactions, mass segregation arises naturally from collisional relaxation, enhancing central densities and gravothermal evolution. We demonstrate that models with velocity-dependent interactions, both within and between species, can connect several small-scale observations while remaining consistent with cluster-scale constraints. This combination enables core formation in dwarf halos, where the presence of baryons increases the inner densities and enhances the predicted strong lensing signatures. Using cosmological and controlled simulations alongside an accurate parametric model, we present proof-of-principle examples showing that this framework can explain the structure of dark perturbers observed in strong lensing systems, and can enhance the efficiency of small-scale lenses by a factor of a few, in line with the excess reported in galaxy-galaxy strong-lensing observations. Importantly, mass segregation can enhance the Einstein radii of SIDM halos relative to their cold dark matter (CDM) counterparts, overcoming a key challenge in one-component SIDM scenarios. Our results present mass segregation in two-component SIDM as a self-consistent, testable framework with the potential to address multiple small-scale challenges in structure formation.

18 pages, 12 figures. Version 3, matched to the published version in Science Bulletin. In version two, we: (1) introduce a parametric model for two-component SIDM that accounts for mass segregation; (2) provide a new discussion of baryonic effects; (3) include a statistical interpretation of the GGSL signal; and (4) demonstrate the numerical robustness of our analysis

References in corpus (61)

• A Universal Density Profile from Hierarchical Clustering
• The cosmological simulation code GADGET-2
• Observational evidence for self-interacting cold dark matter
• GADGET: A code for collisionless and gasdynamical cosmological simulations
• Small-Scale Challenges to the $\Lambda$CDM Paradigm
• The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores
• Galactic star formation and accretion histories from matching galaxies to dark matter haloes
• Dark Matter Self-interactions and Small Scale Structure
• The Inner Structure of LambdaCDM Halos I: A Numerical Convergence Study
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• Gravitationally Consistent Halo Catalogs and Merger Trees for Precision Cosmology
• The cored distribution of dark matter in spiral galaxies
• Dark Matter Halos as Particle Colliders: A Unified Solution to Small-Scale Structure Puzzles from Dwarfs to Clusters
• Gravitational detection of a low-mass dark satellite at cosmological distance
• Detection of lensing substructure using ALMA observations of the dusty galaxy SDP.81
• Detection of a Dark Substructure through Gravitational Imaging
• Bayesian Strong Gravitational-Lens Modeling on Adaptive Grids: Objective Detection of Mass Substructure in Galaxies
• The distribution of dark matter in galaxies
• Self-Interacting Dark Matter Halos and the Gravothermal Catastrophe
• The Spur and the Gap in GD-1: Dynamical evidence for a dark substructure in the Milky Way halo
• Can Feedback Solve the Too Big to Fail Problem?
• The Formation of Ultra Diffuse Galaxies in Cored Dark Matter Halos Through Tidal Stripping and Heating
• An excess of small-scale gravitational lenses observed in galaxy clusters
• Observable tests of self-interacting dark matter in galaxy clusters: cosmological simulations with SIDM and baryons
• Constraining Dissipative Dark Matter Self-Interactions
• Baryonic clues to the puzzling diversity of dwarf galaxy rotation curves
• A trail of dark matter-free galaxies from a bullet dwarf collision
• Strong lensing signatures of self-interacting dark matter in low-mass halos
• Core-collapse, evaporation and tidal effects: the life story of a self-interacting dark matter subhalo
• The Onset of Gravothermal Core Collapse in Velocity Dependent Self-Interacting Dark Matter Subhaloes
• Visible and dark matter from a first-order phase transition in a baryon-symmetric universe
• The interplay of Self-Interacting Dark Matter and baryons in shaping the halo evolution
• A Self-interacting Dark Matter Solution to the Extreme Diversity of Low-mass Halo Properties
• Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way
• Self-Interacting Dark Matter and Small-Scale Gravitational Lenses in Galaxy Clusters
• Universal gravothermal evolution of isolated self-interacting dark matter halos for velocity-dependent cross sections
• Motivations for a Large Self-Interacting Dark Matter Cross Section from Milky Way Satellites
• A persistent excess of galaxy-galaxy strong lensing observed in galaxy clusters
• The probability of galaxy-galaxy strong lensing events in hydrodynamical simulations of galaxy clusters
• Detecting Dark Matter Cores in Galaxy Clusters with Strong Lensing
• N-body simulations of dark matter with frequent self-interactions
• Gravitational imaging through a triple source plane lens: revisiting the $\Lambda$CDM-defying dark subhalo in SDSSJ0946+1006
• The impact of baryonic potentials on the gravothermal evolution of self-interacting dark matter haloes
• A Parametric Model for Self-Interacting Dark Matter Halos
• Dianoga SIDM: galaxy cluster self-interacting dark matter simulations
• Strongly lensed cluster substructures are not in tension with $\Lambda$CDM
• Astrophysical Tests of Dark Matter Self-Interactions
• Self-interacting dark matter interpretation of Crater II
• Detecting low-mass haloes with strong gravitational lensing II: constraints on the density profiles of two detected subhaloes
• The galaxy-galaxy strong lensing cross-sections of simulated LCDM galaxy clusters
• Self-Interacting Dark Matter, Core Collapse and the Galaxy-Galaxy Strong Lensing Discrepancy
• Formation of the Little Red Dots from the Core-collapse of Self-interacting Dark Matter Halos
• Testing the parametric model for self-interacting dark matter using matched halos in cosmological simulations
• A million-solar-mass object detected at cosmological distance using gravitational imaging
• SIDM Concerto: Compilation and Data Release of Self-interacting Dark Matter Zoom-in Simulations
• Exploring Self-Interacting Dark Matter Halos with Diverse Baryonic Distributions: A Parametric Approach
• Unexpected clustering pattern in dwarf galaxies challenges formation models
• A Universal Analytic Model for Gravitational Lensing by Self-Interacting Dark Matter Halos
• Diversifying halo structures in two-component self-interacting dark matter models via mass segregation
• A dense dark matter core of the subhalo in the strong lensing system JVAS B1938+666
• The "Little Dark Dot": Evidence for Self-interacting Dark Matter in the Strong Lens SDSS J0946+1006?