Semi-Analytic Predictions for Strong-Lensing Perturbers in Cold and Self-Interacting Dark Matter
Abstract
Strong gravitational lensing is sensitive to the abundance and internal structure of dark matter halos, providing a probe of gravothermal evolution in self-interacting dark matter (SIDM). We combine semi-analytic cold dark matter (CDM) subhalo histories with a model for gravothermal evolution in SIDM to generate CDM and SIDM subhalo populations across SIDM parameter space. We predict their projected enclosed masses and deflection-based projected density slopes and compare them with three perturbers inferred through gravitational imaging in PJ011646, SDSS J0946+1006, and JVAS B1938+666. For SIDM model parameters σ0/mχ=147.1 cm2/g and w=120 km/s, SIDM subhalos reproduce all three perturbers more often than CDM subhalos. For PJ011646, we find ~0.6 cored SIDM subhalos per host matching the perturber, compared with ~0.002 in CDM, while core-collapsed subhalos are too steep. For SDSS J0946+1006, we find ~3 core-collapsed and ~0.004 cored SIDM subhalos per host, compared with none in 900 CDM realizations, although baryons, neglected here, may matter for such massive subhalos. For "detection V" in JVAS B1938+666, we find ~220 core-collapsed and ~20 cored SIDM subhalos per host within the 2σ posterior region, compared with ~0.2 in CDM; the CDM candidates require exceptionally early accretion, at median redshift z∼13. Simultaneously reproducing all three perturbers requires w≳102 km/s, so that the massive (~5.6×1010M⊙) progenitors of SDSS J0946+1006 candidates can collapse, and is achieved for σ0/mχ≳102 cm2/g in the parameter sets studied. Our results show how semi-analytic models can quantify how often subhalos reproduce individual perturbers in different dark matter models, and our modular framework can be readily updated as models of tidal stripping and late-stage gravothermal evolution in SIDM improve. (abridged)
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BibTeX
@misc{tekverk2026semianalytic,
title = {{Semi-Analytic Predictions for Strong-Lensing Perturbers in Cold and Self-Interacting Dark Matter}},
author = {Jonathan Tekverk and Duncan K. Adams and Simon Birrer and Rouven Essig and Daniel Gilman},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.31881},
eprint = {2610.31881},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.31881},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Semi-Analytic Predictions for Strong-Lensing Perturbers in Cold and Self-Interacting Dark Matter
AU - Jonathan Tekverk
AU - Duncan K. Adams
AU - Simon Birrer
AU - Rouven Essig
AU - Daniel Gilman
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.31881
UR - https://arxiv.org/abs/2610.31881
AB - Strong gravitational lensing is sensitive to the abundance and internal structure of dark matter halos, providing a probe of gravothermal evolution in self-interacting dark matter (SIDM). We combine semi-analytic cold dark matter (CDM) subhalo histories with a model for gravothermal evolution in SIDM to generate CDM and SIDM subhalo populations across SIDM parameter space. We predict their projected enclosed masses and deflection-based projected density slopes and compare them with three perturbers inferred through gravitational imaging in PJ011646, SDSS J0946+1006, and JVAS B1938+666. For SIDM model parameters σ_0/m_χ=147.1 cm^2/g and w=120 km/s, SIDM subhalos reproduce all three perturbers more often than CDM subhalos. For PJ011646, we find ~0.6 cored SIDM subhalos per host matching the perturber, compared with ~0.002 in CDM, while core-collapsed subhalos are too steep. For SDSS J0946+1006, we find ~3 core-collapsed and ~0.004 cored SIDM subhalos per host, compared with none in 900 CDM realizations, although baryons, neglected here, may matter for such massive subhalos. For "detection V" in JVAS B1938+666, we find ~220 core-collapsed and ~20 cored SIDM subhalos per host within the 2σ posterior region, compared with ~0.2 in CDM; the CDM candidates require exceptionally early accretion, at median redshift z∼13. Simultaneously reproducing all three perturbers requires w≳10^2 km/s, so that the massive (~5.6×10^10M_⊙) progenitors of SDSS J0946+1006 candidates can collapse, and is achieved for σ_0/m_χ≳10^2 cm^2/g in the parameter sets studied. Our results show how semi-analytic models can quantify how often subhalos reproduce individual perturbers in different dark matter models, and our modular framework can be readily updated as models of tidal stripping and late-stage gravothermal evolution in SIDM improve. (abridged)
ER -