Testing the parametric model for self-interacting dark matter using matched halos in cosmological simulations

TL;DR

This paper evaluates a parametric SIDM halo model against high-resolution cosmological simulations, demonstrating its accuracy in predicting halo properties and its utility in small-scale structure studies.

Contribution

It provides a systematic validation of a SIDM halo model using matched halos from simulations, showing its effectiveness in capturing halo evolution and effects on lensing.

Findings

Model predictions agree within 10-50% for most halos.

Effective in capturing gravothermal evolution with velocity-dependent interactions.

Useful for small-scale structure analysis and lensing studies.

Abstract

We systemically evaluate the performance of the self-interacting dark matter (SIDM) halo model proposed in arXiv:2305.16176 with matched halos from high-resolution cosmological CDM and SIDM simulations. The model incorporates SIDM effects along mass evolution histories of CDM halos and it is applicable to both isolated halos and suhbhalos. We focus on the accuracy of the model in predicting halo density profiles at $z=0$ and the evolution of maximum circular velocity. We find the model predictions agree with the simulations within $10\%-50\%$ for most of the simulated (sub)halos, $50\%-100\%$ for extreme cases. This indicates that the model effectively captures the gravothermal evolution of the halos with very strong, velocity-dependent self-interactions. For an example application, we apply the model to study the impact of various SIDM scenarios on strong lensing perturber systems, demonstrating its utility in predicting SIDM effects for small-scale structure analyses. Our findings confirm that the model is an effective tool for mapping CDM halos into their SIDM counterparts.