Testing the isothermal Jeans model for self-interacting dark matter halos in the collapse phase

TL;DR

This study evaluates the isothermal Jeans model's accuracy in predicting the evolution of self-interacting dark matter halos during collapse, showing it is reliable and efficient compared to detailed simulations.

Contribution

It benchmarks the semi-analytical isothermal Jeans model against high-resolution simulations, demonstrating its effectiveness in modeling SIDM halo collapse.

Findings

The model accurately reproduces density evolution during most of the collapse.

It does not capture the sharp increase in central velocity dispersion.

The Jeans model closely tracks lensing observables in deep collapse regimes.

Abstract

We benchmark the semi-analytical isothermal Jeans model against a high-resolution isolated N-body simulation that follows a self-interacting dark matter (SIDM) halo into deep core collapse. The model accurately reproduces the density evolution through much of the collapse phase, although it does not capture the sharp rise in central velocity dispersion during collapse. When applied to strong gravitational lensing observables, such as the projected mass and logarithmic density slope of SIDM halos, the Jeans model tracks the simulated evolution more closely than the parametric approach in the deep collapse regime. Our results demonstrate that the isothermal Jeans model provides a reliable and computationally efficient description of SIDM halo evolution.