Title: SIDM as a Controlled Deformation of CDM Halo Evolution Paths

Speaker: Daneng Yang 杨大能 (Purple Mountain Observatory, Chinese Academy of Sciences)

Time: 1:30 pm, Nov 10 (Tuesday), 2026

Venue: Physics Building W260

Abstract: Self-interacting dark matter (SIDM) can substantially reshape dark matter halos through accumulated particle scatterings, driving core formation and, in some cases, gravothermal core collapse. Predicting these effects in realistic environments requires accounting for the diverse assembly histories of dark matter halos. In this talk, I will present our recent efforts to model SIDM as a controlled deformation of cold dark matter (CDM) halo evolution paths. We combine cosmological CDM simulations, controlled SIDM simulations, and a parametric model of gravothermal evolution to separate the effects of self-interactions from halo assembly and environmental processes. By integrating SIDM effects along CDM assembly histories, we demonstrate that a two-component SIDM model can simultaneously explain compact strong-lensing perturbers, enhanced galaxy–galaxy strong lensing in clusters, and dwarf galaxy clustering patterns. I will also discuss an endothermic inelastic dark matter interpretation of the recently reported mass-dependent dark matter deficit in galaxies, using a complementary simulation approach. These studies illustrate how theoretical modeling connects particle-level interactions to observable small-scale structures and enables systematic tests of SIDM models.

Bio: Daneng Yang is currently an Associate Research Professor at Purple Mountain Observatory, CAS. He received his Ph.D. and bachelor's degree from Peking University. He previously conducted postdoctoral research at Tsinghua University and the University of California, Riverside. In recent years, his research has focused on the distribution of dark matter in the universe and its associated new-physics signatures. As of October 2026, he has published 40 SCI papers, including 13 as first author.