Self-interactions facilitate inter-particle redistribution of energy within the dense regions of galactic halos, implying modifications in the density and velocity distribution of dark matter. Simulating dark-matter only isolated halos for a wide range of mass and specific self-scattering cross-sections, we make a systematic study of the impact of self-scattering on the velocity distribution profiles. We report a conservative bound on σ/m≤2.7cm2/gm at 95% C.L. from observations of rotation curves in Milky-Way size galaxies. Sub-leading bounds from LSB galaxy and clusters are also presented.
@article{arxiv.2505.10451,
title = {Constraints on dark matter self-interaction from velocity distribution function in isolated halos},
author = {Tirtha Sankar Ray and Sambo Sarkar},
journal= {arXiv preprint arXiv:2505.10451},
year = {2025}
}