{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/evolution-of-self-gravitating-spherical-dark","title":"Evolution of self-gravitating spherical dark-matter halos with and without new physics","arxiv_id":"2504.13996","date":"2025-04-18","proceeding":null,"authors":["Marc Kamionkowski","Kris R. Sigurdson"],"abstract":"We present an efficient numerical algorithm for evolving self-gravitating systems of dark-matter particles that leverages the assumption of spherical symmetry to reduce the nominally six-dimensional phase space to three dimensions. It can be used to quickly determine numerically the evolution of an initially static stable self-consistent self-gravitating system if there is some additional or new physics. We illustrate here with four examples: (1) the effects of the growth of a supermassive black hole at the center; (2) the effects of stripping of the outer layers of the halo (a toy model for the effects of tidal stripping of galaxies); (3) the response of a self-gravitating system to dark matter that decays to a slightly less massive state; and (4) the effects of a slow change to Newton's constant. The approach can be extended to study dark matter with elastic and inelastic self-interactions and to study the process of virialization in spherical collapse. We describe some aspects of a code NSphere that implements this approach which we are making available.","url_abs":"https://arxiv.org/abs/2504.13996v1","url_pdf":"https://arxiv.org/pdf/2504.13996v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"evolution-of-self-gravitating-spherical-dark","repo_url":"https://github.com/kris-sigurdson/nsphere","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null},{"paper_slug":"evolution-of-self-gravitating-spherical-dark","repo_url":"https://github.com/nsphere-sidm/nsphere-sidm","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}