{"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/constraints-on-dark-matter-dark-energy","title":"Constraints on Dark Matter-Dark Energy Scattering from ACT DR6 CMB Lensing","arxiv_id":"2402.08149","date":"2024-02-13","proceeding":null,"authors":["Alex Laguë","Fiona McCarthy","Mathew Madhavacheril","J. Colin Hill","Frank J. Qu"],"abstract":"The predicted present-day amplitude of matter fluctuations based on cosmic microwave background (CMB) anisotropy data has sometimes been found discrepant with more direct measurements of late-time structure. This has motivated many extensions to the standard cosmological model, including kinetic interactions between dark matter and dark energy that introduce a drag force slowing the growth of structure at late times. Exploring this scenario, we develop a model for quasi-linear scales in the matter power spectrum by calculating the critical overdensity in the presence of this interaction and a varying dark energy equation of state. We explicitly avoid modeling or interpretation of data on non-linear scales in this model (such as use of $\\Lambda$CDM-calibrated priors), which would require numerical simulations. We find that the presence of the drag force hinders halo formation, thus increasing the deviation from $\\Lambda$CDM in the mildly non-linear regime. We use CMB lensing observations from the sixth data release of the Atacama Cosmology Telescope up to $L=1250$ (in combination with Planck, Sloan Digital Sky Survey, and 6dFGS data) to derive the strongest constraints to date on the amplitude of the drag term, finding the dimensionless interaction strength $\\Gamma_\\mathrm{DMDE}/(H_0\\rho_\\mathrm{c})<0.831\\; (2.81)$ at the 68\\% (95\\%) confidence level. The inclusion of non-linear corrections improves our constraints by about 35\\% compared to linear theory. Our results do not exclude the best-fit values of $\\Gamma_\\mathrm{DMDE}$ found in previous studies using information from galaxy weak lensing, though we find no statistical preference for the dark matter-dark energy kinetic interactions over $\\Lambda$CDM. We implement our model in a publicly available fork of the Boltzmann code CLASS at https://github.com/fmccarthy/Class_DMDE.","url_abs":"https://arxiv.org/abs/2402.08149v1","url_pdf":"https://arxiv.org/pdf/2402.08149v1.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":"constraints-on-dark-matter-dark-energy","repo_url":"https://github.com/fmccarthy/class_dmde","is_official":1,"mentioned_in_paper":1,"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}