{"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/cmb-hd-as-a-probe-of-dark-matter-on-sub","title":"CMB-HD as a Probe of Dark Matter on Sub-Galactic Scales","arxiv_id":"2405.12220","date":"2024-05-20","proceeding":null,"authors":["Amanda MacInnis","Neelima Sehgal"],"abstract":"We show for the first time that high-resolution CMB lensing observations can probe structure on sub-galactic scales. In particular, a CMB-HD experiment can probe out to k ~ 55 h/Mpc, corresponding to halo masses of about $10^8 M_{\\odot}$. Over the range 0.005 h/Mpc < k < 55 h/Mpc, spanning four orders of magnitude, the total lensing signal-to-noise ratio (SNR) from the temperature, polarization, and lensing power spectra is greater than 1900. CMB-HD gains most of the lensing SNR at small scales from the temperature power spectrum, as opposed to the lensing spectrum. These lensing measurements allow CMB-HD to distinguish between cold dark matter (CDM) and non-CDM models that change the matter power spectrum on sub-galactic scales. We also find that CMB-HD can distinguish between baryonic feedback effects and non-CDM models due to the different way each impacts the lensing signal. The kinetic Sunyaev-Zel'dovich (kSZ) power spectrum further constrains non-CDM models that deviate from CDM on the smallest scales CMB-HD measures. For example, CMB-HD can detect 1 keV warm dark matter (WDM) at 30$\\sigma$, or rule out about 7 keV WDM at 95% CL, in a $\\Lambda$WDM + $N_{\\rm{eff}} + \\sum m_\\nu + m_{\\rm{WDM}} + \\log_{10}T_{\\rm{AGN}} + A_{\\rm{kSZ}} + n_{\\rm{kSZ}}$ model; here $T_{\\rm{AGN}}$ characterizes the strength of the feedback, and $A_{\\rm{kSZ}}$ and $n_{\\rm{kSZ}}$ allow freedom in the amplitude and slope of the kinetic Sunyaev-Zel'dovich power spectrum. This work provides an initial exploration of what can be achieved with reasonable assumptions about systematic effects. We make the CMB-HD Fisher code used here publicly available, and note that it can be modified to use any non-CDM model that changes the matter power spectrum.","url_abs":"https://arxiv.org/abs/2405.12220v3","url_pdf":"https://arxiv.org/pdf/2405.12220v3.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":"cmb-hd-as-a-probe-of-dark-matter-on-sub","repo_url":"https://github.com/cmb-hd/hdpk","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}