{"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/predictions-for-measuring-the-21-cm-multi","title":"Predictions for measuring the 21-cm multi-frequency angular power spectrum using SKA-Low","arxiv_id":"1910.05196","date":"2019-10-11","proceeding":null,"authors":["Rajesh Mondal","Abinash Kumar Shaw","Ilian T. Iliev","Somnath Bharadwaj","Kanan K. Datta","Suman Majumdar","Anjan K. Sarkar","Keri L. Dixon"],"abstract":"The light-cone (LC) effect causes the mean as well as the statistical properties of the redshifted 21-cm signal $T_{\\rm b}(\\hat{\\bf n},\\nu)$ to change with frequency $\\nu$ (or cosmic time). Consequently, the statistical homogeneity (ergodicity) of the signal along the line of sight (LoS) direction is broken. This is a severe problem particularly during the Epoch of Reionization (EoR) when the mean neutral hydrogen fraction ($\\bar{x}_{\\rm HI}$) changes rapidly as the universe evolves. This will also pose complications for large bandwidth observations. These effects imply that the 3D power spectrum $P(k)$ fails to quantify the entire second-order statistics of the signal as it assumes the signal to be ergodic and periodic along the LoS. As a proper alternative to $P(k)$, we use the multi-frequency angular power spectrum (MAPS) ${\\mathcal C}_{\\ell}(\\nu_1,\\nu_2)$ which does not assume the signal to be ergodic and periodic along the LoS. Here, we study the prospects for measuring the EoR 21-cm MAPS using future observations with the upcoming SKA-Low. Ignoring any contribution from the foregrounds, we find that the EoR 21-cm MAPS can be measured at a confidence level $\\ge 5\\sigma$ at angular scales $\\ell \\sim 1300$ for total observation time $t_{\\rm obs} \\ge 128\\,{\\rm hrs}$ across $\\sim 44\\,{\\rm MHz}$ observational bandwidth. We also quantitatively address the effects of foregrounds on MAPS detectability forecast by avoiding signal contained within the foreground wedge in $(k_\\perp, k_\\parallel)$ plane. These results are very relevant for the upcoming large bandwidth EoR experiments as previous predictions were all restricted to individually analyzing the signal over small frequency (or equivalently redshift) intervals.","url_abs":"http://arxiv.org/abs/1910.05196v2","url_pdf":"http://arxiv.org/pdf/1910.05196v2.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":"predictions-for-measuring-the-21-cm-multi","repo_url":"https://github.com/rajeshmondal18/MAPS","is_official":1,"mentioned_in_paper":0,"mentioned_in_github":0,"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}