Year: 2026
Type: preprint
Abstract: The cosmological distribution of neutral hydrogen (HI) during the post-reionization era is highly non-Gaussian due to the underlying non-linear structure formation, complex galaxy biasing, and potential primordial non-Gaussianity. One needs higher-order (beyond two-point) statistics to maximally extract the non-Gaussian information out of the 21-cm intensity maps. This chapter summarizes the potential of several higher-order statistics, including voxel intensity distribution, emission line stacking, probability density functions, $\ell_1$-norm, bispectrum, and various marked statistics. Additionally, image-based morphological descriptors, such as the Largest Cluster Statistic, local dimensions, and Minkowski functionals, etc., can potentially characterize the morphology and geometry of the cosmic web encoded in the 21-cm intensity maps. This chapter presents forecasts of the detectability of these higher-order statistics in the context of the future SKAO observations. These forecasts incorporate instrumental noise, observational effects, and, in some cases, foreground removal in their analyses. With its unprecedented sensitivity, the future SKAO 21-cm observations will enable us to measure these higher-order statistics more precisely, possibly helping to break degeneracies between astrophysical and cosmological parameters, and maximizing the science outcome from these surveys.
Source: arXiv (Cornell University)
Authors: Majumdar, Suman, Sarkar, Debanjan, Noble, Leon, Dosibhatla, Manas Mohit, Chen, Zhaoting, Vos-Ginés, Bernhard, Pandya, Vishrut, Kamran, Mohd, Pal, Sourav, Murmu, Chandra Shekhar, Uhlemann, Cora, Gorbatchev, Pauline, Starck, Jean-Luc, Bernal, José Luis, Spinelli, Marta, Heneka, Caroline S., Viel, Matteo, De Lucia, Gabriella, Fontanot, Fabio, Camera, Stefano, Cunnington, Steve, Spina, Benedetta, Karagiannis, Dionysis, Pal, Samit Kumar, Tripathi, Anshuman, Libanore, Sarah, Shaw, Abinash Kumar, Mondal, Rajesh, Mahida, Yashrajsinh, Akrami, Yashar, Bull, Philip, Clarkson, Chris, Datta, Abhirup, Fonseca, José, Ma, Yin-Zhe, Maartens, Roy, Randrianjanahary, Liantsoa F., Sahlen, Martin, Wang, Xin, Wang, Yougang, Weller, Jochen
Institutions: Indian Institute of Technology Indore, Trottier Space Institute at McGill, McGill University, Royal Observatory, University of Edinburgh, Bielefeld University, Trieste Astronomical Observatory, Indian Statistical Institute, Open University of Israel, University of Crete, Foundation for Research and Technology Hellas, Centre National de la Recherche Scientifique, Université Paris Cité, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Astrophysique, Instrumentation et Modélisation, Instituto de Física de Cantabria, Lagrange Laboratory, Observatoire de la Côte d’Azur, University of the Western Cape, Heidelberg University, Scuola Internazionale Superiore di Studi Avanzati, University of Manchester, University of Ferrara, Ben-Gurion University of the Negev, National Institute of Technology Calicut, Consejo Superior de Investigaciones Científicas, Instituto de Física Teórica, Universidad Autónoma de Madrid, Queen Mary University of London, Stellenbosch University, Uppsala University, Sun Yat-sen University, Chinese Academy of Sciences, National Astronomical Observatories, Ludwig-Maximilians-Universität München
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7166737497