Dark Energy studies using 21cm Intensity-Mapping with HIRAX and Lensing Detection from Galaxy Number Counts

Diplôme Thèse Dark Energy studies using 21cm Intensity-Mapping with HIRAX and Lensing Detection from Galaxy Number Counts eng 2023 2023 author Nistane Viraj 0000-0002-2165-1393 917102 director Kunz Martin 109032 Département de physique théorique (FITEO) 139 10.13097/archive-ouverte/unige:170706 urn:nbn:ch:unige-1707066 Sc. 5740 <p>This thesis aims to explore the possible explanations of the late-time accelerated expansion of our universe observed by a wide range of astronomical probes based on Earth as well as in space. We perform this study by mainly studying the properties of a mysterious major component called Dark Energy. Chapter 1 describes an upcoming radio-astronomy interferometric telescope in South Africa called Hydrogen Intensity Real-time Analysis eXperiment (HIRAX), the objectives of which include the detection of an observational probe called Baryon Acoustic Oscillation which could help us better understand the properties of Dark Energy. Chapters 2 and 3 describe the indirect study of Dark Energy properties via weak gravitational lensing of Galaxy Number counts in a standard model of our Universe and of the Cosmic Microwave Background for an observer in a large-scale local void universe. Finally, I conclude the thesis in chapter 4 by providing a summarized discussion and a brief outlook on some future possible extensions of this work.</p> Astrophysics Cosmology Cosmic Acceleration Dark Energy Baryon Acoustic Oscillations BAO Radio Astronomy 21cm Cosmology HIRAX Cosmological Forecast Weak Gravitational Lensing Lensing Galaxy Number Counts Euclid LSST CMB Large Scale Structure LTB model Inhomogeneous Cosmology Dewey 500.2 37 Département de physique théorique 133 false 2026bc1d-665a-43ab-bbee-f0585669690f Thesis Public NISTANE_Viraj_manuscrit.pdf 23666925 application/pdf acf8e73e4546cb99c2b337ce1bbc121baf055693244f21f89b936a702bc277f1 7e4675f0-4430-49f5-9f20-088d1016d289 Imprimatur Public imprimatur.pdf 340920 application/pdf bb2c55e208feed71711055c09517cc26022b4cac5a47171af25183e41b183bec Vignette Public hirax_karoo-1-1-1.jpg 288592 openAccess Faculté des sciences / Section de physique / Département de physique théorique

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Dark Energy studies using 21cm Intensity-Mapping with HIRAX and Lensing Detection from Galaxy Number Counts				2023	379	309

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