Maximum a-posteriori Lensing Reconstruction for CMB Science

Diplôme Thèse Maximum a-posteriori Lensing Reconstruction for CMB Science eng 2024 2024-11-06 director Carron Julien 935832 Département de physique théorique (FITEO) author Belkner Sebastian 947010 Département de physique théorique (FITEO) 188 10.13097/archive-ouverte/unige:181650 urn:nbn:ch:unige-1816502 Sc. 5856 <p>This thesis is dedicated to advancing our understanding of the origin and evolution of the Universe by studying the cosmic microwave background (CMB), a light travelling through the cosmos since the dawn of time. The CMB contains rich information about the earliest time of the Universe, and informs us about the Universe as a whole due to it containing an imprint of the mass distribution of the Universe. We study this imprint through the development and application of a novel curved sky Bayesian analysis method. This comprehensive approach, inclusive of carefully treating biases, is designed to effectively handle real observational data and is aimed at tackling cosmological phenomena captured through the CMB.</p> <p>Central to this thesis is the improvement of a Bayesian method, dubbed the Maximum a-posterior (MAP) lensing reconstruction. The MAP method optimally recovers the lensing information and is therefore an improvement over standard quadratic estimators (QE). Our Bayesian approach iteratively finds the MAP point of the deflection field, which makes this approach computationally more expensive than the QE. This is in particular true due to the full sky treatment for which spherical harmonics are the basis functions; their numerical calculation is more expensive than their flat sky counterpart, the Fourier basis.</p> Dewey 500.2 37 Département de physique théorique 133 false 1447 Groupe Carron 3cfad29f-d6f4-4917-ba81-ef001697a641 Thesis Public ThesisPhD_submissionArchiveRev1.pdf 26040523 application/pdf CC BY-4.0 df7ca20fbf97cfd0ebab8b2f40706f2aaf732a7a47518aba482bbc92736516d2 45d1194e-7402-42bb-a44b-9abfdff3e914 Imprimatur Public IMG_9152.pdf 515920 application/pdf f375986d9bc92053d5dcabae8b942c3d0b2a50752e9687beefe804b6375e7e7d openAccess Faculté des sciences / Section de physique / Département de physique théorique

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Maximum a-posteriori Lensing Reconstruction for CMB Science				2024	292	197

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Belkner, Sebastian

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