2014/06/02 by F. Lacasa, Lacasa, Fabien
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Geophysics and Gravity Measurements #Scientific Research and Discoveries #Statistical and numerical algorithms
paper · pdf · doi:10.48550/arxiv.1406.0441
openalex publication_date 2014/06/02 · openalex created_date 2022/09/11 · openalex updated_date 2026/07/28
[Abridged] This PhD thesis was defended in September 2013 at Universit 'e\nParis-Sud, France. It studies the non-Gaussianity (NG) of extragalactic\nforegrounds to the Cosmic Microwave Background (CMB). This is particularly\nimportant for the analysis of CMB data from the Planck satellite, in which I\nwas involved. I studied in particular the extragalactic foregrounds tracing the\nLarge Scale Structure (LSS) of the universe : radio and infrared point-sources\nand the thermal Sunyaev-Zel'dovich effect (tSZ).\n The motivations and summary of this thesis cannot be shortened into the\nlength constraints of this abstract and are thus described in an inner abstract\nand introduction.\n In a broad summary, this thesis is organised in the following parts :\nstatistics of random variables and fields, spherical analysis in particular of\npolyspectra, some cosmology (inflation and its NG, CMB, LSS and halo model),\nextragalactic foregrounds (tSZ, point-sources), and measuring the NG of these\nforegrounds with Planck.\n More specifically and in a disorganised manner, the following were most of my\ncontributions in the field : developments on the effect of masking on the\nangular bispectrum, introduction of an efficient bispectrum representation,\nderivation of the bispectrum covariance, generation of non-gaussian\nsimulations, projection of 3D Fourier polyspectra onto 2D spherical ones,\ntreatment of shot-noise terms with the halo model, introduction of a\ndiagrammatic formalism for elegant and simple derivation of galaxy polyspectra,\nhalo model description of the bispectrum of the tSZ effect and of the Cosmic\nInfrared Background (CIB), phenomenological prescription of the NG of clustered\nsources and corresponding KSW-like estimator, effect of point-sources NG for\nPlanck, measurement of the CIB bispectrum with Planck data, measurement of the\ntSZ bispectrum with Planck data and cosmological constraints with it.\n