Annuncio Seminari congiunti ASI - Dipartimento Matematica Tor Vergata *9 Gennaio 2020* Aula Dal Passo, Edificio Sogene
*Ore 14: Gianluca Polenta, ASI Space Science Data Centre*
Title: Cosmology through CMB maps
Abstract: The Cosmic Microwave Background is a fundamental source of information for cosmology. In the standard inflationary scenario, the CMB can be described to first order as a Gaussian random field on the sphere, and as such cosmological information is encoded in the two-point correlation function or in the angular power spectrum. To derive these quantities as well as the likelihood function needed to estimate the cosmological parameters, a number of estimators have been developed following different trade-off between optimality, unbiasedness, and computational resources, also depending on the characteristics of the dataset to be analysed. In this talk I will review the different classes of estimators used in the CMB data analysis, focusing in particular to the solutions adopted for the ESA Planck satellite, which produced CMB full sky maps of unprecedented quality. Finally, I will briefly discuss how CMB non-Gaussianity, isotropy, and those anomalies found in the analysis of Planck data can be used to further test the inflationary paradigm.
*Ore 15: Domenico Marinucci, Department of Mathematics, University ofRome Tor Vergata*
Title: Critical Points, Multiple Testing and Point Source Detection for Cosmological Data
Abstract: In this talk, we shall review some mathematical issues arising in the analysis of Cosmic Microwave Background (CMB) radiation data; many of these issues can be related to the investigation of functionals of independent interest in random geometry. We will first review some results on harmonic analysis for spherical random fields, on the construction of spherical wavelets and on their stochastic properties; we will then show how to compute the asymptotic distribution of critical points for Fourier/wavelet components of random fields, and we will establish some ergodicity results, in the high-frequency limit. We will then investigate how to exploit these results to implement multiple testing procedures for detection of point sources (Galaxies) in CMB Data; the resulting tests will be shown to exhibit a number of optimality properties. Applications to CMB data from the Planck collaboration will also be briefly illustrated.
--------- Anna Vidotto
PostDoc Researcher Dipartimento di Matematica Università degli Studi di Roma Tor Vergata