Estudo de espectros de potências cosmológicos linear da matéria e angular de 21-cm.

Abstract

The spectra of observable cosmological powers contain a range of information about the evolution of the Universe. They are used to restrict cosmological parameters through data extraction, for example, the Baryonic Acoustic Oscillations and thus, investigate the characteristics of dark components, mainly dark energy, considered as responsible for the current phase of expansion of the Universe. In view of this, our study provides the basic theoretical foundations necessary for understanding and formulating the power spectra: linear of matter and angular of 21-cm. Throughout this dissertation we approach the basic principles of cosmology, cosmological observations, Baryonic Acoustic Oscillations and the 21-cm line. In addition, we discuss the theory of linear cosmological fluctuations, in which we find the function of growth of matter disturbances and present the Boltzmann equations. We obtain the mathematical expressions of the linear power spectra of matter and angular 21-cm, we report some experiments that provide (or will provide) data to Model these spectra and that help to improve the values of the cosmological parameters. We show textitfittings of power spectra that we have reproduced and some obtained by other works. We present definitions of power spectra of a Cosmological Model of Interaction between dark matter and dark energy that we intend to study in the future, in order to analyze the growth of large-scale structures.