Estudo De Lentes Gravitacionais E Algumas Aplicações Para Astrofísica De Neutrino

Abstract

Delgado Insuasty, Edwin Alexander; Nunokawa, Hiroshi (Advisor). Study of gravitational lenses and some applications to astrophysics of neutrino. Rio de Janeiro, 2013. 97p. MSc Dissertation -Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro.. In the present work I carried out an review of the elementary theory of gravitational lensing. It is mainly emphasizing to study the effect it would have neutrino mass in the time delay of signals from distant sources which are deflected due to the presence of a mass distribution that acts as a lens. To do this, for the mass values provided by neutrino oscillation, beta decay experiments and cosmology, we study the present contribution of cosmic background neutrinos to energy density of universe. Based on these results, it was made a comparison between the angular diameter distance measurement for an allowed neutrino mass and the value of the distance when the mass is zero. All this was done from the perspective of the standard cosmological model under two possible cases for the normalization condition of the energy density parameters present in the universe: first, when the radiation and cosmological energy density parameters are fixed and second when the parameters for matter and radiation are fixed. It was found that the effect of the neutrino mass on time delay measurement is negligible for the first case and has a contribution of the order of one percent for the second case.