Development of formalism for neutrino evolution in the early universe / Desenvolvimento de formalismo para evolução de neutrinos no universo primordial
AUTOR(ES)
Pedro Accioly Nogueira Machado
DATA DE PUBLICAÇÃO
2009
RESUMO
In this work, we studied some aspects of neutrino physics, using the state vector and density matrix formalisms, with the goal of understanding the neutrino evolution in the primordial universe. In the rst approach, we analysed the phenomenum of neutrino oscillation in vacuum, the induced matter potential and its expression as a refraction index, and the influence of finite temperature efects in such index. We began the second formalism with the study of oscillating two levels systems subject to collisions with media. We derived an evolution equation for the density matrix that describes a neutrino system in the primordial universe. To that end, we used one simplified approach and another based on first principles.
ASSUNTO(S)
mecânica quântica physics física quantum mechanics
