Particle production in the early universe and its application to problems of astrophysics and cosmology

Author(s)

Ana Helena de Campos

• Document type: Doctoral Thesis
• Press: São Paulo. , gráficos, ilustrações, tabelas.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2004-09-13

Examining board members

Rogério Rosenfeld; Elcio Abdalla; Luis Raul Weber Abramo; Carlos Ourivio Escobar; José Ademir Sales de Lima

• Advisor: Rogério Rosenfeld
• Field of knowledge: Physical Sciences and Mathematics - Physics
• Indexed in: Banco de Dados Bibliográficos da USP-DEDALUS
• Location: Universidade de São Paulo. Biblioteca do Instituto de Física; C198p D

Abstract

We studied three applications of the mechanisms of particle production in the early universe. Although such mechanisms were first proposed to reheat the universe they were used lately to produce supermassive particles. The production of supermassive or massless particles depends mainly on the inflationary model that we work with. Here, we chose the chaotic inflationary models generated by one scalar field, the inflaton. In the first application we studied the production of supermassive particles by the non-perturbative instant preheating mechanism. We used cosmic ray flux and cold dark matter observational data to constrain the parameters of the model, since we are supposing that such particles may account for a fraction of the cold dark matter as well as decay into high energy cosmic rays. In the second application we perform a numerical study of the instant preheating mechanism of particle production in a model of quintessential inflation. Such inflationary models are used to explain the dark energy that seems to dominate the universe nowadays. We obtained the reheating temperatures allowed by this mechanism. The third application studied the supermassive particle production by a perturbative mechanism to explain high energy cosmic rays. The inflaton would have decayed into such particles after inflation. By constraining their lifetime and present abundance we obtained the branching ratio of such decay. (AU)