The Greisen-Zatsepin-Kuzmin Effect in the vicinity of black holes

Author(s)

Gabriel Bernardi de Freitas

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Física Gleb Wataghin
• Defense date: 2011-11-03

Examining board members

Alberto Vazquez Saa; Daniel Augusto Turolla Vanzella; Marcelo Moraes Guzzo

• Advisor: Marcus Aloizio Martinez de Aguiar; Alberto Vazquez Saa

Abstract

The aim of this work is the investigation of the Greisen-Zatsepin-Kuzmin (GZK) effect in the presence of black holes, thereby consisting of an astrophysical correction for the propagation of ultrahigh energy cosmic rays. Firstly, a description of the main features of the two crucial elements involved in the effect, the ultrahigh energy cosmic rays and the cosmic microwave background, is given. Then, a systematic review of the GZK effect is presented, showing the most relevant interactions and the approach used for the calculation of energy losses. Also, special attention is given to the cosmological corrections that must be incorporated when very far cosmic-ray sources are considered. After that, the problem is analysed in the presence of a black hole. The study is based upon the simplest situation: the cosmic microwave background is treated as a thermal bath in which a Schwarzschild black hole is immersed, constituting a system whose evolution can be treated in the quasi-static approximation (adiabatic changes). An approximation for the cosmic-ray particles¿ trajectories is proposed, and then used to calculate the energy loss for each particle as a function of the maximum approximation distance to the black hole. Finally, the author¿s conclusions are presented, as well as perspectives for future investigations (AU)

• FAPESP's process: 08/07404-1 - Introduction to quantum field theory on curved spacetimes
• Grantee: Gabriel Bernardi de Freitas
• Support Opportunities: Scholarships in Brazil - Master