Gravidade unimodular como um possível cenário cosmológico
Data
2022-11-05
Autores
Guerini, Thaís da Silva 
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O presente estudo, que constitui um trabalho de conclusão de curso de especialização em Teoria da Relatividade, tem como objetivo solucionar o problema da constante cosmológica com uso da teoria alternativa à Relatividade Geral denominada Gravidade Unimodular. Essa teoria, proposta por Albert Einstein em 1919, tem como característica principal a chamada condição unimodular, na qual o determinante da métrica é constante. As equações de campo obtidas tem uma importante diferença da Relatividade Geral: o tensor momentum-energia pode ou não ser conservado. Nesse panorama, estudamos as implicações da conservação ou não desse tensor, no âmbito cosmológico. Como resultado, encontramos na literatura que ambas as situações podem solucionar o problema da constante cosmológica (ELLIS et al., 2011), (JOSSET; PEREZ; SUDARSKY, 2017). Esse resultado se mostra extremamente interessante e pretendemos realizar análises quantitativas mais detalhadas a fim de determinar o cenário mais provável de acordo com observações cosmológicas e astrofísicas.
The present study, which constitutes a final paper for a specialization course in Relativity Theory, aims to solve the cosmological constant problem based on the alternative theory to General Relativity called Unimodular Gravity. This theory, proposed by Albert Einstein in 1919, has as its main characteristic the so-called unimodular condition, in which the determinant of the metric is constant. The resulting field equations have an important difference from General Relativity: the momentum-energy tensor may or may not be conserved. In this panorama, we study the implications of the conservation or not of this tensor, in the cosmological framework. As a result, we found in the literature that both situations can solve the cosmological constant problem (ELLIS et al., 2011), (JOSSET; PEREZ; SUDARSKY, 2017). This is an extremely interesting result and we intend to perform more detailed quantitative analyses in order to determine the most likely scenario according to cosmological and astrophysical observations.
The present study, which constitutes a final paper for a specialization course in Relativity Theory, aims to solve the cosmological constant problem based on the alternative theory to General Relativity called Unimodular Gravity. This theory, proposed by Albert Einstein in 1919, has as its main characteristic the so-called unimodular condition, in which the determinant of the metric is constant. The resulting field equations have an important difference from General Relativity: the momentum-energy tensor may or may not be conserved. In this panorama, we study the implications of the conservation or not of this tensor, in the cosmological framework. As a result, we found in the literature that both situations can solve the cosmological constant problem (ELLIS et al., 2011), (JOSSET; PEREZ; SUDARSKY, 2017). This is an extremely interesting result and we intend to perform more detailed quantitative analyses in order to determine the most likely scenario according to cosmological and astrophysical observations.