Stochastic semiclassical cosmological models

We consider the classical stochastic fluctuations of spacetime geometry induced by quantum fluctuations of massless nonconformal matter fields in the early Universe. To this end, we supplement the stress-energy tensor of these fields with a stochastic part, which is computed along the lines of the F...

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Detalhes bibliográficos
Autores: Campos, Antonio, Calzetta, Esteban A., 1958-, Verdaguer Oms, Enric, 1950-
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:1997
País:España
Recursos:Universidad de Barcelona
Repositório:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/12308
Acesso em linha:https://hdl.handle.net/2445/12308
Access Level:Acceso aberto
Palavra-chave:Relativitat (Física)
Gravitació
Física estadística
Teoria quàntica
Cosmologia
Relativity (Physics)
Gravitation
Cosmology
Statistical physics
Quantum theory
Descrição
Resumo:We consider the classical stochastic fluctuations of spacetime geometry induced by quantum fluctuations of massless nonconformal matter fields in the early Universe. To this end, we supplement the stress-energy tensor of these fields with a stochastic part, which is computed along the lines of the Feynman-Vernon and Schwinger-Keldysh techniques; the Einstein equation is therefore upgraded to a so-called Einstein-Langevin equation. We consider in some detail the conformal fluctuations of flat spacetime and the fluctuations of the scale factor in a simple cosmological model introduced by Hartle, which consists of a spatially flat isotropic cosmology driven by radiation and dust.