Cattaruzza, EltiGozzi, E.Francisco Neto, Antônio2015-05-222015-05-222011CATTARUZZA, E.; GOZZI, E.; FRANCISCO NETO, A. Diagrammar in classical scalar field theory. Annals of Physics, v. 326, p. 2377-2430, 2011. Disponível em: <http://www.sciencedirect.com/science/article/pii/S000349161100100X>. Acesso em: 09 abr. 2015.0003-4916http://www.repositorio.ufop.br/handle/123456789/5451In this paper we analyze perturbatively a gφ4 classical field theory with and without temperature. In order to do that, we make use of a path-integral approach developed some time ago for classical theories. It turns out that the diagrams appearing at the classical level are many more than at the quantum level due to the presence of extra auxiliary fields in the classical formalism. We shall show that a universal supersymmetry present in the classical path-integral mentioned above is responsible for the cancelation of various diagrams. The same supersymmetry allows the introduction of super-fields and super-diagrams which considerably simplify the calculations and make the classical perturbative calculations almost ‘‘identical’’ formally to the quantum ones. Using the super-diagrams technique, we develop the classical perturbation theory up to third order. We conclude the paper with An perturbative check of the fluctuation-dissipation theorem.en-USClassical field theoryFeynman diagramArtigo publicado em periodicoO periódico Annals of Physics concede permissão para depósito deste artigo no Repositório Institucional da UFOP. Número da licença: 3621890591052.https://doi.org/10.1016/j.aop.2011.05.009