Wilson-Fisher fixed points for any dimension

The critical behavior of a nonlocal scalar field theory is studied. This theory has a nonlocal quartic interaction term which involves a power-β of the Laplacian. The power-β is tuned so as to make that interaction marginal for any dimension. This leads to integer or half-integer values for β, depen...

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Detalhes bibliográficos
Autor: Trinchero, Roberto Carlos
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/123888
Acesso em linha:http://hdl.handle.net/11336/123888
Access Level:acceso abierto
Palavra-chave:Field theory
Renormalization group
Critical behaviour
Non-local
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descrição
Resumo:The critical behavior of a nonlocal scalar field theory is studied. This theory has a nonlocal quartic interaction term which involves a power-β of the Laplacian. The power-β is tuned so as to make that interaction marginal for any dimension. This leads to integer or half-integer values for β, depending on the space dimension. Introducing an auxiliary field, it is shown that the theory can be renormalized by means of local counterterms in the fields. The lowest order Feynman diagrams corresponding to coupling constant renormalization, mass renormalization, and field renormalization are computed. In all cases, a nontrivial IR fixed point is obtained. Remarkably, for dimensions other than 4, field renormalization is required at the one-loop level. For d=4, the theory reduces to the usual local φ4 field theory, and field renormalization is required starting at the two-loop level. The critical exponents ν and η are computed for dimensions 2, 3, 4, and 5. For dimensions greater than 4, the critical exponent η turns out to be negative for ϵ>0, which indicates a violation of the unitarity bounds.