Relative entropy and the RG flow

We consider the relative entropy between vacuum states of two different theories: a conformal field theory (CFT), and the CFT perturbed by a relevant operator. By restricting both states to the null Cauchy surface in the causal domain of a sphere, we make the relative entropy equal to the difference...

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Detalhes bibliográficos
Autores: Casini, Horacio German, Testé Lino, Eduardo, Torroba, Gonzalo
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2017
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositório:CONICET Digital (CONICET)
Idioma:inglês
OAI Identifier:oai:ri.conicet.gov.ar:11336/57963
Acesso em linha:http://hdl.handle.net/11336/57963
Access Level:Acceso aberto
Palavra-chave:CONFORMAL FIELD THEORY
RENORMALIZATION GROUP
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descrição
Resumo:We consider the relative entropy between vacuum states of two different theories: a conformal field theory (CFT), and the CFT perturbed by a relevant operator. By restricting both states to the null Cauchy surface in the causal domain of a sphere, we make the relative entropy equal to the difference of entanglement entropies. As a result, this difference has the positivity and monotonicity properties of relative entropy. From this it follows a simple alternative proof of the c-theorem in d = 2 space-time dimensions and, for d > 2, the proof that the coefficient of the area term in the entanglement entropy decreases along the renormalization group (RG) flow between fixed points. We comment on the regimes of convergence of relative entropy, depending on the space-time dimensions and the conformal dimension Δ of the perturbation that triggers the RG flow.