Boundary conditions and vacuum fluctuations in AdS(4)

Autor(es)

Barroso, Vitor S. ^{[1, 2]} ; Pitelli, J. P. M. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas UNICAMP, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil

^[2] Univ Nottingham, Sch Math Sci, Univ Pk, Nottingham NG7 2RD - England

^[3] Univ Estadual Campinas UNICAMP, Inst Matemat Estat & Comp Cient, BR-13083859 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GENERAL RELATIVITY AND GRAVITATION; v. 52, n. 3 MAR 18 2020.
• Citações Web of Science: 0

Resumo

Initial conditions given on a spacelike, static slice of a non-globally hyperbolic spacetime may not define the fates of classical and quantum fields uniquely. Such lack of global hyperbolicity is a well-known property of the anti-de Sitter solution and led many authors to question how is it possible to develop a quantum field theory on this spacetime. Wald and Ishibashi took a step towards the healing of that causal issue when considering the propagation of scalar fields on AdS. They proposed a systematic procedure to obtain a physically consistent dynamical evolution. Their prescription relies on determining the self-adjoint extensions of the spatial component of the differential wave operator. Such a requirement leads to the imposition of a specific set of boundary conditions at infinity. We employ their scheme in the particular case of the four-dimensional AdS spacetime and compute the expectation values of the field squared and the energy-momentum tensor, which will then bear the effects of those boundary conditions. We are not aware of any laws of nature constraining us to prescribe the same boundary conditions to all modes of the wave equation. Thus, we formulate a physical setup in which one of those modes satisfy a Robin boundary condition, while all others satisfy the Dirichlet condition. Due to our unusual settings, the resulting contributions to the fluctuations of the expectation values will not respect AdS invariance. As a consequence, a back-reaction procedure would yield a non-maximally symmetric spacetime. Furthermore, we verify the violation of weak energy condition as a direct consequence of our prescription for dynamics. (AU)

• Processo FAPESP: 13/09357-9 - Física e geometria do espaço-tempo
• Beneficiário: Alberto Vazquez Saa
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/09575-0 - Flutuações do vácuo em espaços-tempos não-globalmente hiperbólicos
• Beneficiário: Vitor Barroso Silveira
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Mestrado