On the transverse-traceless projection in lattice simulations of gravitational wave production

It has recently been pointed out that the usual procedure employed in order to obtain the transverse-traceless (TT) part of metric perturbations in lattice simulations was inconsistent with the fact that those fields live in the lattice and not in the continuum. It was claimed that this could lead t...

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Detalhes bibliográficos
Autores: Figueroa, Daniel G., García-Bellido, Juan, Rajantie, Arttu
Formato: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2011
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/346680
Acesso em linha:http://hdl.handle.net/10261/346680
https://api.elsevier.com/content/abstract/scopus_id/82955251159
Access Level:acceso abierto
Palavra-chave:Gravitational waves/sources
Gravitational waves/theory
Primordial gravitational waves (theory)
Descrição
Resumo:It has recently been pointed out that the usual procedure employed in order to obtain the transverse-traceless (TT) part of metric perturbations in lattice simulations was inconsistent with the fact that those fields live in the lattice and not in the continuum. It was claimed that this could lead to a larger amplitude and a wrong shape for the gravitational wave (GW) spectra obtained in numerical simulations of (p)reheating. In order to address this issue, we have defined a consistent prescription in the lattice for extracting the TT part of the metric perturbations. We demonstrate explicitly that the GW spectra obtained with the old continuum-based TT projection only differ marginally in amplitude and shape with respect to the new lattice-based ones. We conclude that one can therefore trust the predictions appearing in the literature on the spectra of GW produced during (p)reheating and similar scenarios simulated on a lattice. © 2011 IOP Publishing Ltd and SISSA.