70256 20200117213749.0 doi 10.3390/galaxies6010023 sideral 105344 ART-2018-105344 eng (orcid)0000-0003-3669-6241 Asorey, M. Universidad de Zaragoza Unitary issues in some higher derivative field theories 2018 Access copy available to the general public Unrestricted We analyze the unitarity properties of higher derivative quantum field theories which are free of ghosts and ultraviolet singularities. We point out that in spite of the absence of ghosts most of these theories are not unitary. This result confirms the difficulties of finding a consistent quantum field theory of quantum gravity. info:eu-repo/grantAgreement/EUR/COST/MP1405-QSPACE info:eu-repo/grantAgreement/ES/DGA/E24-2 info:eu-repo/grantAgreement/ES/MINECO/FPA2015-65745-P info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 0.591 2018 Astronomy and Astrophysics 2018 Q3 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Rachwal, L. Shapiro, I. 2004 405 Universidad de Zaragoza Dpto. Física Teórica Área Física Teórica 6, 1 (2018), 23 [7 pp] Galaxies Galaxies 2075-4434 232654 http://zaguan.unizar.es/record/70256/files/texto_completo.pdf Versión publicada 97466 http://zaguan.unizar.es/record/70256/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:70256 articulos driver 2020-01-17-21:31:30 ARTICLE