Abstract
Symmetries that exist for some theories when considering small perturbations around some special backgrounds, which include flat but not de Sitter space and, among cosmological solutions spatially flat but generally not k=\ifmmode\pm\else\textpm\fi{}1 Robertson-Walker solutions, are studied. The models examined include theories of nonconformally coupled massless fields, Brans-Dicke theories, and some supergravity theories with a dilaton field. The uses and possible consequences of these symmetries, among them the fact that they should help define the quantum vacuum in certain cosmologies, are discussed. Possible mechanisms which may solve the cosmological and flatness problems in which these symmetries play a role are also discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.