2015/12/31 by Georgios Kofinas, Minas Tsoukalas · 1 citation
Physics and Astronomy · #Action (physics) #Black Holes and Theoretical Physics #Conformal symmetry #Cosmology and Gravitation Theories #Einstein #Field theory (psychology) #Principle of least action #Pulsars and Gravitational Waves Research #Scalar (mathematics) #Scalar field #Scalar field theory #Scalar theories of gravitation #gr-qc #hep-th
paper · pdf · doi:10.1140/epjc/s10052-016-4505-y
To appear in EPJC; minor changes
openalex created_date 2016/06/24 · arxiv created 2016/11/28 · openalex publication_date 2016/12/01 · arxiv updated 2017/02/01 · openalex updated_date 2026/08/05
Recently the most general completion of Brans–Dicke theory has appeared with energy exchanged between the scalar field and ordinary matter, given that the equation of motion for the scalar field keeps the simple wave form of Brans–Dicke. This class of theories contain undetermined functions, but there exist only three theories which are unambiguously determined from consistency. Here, for the first such theory, the action of the vacuum theory is found, which arises as the limit of the full matter theory. A symmetry transformation of this vacuum action in the Jordan frame is found which consists of a conformal transformation of the metric together with a redefinition of the scalar field. Since the general family of vacuum theories is parametrized by an arbitrary function of the scalar field, the action of this family is also found. As for the full theory with matter the action of the system is only found when the matter Lagrangian vanishes on-shell, as for example for pressureless dust. Due to the interaction, the matter Lagrangian is non-minimally coupled either in the Jordan or the Einstein frame.