2021/03/28 by Katsuki Aoki, Francesco Di Filippo, Shinji Mukohyama
Physics and Astronomy · #Classical mechanics #Cosmology and Gravitation Theories #Field theory (psychology) #Gamma-ray bursts and supernovae #General relativity #Gravitation #Gravitational wave #Graviton #Massless particle #Mathematical physics #Physics #Pulsars and Gravitational Waves Research #Quantum mechanics #Theoretical physics #Universe #gr-qc
paper · pdf · doi:10.1088/1475-7516/2021/05/071
19 pages, 1 figure
arxiv created 2021/03/28 · openalex publication_date 2021/05/01 · arxiv updated 2021/06/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract We study a theory of minimally modified gravity called cuscuton/VCDM that propagates only two gravitational degrees of freedom. Despite being apparently different from general relativity (GR), it is in principle possible that this theory might be obtained via a field redefinition starting from the GR action. This would make the vacuum theory equivalent to GR and the theory would differ from GR only in the presence of matter. In this paper, studying the dispersion relation of gravitational waves and the dynamics of the Bianchi-I universe, we prove that such a field redefinition does not exist and that the theory differs from GR already in vacuum.