2015/12/30 by Katrin Hammer, Hammer, Katrin, Alexander Vikman +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Noncommutative and Quantum Gravity Theories #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.48550/arxiv.1512.09118
10 pages, no figures
arxiv created 2015/12/30 · openalex publication_date 2015/12/30 · arxiv updated 2015/12/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We consider the recently introduced mimetic gravity, which is a Weyl-symmetric extension of the General Relativity and which can play a role of an imperfect fluid-like Dark Matter with a small sound speed. In this paper we discuss in details how this higher- derivative scalar-tensor theory goes beyond the construction by Horndeski, keeping only one scalar degree of freedom on top of two standard graviton polarizations. In particular, we consider representations of the theory in different sets of Weyl-invariant variables and connect this framework to the singular Brans-Dicke theory. Further, we find solution of equations of motion for the mimetic gravity in the synchronous reference frame in a general curved spacetime. This solution is exact in the test-field approximation or in the case of a shear-free spacetime without any other matter.