Year: 2019
Type: article
Abstract: We show that theories of mimetic gravity can be viewed as degenerate higher-order scalar-tensor (DHOST) theories that admit an extra local (gauge) symmetry in addition to the usual diffeomorphism invariance. We reformulate and classify mimetic theories in this perspective. Using the effective theory of dark energy, recently extended to include DHOST theories, we then investigate the linear perturbations about a homogeneous and isotropic background for all mimetic theories. We also include matter, in the form of a k -essence scalar field, and we derive the quadratic action for linear perturbations in this case.
Institutions: Centre National de la Recherche Scientifique, Laboratoire AstroParticule et Cosmologie, Université Paris Diderot, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Institut de Physique Théorique, Université de Tours, Université d'Orléans, Institut Denis Poisson
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2787276161