Properties of perturbations in beyond Horndeski theories
arXiv:1712.09909 · doi:10.1142/S0217751X18501555
Abstract
We study whether the approach of Deffayet et al. (DPSV) can be adopted for obtaining a derivative part of quadratic action for scalar perturbations in beyond Horndeski theories about homogeneous and isotropic backgrounds. We find that even though the method does remove the second and higher derivatives of metric perturbations from the linearized Galileon equation, in the same manner as in the general Horndeski theory, it gives incorrect result for the quadratic action. We analyse the reasons behind this property and suggest the way of modifying the approach, so that it gives valid results.
References in corpus (17)
- Healthy theories beyond Horndeski
- Imperfect Dark Energy from Kinetic Gravity Braiding
- G-inflation: inflation driven by the Galileon field
- Towards a Nonsingular Bouncing Cosmology
- Effective Description of Higher-Order Scalar-Tensor Theories
- Generic instabilities of non-singular cosmologies in Horndeski theory: a no-go theorem
- Classically stable non-singular cosmological bounces
- The Effective Field Theory of nonsingular cosmology
- Generalized Galileons: instabilities of bouncing and Genesis cosmologies and modified Genesis
- Cosmological Perturbations Through a Non-Singular Ghost-Condensate/Galileon Bounce
- Stability of Geodesically Complete Cosmologies
- A covariant Lagrangian for stable nonsingular bounce
- Cosmological bounce and Genesis beyond Horndeski
- G-Bounce Inflation: Towards Nonsingular Inflation Cosmology with Galileon Field
- Cosmological bounces and Lorentzian wormholes in Galileon theories with an extra scalar field
- Perturbations in generalized Galileon theories
- Instability of Static Semi-Closed Worlds in Generalized Galileon Theories