Aether-quasi-dilaton massive gravity

Abstract

Although quasi-dilaton massive gravity is a well-defined gravitational theory, it exhibits instabilities and suffers from the strong coupling problem. In this work we construct an extension of the theory, through the inclusion of the aether field. Focusing on flat Friedmann-Lemaitre-Robertson-Walker geometry, we show the existence of exact, self-accelerating solutions at the background level, characterized by an effective cosmological constant arising from the graviton mass. Additionally, we perform a detailed perturbation analysis, investigating separately the tensor, vector, and scalar perturbations, extracting the dispersion relation of gravitational waves, and determining the stability conditions for vector and scalar sectors. As we show, there are always regions in the parameter space in which the obtained solutions are free from ghost instabilities, as well as from the strong coupling problem. Hence, although the aether field does not play an important role in the background self-accelerating solutions, it does play a crucial role in the alleviation of the perturbation-related problems of the simple quasi-dilaton massive gravity.

version to appear in Phys.Rev.D

References in corpus (25)

• Dynamics of dark energy
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Quantum Gravity at a Lifshitz Point
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• Resummation of Massive Gravity
• Dark torsion as the cosmic speed-up
• Covariant Galileon
• Models of non-relativistic quantum gravity: the good, the bad and the healthy
• Teleparallel equivalent of Gauss-Bonnet gravity and its modifications
• Massive gravity: nonlinear instability of the homogeneous and isotropic universe
• Quasi-Dilaton: Theory and Cosmology
• Lorentz Violating Inflation
• Signals for Lorentz violation in gravitational waves
• Cosmology in cubic and $f(P)$ gravity
• On the growth of structure in theories with a dynamical preferred frame
• Bigravity and Lorentz-violating Massive Gravity
• Cosmological perturbations in massive gravity with doubly coupled matter
• Cosmic alignment of the aether
• Lorentz Violation in Goldstone Gravity
• A new quasidilaton theory of massive gravity
• Cosmological perturbation theory in Generalized Einstein-Aether models
• Cosmology of a Lorentz violating Galileon theory
• Role of matter in extended quasidilaton massive gravity
• Cosmology and perturbations in tachyonic massive gravity
• Stable cosmology in ghost-free quasidilaton theory