Semi-dynamical perturbations of unified dark energy

Abstract

Linear cosmological perturbations of a large class of modified gravity and dark energy models can be unified in the effective field theory of cosmic acceleration, encompassing Horndeski scalar-tensor theories and beyond. The fully available model space inherent to this formalism cannot be constrained by measurements in the quasistatic small-scale regime alone. To facilitate the analysis of modifications from the concordance model beyond this limit, we introduce a semi-dynamical treatment extrapolated from the evolution of perturbations at a pivot scale of choice. At small scales, and for Horndeski theories, the resulting modifications recover a quasistatic approximation but account for corrections to it near the Hubble scale. For models beyond Horndeski gravity, we find that the velocity field and time derivative of the spatial metric potential can generally not be neglected, even in the small-scale limit. We test the semi-dynamical approximation against the linear perturbations of a range of dark energy and modified gravity models, finding good agreement between the two.

26 pages, 4 figures

References in corpus (32)

• Quantum Gravity at a Lifshitz Point
• Beyond the Cosmological Standard Model
• Healthy theories beyond Horndeski
• Cosmological Tests of Modified Gravity
• The Large Scale Structure of f(R) Gravity
• Exploring gravitational theories beyond Horndeski
• A Parameterized Post-Friedmann Framework for Modified Gravity
• Maximal freedom at minimum cost: linear large-scale structure in general modifications of gravity
• Measuring the dark side (with weak lensing)
• A discriminating probe of gravity at cosmological scales
• New Perspective on Galaxy Clustering as a Cosmological Probe: General Relativistic Effects
• Distinguishing Modified Gravity from Dark Energy
• The Effective Theory of Quintessence: the w<-1 Side Unveiled
• Anisotropic stress as signature of non-standard propagation of gravitational waves
• Testing gravity with CAMB and CosmoMC
• A unifying description of dark energy
• Current constraints on the cosmic growth history
• On the Growth of Perturbations as a Test of Dark Energy
• The Parameterized Post-Friedmann Framework for Theories of Modified Gravity: Concepts, Formalism and Examples
• The acceleration of the universe and the physics behind it
• How to optimally parametrize deviations from General Relativity in the evolution of cosmological perturbations
• Limits of Quasi-Static Approximation in Modified-Gravity Cosmologies
• Constraints on a New Post-General Relativity Cosmological Parameter
• Constraining chameleon models with cosmology
• Measuring the speed of cosmological gravitational waves
• Effects of modified gravity on B-mode polarization
• A sub-horizon framework for probing the relationship between the cosmological matter distribution and metric perturbations
• The effective field theory of inflation/dark energy and the Horndeski theory
• Possibility of realizing weak gravity in redshift space distortion measurements
• Friction in Gravitational Waves: a test for early-time modified gravity
• Observational signatures of the theories beyond Horndeski
• Classifying Linearly Shielded Modified Gravity Models in Effective Field Theory

Cited by in corpus (26)

• Breaking a Dark Degeneracy with Gravitational Waves
• Effective Field Theory of Dark Energy: a Review
• Hamiltonian analysis of higher derivative scalar-tensor theories
• The Novel Probes Project -- Tests of Gravity on Astrophysical Scales
• Effective Theory of Dark Energy at Redshift Survey Scales
• Observational signatures of modified gravity on ultra-large scales
• Gravity at the horizon: on relativistic effects, CMB-LSS correlations and ultra-large scales in Horndeski's theory
• Weakening Gravity on Redshift-Survey Scales with Kinetic Matter Mixing
• Reconstructing Horndeski theories from phenomenological modified gravity and dark energy models on cosmological scales
• A parametrisation of modified gravity on nonlinear cosmological scales
• Gravity's Islands: Parametrizing Horndeski Stability
• $N$-body simulations for parametrised modified gravity
• Fast and accurate predictions of the nonlinear matter power spectrum for general models of Dark Energy and Modified Gravity
• Reconstructing Horndeski models from the effective field theory of dark energy
• Comparison of different approaches to the quasi-static approximation in Horndeski models
• Inherently stable effective field theory for dark energy and modified gravity
• Modelling the matter bispectrum at small scales in modified gravity
• Constraints on decaying early modified gravity from cosmological observations
• Parametrizations for tests of gravity
• Parameterised post-Newtonian formalism for the effective field theory of dark energy via screened reconstructed Horndeski theories
• Dark sector evolution in Horndeski models
• The effect of screening mechanisms on black hole binary inspiral waveforms
• Screening and degenerate kinetic self-acceleration from the nonlinear freedom of reconstructed Horndeski theories
• Dynamics of cosmological perturbations in modified Brans-Dicke cosmology with matter-scalar field interaction
• Cosmic magnification in beyond-Horndeski gravity
• Probing beyond-Horndeski gravity on ultra-large scales