On tachyonic stability priors for dark energy
arXiv:2107.01044 · doi:10.1103/PhysRevD.105.064002
Abstract
A number of stability criteria exist for dark energy theories, associated with requiring the absence of ghost, gradient and tachyonic instabilities. Tachyonic instabilities are the least well explored of these in the dark energy context and we here discuss and derive criteria for their presence and size in detail. Our findings suggest that, while the absence of ghost and gradient instabilities is indeed essential for physically viable models and so priors associated with the absence of such instabilities significantly increase the efficiency of parameter estimations without introducing unphysical biases, this is not the case for tachyonic instabilities. Even strong such instabilities can be present without spoiling the cosmological validity of the underlying models. Therefore, we caution against using exclusion priors based on requiring the absence of (strong) tachyonic instabilities in deriving cosmological parameter constraints. We illustrate this by explicitly computing such constraints within the context of Horndeski theories, while quantifying the size and effect of related tachyonic instabilities.
arXiv comment17 pages, 9 figures
References in corpus (83)
- Planck 2015 results. XIII. Cosmological parameters
- The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
- The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 10 and 11 galaxy samples
- The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
- Cosmological Constraints from the SDSS Luminous Red Galaxies
- Generalized G-inflation: Inflation with the most general second-order field equations
- Planck 2018 results. V. CMB power spectra and likelihoods
- From k-essence to generalised Galileons
- Dark Energy after GW170817: dead ends and the road ahead
- Strong constraints on cosmological gravity from GW170817 and GRB 170817A
- Conservative Constraints on Early Cosmology: an illustration of the Monte Python cosmological parameter inference code
- Dark Energy after GW170817 and GRB170817A
- Implications of the Neutron Star Merger GW170817 for Cosmological Scalar-Tensor Theories
- Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters
- Imperfect Dark Energy from Kinetic Gravity Braiding
- The 6dF Galaxy Survey: z \approx 0 measurement of the growth rate and sigma_8
- Action functionals for relativistic perfect fluids
- Maximal freedom at minimum cost: linear large-scale structure in general modifications of gravity
- Breaking a Dark Degeneracy with Gravitational Waves
- The Clustering of Galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS): measuring growth rate and geometry with anisotropic clustering
- Challenges to Self-Acceleration in Modified Gravity from Gravitational Waves and Large-Scale Structure
- Conditions for the cosmological viability of the most general scalar-tensor theories and their applications to extended Galileon dark energy models
- Anisotropic stress as signature of non-standard propagation of gravitational waves
- Effective Field Theory of Cosmic Acceleration: an implementation in CAMB
- Effective Field Theory of Dark Energy: a Review
- Speed of Gravitational Waves and the Fate of Scalar-Tensor Gravity
- Effective Field Theory of Cosmic Acceleration: constraining dark energy with CMB data
- hi_class: Horndeski in the Cosmic Linear Anisotropy Solving System
- Generalized framework for testing gravity with gravitational-wave propagation. II. Constraints on Horndeski theory
- Observables and unobservables in dark energy cosmologies
- Gravitational Wave Decay into Dark Energy
- The Observational Future of Cosmological Scalar-Tensor Theories
- Piercing the Vainshtein screen with anomalous gravitational wave speed: Constraints on modified gravity from binary pulsars
- Constraints on Shift-Symmetric Scalar-Tensor Theories with a Vainshtein Mechanism from Bounds on the Time Variation of G
- Weakly Broken Galileon Symmetry
- The non-adiabatic pressure in general scalar field systems
- Cosmological parameter constraints for Horndeski scalar-tensor gravity
- Constraints on deviations from CDM within Horndeski gravity
- Reconstructing Gravity on Cosmological Scales
- Cosmological Constraints on Horndeski Gravity in Light of GW170817
- Dark-Energy Instabilities induced by Gravitational Waves
- Effective Theory of Dark Energy at Redshift Survey Scales
- Positivity in the sky
- Measuring the speed of cosmological gravitational waves
- Effects of modified gravity on B-mode polarization
- Phenomenology of the generalized cubic covariant Galileon model and cosmological bounds
- A note on the equivalence of a barotropic perfect fluid with a K-essence scalar field
- hi_class: Background Evolution, Initial Conditions and Approximation Schemes
- Action approach to cosmological perturbations: the 2nd order metric in matter dominance
- KiDS+GAMA: Constraints on Horndeski gravity from combined large-scale structure probes
- Phenomenology in minimal theory of massive gravity
- The correspondence between a scalar field and an effective perfect fluid
- Relativistic hydrodynamics with sources for cosmological K-fluids
- Is the Effective Field Theory of Dark Energy Effective?
- Positivity Bounds on Dark Energy: When Matter Matters
- Designing Horndeski and the effective fluid approach
- Jeans' Ghost
- The road ahead of Horndeski: cosmology of surviving scalar-tensor theories
- Constraining Scalar-Tensor Modified Gravity with Gravitational Waves and Large Scale Structure Surveys
- Challenges in Connecting Modified Gravity Theory and Observations
- Cosmological constraints on dark energy in light of gravitational wave bounds
- Testing (modified) gravity with 3D and tomographic cosmic shear
- Resonant Decay of Gravitational Waves into Dark Energy
- A general theory of linear cosmological perturbations: stability conditions, the quasistatic limit and dynamics
- Optimising growth of structure constraints on modified gravity
- Testing Gravity on Cosmic Scales: A Case Study of Jordan-Brans-Dicke Theory
- Parametrizing modified gravity for cosmological surveys
- Gravity's Islands: Parametrizing Horndeski Stability
- Forecasts on the speed of gravitational waves at high
- Non-standard gravitational waves imply gravitational slip: on the difficulty of partially hiding new gravitational degrees of freedom
- On the stability conditions for theories of modified gravity in presence of matter fields
- The role of the tachyonic instability in Horndeski gravity
- Investigating scalar-tensor-gravity with statistics of the cosmic large-scale structure
- Inherently stable effective field theory for dark energy and modified gravity
- Horndeski under the quantum loupe
- Constraining the cosmological evolution of scalar-tensor theories with local measurements of the time variation of G
- Radiative stability and observational constraints on dark energy and modified gravity
- Modified Gravity Away from a CDM Background
- Are Scalar and Tensor Deviations Related in Modified Gravity?
- Scalar-tensor cosmologies without screening
- Positivity bounds on reconstructed Horndeski models
- Cosmological Instabilities and the Role of Matter Interactions in Dynamical Dark Energy Models
- A de Sitter limit analysis for dark energy and modified gravity models