Diagnostic of Horndeski theories
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Marseille (France)
We study the effects of Horndeski models of dark energy on the observables of the large-scale structure in the late time universe. A novel classification into Late dark energy , Early dark energy and Early modified gravity scenarios is proposed, according to whether such models predict deviations from the standard paradigm persistent at early time in the matter domination epoch. We discuss the physical imprints left by each specific class of models on the effective Newton constant μ, the gravitational slip parameter η, the light deflection parameter Σ and the growth function f σ{sub 8} and demonstrate that a convenient way to dress a complete portrait of the viability of the Horndeski accelerating mechanism is via two, redshift-dependent, diagnostics: the μ( z ) − Σ( z ) and the f σ{sub 8}( z ) − Σ( z ) planes. If future, model-independent, measurements point to either Σ − 1 < 0 at redshift zero or μ − 1 < 0 with Σ − 1 > 0 at high redshifts or μ − 1 > 0 with Σ − 1 < 0 at high redshifts, Horndeski theories are effectively ruled out. If f σ{sub 8} is measured to be larger than expected in a ΛCDM model at z > 1.5 then Early dark energy models are definitely ruled out. On the opposite case, Late dark energy models are rejected by data if Σ < 1, while, if Σ > 1, only Early modifications of gravity provide a viable framework to interpret data.
- OSTI ID:
- 22680080
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 01 Vol. 2017; ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
Constraints on deviations from ΛCDM within Horndeski gravity
Sweeping Horndeski canvas: new growth-rate parameterization for modified-gravity theories